Ford Powerstroke Diesel Forum banner

1 - 20 of 31 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
How it came when I bought it in June with 230,000 miles:
2002 F250 7.3L diesel Lariat 4 door 6.5' bed; aftermarket intake, 6"lift, 37" mudding tires, off-roading heavy duty front bumper with LED lights, non-functioning EGT pyrometer and turbo boost gauges, nice sounding speakers (may be aftermarket), plastic bed liner insert

Most recent maintenance:
Installed fuel pressure gauge after installing new fuel pressure regulator spring & plunger, engine started up a little slow but okay (as previously) and had over 100psi fuel pressure; pulled fuses for fuel pump and ECM and relay for IDM to do a compression test; did HPOP deadhead test and cylinder compression test and HP oil system leak test, replaced fuses/relays, clipped spring in fuel pressure regulator (fuel pressure still high), now it won't start just cranks.

Original Symptoms:
Hard start cold and sometimes no start hot; low power and acceleration, especially at medium to high speeds or higher RPMs, couldn't accelerate past 72 ish MPH on level roads; twice I got the “injection pressure not controllable” check engine code – one of the times while driving that resulted in almost no power, but I pulled over, let the engine sit, cleared the code, turned it back on, and got home fine; engine was starting but now just recently is not, fuel pressure was over 100psi with new pump on (engine running or off) and dropped to mid 50s with pump off (and engine off), but after clipping the fuel pressure regulator spring it reads high 90s with pump on & 60s with it off (don't know what it will read while the engine is running because now it won't start), recently checked HPOP reservoir to find it very low but manually added oil to it and it showed no signs of the level lowering after 2 days of sitting,

Currently healthy readings:
HPO pump read 3400psi when deadheaded, no leaks from HP oil system with shop air hooked up to it and IPR closed, passenger side cylinders all read 350psi during cold compression test, when last running the boost pressure would get up to 18-20 psi tops and pyrometer EGT gauge would build up to and hold at around 700 deg F on the highway, HPOP reservoir not draining, healthy LP oil pressure as read on dashboard, fuel can be heard running through return line while pump is on, no visible or audible leaks anywhere,

Things I had a shop do to address low power issue:
Run cylinder contribution test - 3&5 failing intermittently with low temperature while #1 read a good temperature and #7 had a medium temperature, replaced all passenger side injectors & glow plugs & valve cover gasket, replaced LPR & ICP sensor, replaced spring and plunger in fuel pressure regulator (was still high after that and that's when I clipped the spring). Had an expert shop diagnose it after replacing only the 3&5 injectors, and the guy said that fuel pressure was really high, but that shouldn't be causing the low power - do a compression test on the passenger side cylinders, and if they show good compression, then replace the 1&7 cylinders and that should fix it. I went forward with replacing the 1&7 cylinders to see if that would work and did the compression test after that didn't fix the issue (compression looked fine).

Things I did to address low power issue:
Checked oil level to ensure it was in spec, installed new CPS (purple one from amazon that was highly recommended), installed new fuel filter, installed new fuel pump, installed fuel pressure gauge, used fuel injector cleaning additive in fuel (Lucas brand), checked fuel screens in tank (looked super clean but I replaced them anyway), blew compressed air through fuel return line to ensure it wasn't clogged and removed spring and plunger from fuel pressure regulator to ensure fuel could flow freely back to tank (pressure held at 0 as expected when that was done), clipped fuel pressure regulator spring to lower pressure (was still high after shop swapped parts), cleaned air filter and replaced broken air filter restriction gauge which reads almost nothing now, added Hot Shot's Stiction Eliminator to oil and drove for over an hour before changing oil (& filter) and adding Archoil AR9100 oil additive post oil change, did a cold compression test to all 4 passenger side cylinders and they all read 350psi, deadheaded HPOP and it read 3400psi, hooked up compressed air to both sides of HP oil system and found one leak at ICP (post shop replacing it) so I changed the O-ring on it and had no leaks after that (haven't been able to get it started again after making that fix to see if it will run better)

Other fixes I did:
replaced tailgate latch, repaired overhead console display, installed aftermarket stereo with reverse camera and cell phone screen replication ability, replaced reverse lights with really bright LED lights, replaced headlights with aftermarket ones, replaced cruise control switch, replaced clockspring to regain functionality of cruise control & driver side airbag & horn, placed seat cover over passenger seat to hide tear in leather, installed rear shocks (they were missing), replaced sway bar end links and bushings (they were causing clunking in suspension- now fixed), installed cell phone holder, swapped steering wheel shift lever to regain "overdrive off" indication, replaced hood struts, fixed EGT pyrometer gauge & boost gauge and backlights to both, cleaned EBPS & tube (neither of which looked bad), replaced windshield wipers, fixed windshield fluid low spraying flow

Any ideas what the issue could be? Someone suggested IDM, but when I took it to a diesel mechanic who did a full diagnostic, he said there were no IDM codes, so that wasn't an issue. I ordered and will soon have a USB ScanTool, so I will be able to read everything from the OBD2 interface on my laptop.

Thanks!
 

·
Registered
Joined
·
1,858 Posts
If you "clipped" the regulator spring (something I've never heard of doing before) then how do you know that the regulator isn't holding pressure in the fuel rail and now the truck won't start because of zero fuel pressure?

Chances are the original spring wasn't seated correctly in the regulator giving you the 100+ psi of fuel pressure.
 

·
Premium Member
Joined
·
8,483 Posts
Soooo,,, what's low HPOP oil level to you?

You seem focused on Fuel Pressure, I would pay more attention to HPOP pressure (when it's not starting, when you can't go past 70mph). During all this, what is the IPR %? (how much trouble are you having making that pressure).

What is it you've been using to scan for codes and monitor sensors? What, exactly was it you've ordered? Have you read this thread for advice on scan apps (are you Apple/Android/Win?) -> Ford SuperDuty Diagnosis on the Cheap
 

·
Registered
Joined
·
971 Posts
you need to do an injector buzz test and report back. That high of fuel pressure will absolutely make your truck run like crap and I have experienced it when I put the regulator spring in and had over 100 psi according to my attometer gauge. I think you may just simply have air in fuel lines from the aeration of the high pressure diesel.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #5 (Edited)
Thanks for the replies so far. I just downloaded ForScan, awaiting arrival of my ScanTool tomorrow (ScanTool OBDLink SX - a reviewer on Amazon said he had a lot of success using it with his 7.3).

I originally thought that, based on the symptoms, there had to be a leak in the HP oil system or a dying HPOP. I figured I would address the high fuel pressure in parallel in case that was also causing issues.

Low oil level in the HPOP resevoir was definitely far below the recommended 1" below the top of the resevoir. It was around 1" total from the bottom; not more than 2".

New IPR Valve: Amazon.com: SPELAB 7.3 IPR & ICP Fuel Injection Pressure Regulator Control Sensor for 1997-2003 Ford 7.3L V8 Powerstroke Diesel Econoline Excursion Super Duty F250 F350 F450 F550 F650 F750 E350 E450 E550: Automotive
Amazon.com: SPELAB 7.3 IPR & ICP Fuel Injection Pressure Regulator Control Sensor for 1997-2003 Ford 7.3L V8 Powerstroke Diesel Econoline Excursion Super Duty F250 F350 F450 F550 F650 F750 E350 E450 E550: Automotive
ICP's: I purchased several because on the first replacement I purchased, the threads didn't match up correctly. I don't know which one of these is currently installed, but I have 2 with bad threads and one currently in the truck:
-The one that came with the IPR
Amazon.com: F6TZ-9F838-A Injection Control Pressure ICP Sensor for Ford 7.3L Powerstroke Diesel 1994-2003 Replaces 1807329C92 F4TZ-9F838-A CM5227 112841: Automotive
ICP Injection Control Pressure Sensor For Ford INT 7.3 7.3L Powerstroke Diesel | eBay
I still have this one on standby: Amazon.com: Ford 7.3 ICP Sensor with Pigtail Connector, Fits 1997-2003 Ford 7.3L Diesel Engines Powerstroke, Injection Control Pressure Sensor: Automotive
Amazon.com: F6TZ-9F838-A Injection Control Pressure ICP Sensor for Ford 7.3L Powerstroke Diesel 1994-2003 Replaces 1807329C92 F4TZ-9F838-A CM5227 112841: Automotive
Fuel pressure regulator internals were replaced by a shop with these parts: Amazon.com: XtremeAmazing Fuel Pressure Regulator Valve Cap Spring and Seal Kit Fits for Ford 7.3L Powerstroke Diesel: Automotive
Fuel pressure was measured by a mechanical gauge to be high after installation, but the truck still ran and with the same loss of power issue still present. I then removed the spring and poppet/plunger, turned the key on to give power to the fuel pump, and saw that pressure was not building. I don't recall seeing a hole in the poppet, but I can check again. However, it was at this point that I figured the fuel was able to return to the tank mostly unhindered, so the high pressure must be cause by too much pressure on the poppet by the spring, and I clipped the spring. I then put the spring and poppet/plunger back in the regulator, turned the key to "on," and got the 90s/60s reading on the fuel pressure gauge as described above. I still have this kit on standby: Fuel Pressure Regulator Blue Spring Kit 1999.5-2003 Ford 7.3L Powerstroke Diesel | eBay .

I plan on hooking the HPOP gauge back up and monitoring on the ScanTool while cranking
Battery voltage
ICP reading
IPR duty cycle
FUELPW
RPM

Will post results.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #6
you need to do an injector buzz test and report back. That high of fuel pressure will absolutely make your truck run like crap and I have experienced it when I put the regulator spring in and had over 100 psi according to my attometer gauge. I think you may just simply have air in fuel lines from the aeration of the high pressure diesel.
erbilabuc how would I check for air in my fuel lines? Where would that air be coming in from, and how would I fix it?

The shop in town that did the work above had all injectors passing the injector buzz test. I will see if I can find a way to do that myself in case they decided to fail since then.
 

·
Premium Member
Joined
·
8,483 Posts
OK so, 1-2" from the Bottom of the HPOP reservoir isn't right. That would have me thinking that at higher RPM & Load, like on the hiway, you could be running out of HiPres Oil (gotta check that once your stuff arrives).

The next thing is, you've made a Big Mistake in buying cheap sensors (we always recommend Genuine Ford / IH sensors ONLY). This might well be your problem too.

If I could speak for erbilabuc, and he has a Very interesting point with excessive fuel pressure, that the air would come from that excessive pressure causing aeration in the lines. Something he has seen so I believe him (I am though, not so sure how this would cause a No Start...)
 

·
Registered
Joined
·
14 Posts
Discussion Starter #8 (Edited)
OK so, 1-2" from the Bottom of the HPOP reservoir isn't right. That would have me thinking that at higher RPM & Load, like on the hiway, you could be running out of HiPres Oil (gotta check that once your stuff arrives).

The next thing is, you've made a Big Mistake in buying cheap sensors (we always recommend Genuine Ford / IH sensors ONLY). This might well be your problem too.

If I could speak for erbilabuc, and he has a Very interesting point with excessive fuel pressure, that the air would come from that excessive pressure causing aeration in the lines. Something he has seen so I believe him (I am though, not so sure how this would cause a No Start...)
you need to do an injector buzz test and report back. That high of fuel pressure will absolutely make your truck run like crap and I have experienced it when I put the regulator spring in and had over 100 psi according to my attometer gauge. I think you may just simply have air in fuel lines from the aeration of the high pressure diesel.

Update:
I don't have the scanners yet, although I did also order the means to do an injector buzz test on my own.

However,
I checked the fuel pressure after it was sitting overnight, and it was still at 20psi. I pulled the poppet from the fuel pressure regulator and saw that there was no bypass hole in the center for pressure to drain while the key was off. I drilled my own small hole in the poppet and put it back in. Fuel pressure then topped out at 20psi - too low. At least I was getting somewhere. I then replaced the clipped spring with the blue "upgraded" spring and put it back together; it then fluctuated between holding at high 90s to 110+ depending on how hard the pump was trying (or so it seemed). I clipped the blue spring and put it back - now reading between 55-65psi, usually holding steady at 62psi, which by my understanding is pretty perfect, or at least good enough that it should beyond question not cause an issue. It then drains down to 0 after the pump turns off. I also have the OEM fuel pressure rebuild kit on order just in case.

MORE IMPORTANTLY TO THE NO-START CONDITION
I hooked up a gauge to driver side HP oil, started turning the engine over, and I was not getting any pressure in the gauge. I hooked up the IPR to 12v using a separate wiring harness and noticed that the normal wiring harness was loose - potentially the problem. Once the IPR was forced fully closed, I tried cranking again, and still no pressure. This was inconsistent with the previous HPOP test that resulted in around 3400psi. I tried again - the pressure started building, so I turned it off. Hooked up the IPR to controlled voltage and tried again, no pressure. Put the IPR back on solid 12V and cranked, this time noe pressure. No pressure regardless of whether or not ICP was plugged in. I hooked up shop air to the HP oil system and no leaks. De-powered the IPR and the pressure relieved through it. Applied power again, and the IPR shut. Cranked again with no HP oil pressure. Battyer voltate was 12.5-13.3V before cranking, sometimes dropped down to 9 while cranking, and engine RPM as measured through a basic OBD2 scanner was around 150 while cranking. I don't think any of those would keep it from starting, but worth noting just for good measure. The issue now is that I'm not getting any pressure (ZERO pressure) in the HP oil system while cranking. No leaks, and the HPOP WAS putting out a ton of pressure the last time I deadhead tested it (within the last week or two). I'm a bit stuck here. It's acting like the HPOP isn't kicking on anymore. Any ideas what might be preventing it from turning on or building pressure given that the leak test came back clean?
HPOP resevoir is still full.
 

·
Registered
Joined
·
700 Posts
Is there oil in the reservoir when you got a no pressure reading? Also, 1-2” of oil in the reservoir could indicate a low pressure oil problem. The LPOP feeds the HPOP reservoir.

The gasket at the base of the HPOP has a screen in it, and I’ve seen them have lots of gunk in them. Maybe it’s partly or mostly clogged. Or your LPOP isn’t putting out the pressure/volume that it should

Just throwing things out there..


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
4,456 Posts
Make sure your IPR valve is not over tight, no more than 20 foot pounds
Do you hear the IPR valve click each time you power it with 12 volts?

ForScan for PC is free to download and the Phone/Tablet version is like 4.99
the BAFX or ODBLink MX+ adapters work well

Could be the HPOP is bad, they have a weak swash plate locating pin, that will allow the internals to rotate and randomly pump oil
if the reservoir is full, and you hear the IPR valve click with 12 volts -- then oil pressure should build when you have the gauge on the HPOP

The engine may start and run on just one bank with your gauge on the other, if all else is working
the two high pressure lines are teed together inside the pump

If the HPOP reservoir is low, the LPOP may not be pumping enough oil or the reservoir gasket may be leaking
I would want to put a gauge in the low pressure system to know if there is pressure
 

·
Registered
Joined
·
14 Posts
Discussion Starter #11
Is there oil in the reservoir when you got a no pressure reading? Also, 1-2” of oil in the reservoir could indicate a low pressure oil problem. The LPOP feeds the HPOP reservoir.

The gasket at the base of the HPOP has a screen in it, and I’ve seen them have lots of gunk in them. Maybe it’s partly or mostly clogged. Or your LPOP isn’t putting out the pressure/volume that it should

Just throwing things out there..


Sent from my iPhone using Tapatalk
I checked, and there is still oil in the reservoir (never left after being manually filled). Although there could additionally be a LPOP problem, the last time I had it running, the oil pressure reading on the dash was dead center on the gauge. I'm assuming that means normal. Is that gasket the same one that you get when you buy an HPOP reealing kit like this one? High Pressure Oil Pump Oring+Quick Disconnect Tool+IPR Seal Kit+Base Gasket 7.3L | eBay
If not, where in the oil flow path is it?

I guess I won't know about LPOP output pressure until I can get the truck started again, but then I can double check it.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #12
Make sure your IPR valve is not over tight, no more than 20 foot pounds
Do you hear the IPR valve click each time you power it with 12 volts?

ForScan for PC is free to download and the Phone/Tablet version is like 4.99
the BAFX or ODBLink MX+ adapters work well

Could be the HPOP is bad, they have a weak swash plate locating pin, that will allow the internals to rotate and randomly pump oil
if the reservoir is full, and you hear the IPR valve click with 12 volts -- then oil pressure should build when you have the gauge on the HPOP

The engine may start and run on just one bank with your gauge on the other, if all else is working
the two high pressure lines are teed together inside the pump

If the HPOP reservoir is low, the LPOP may not be pumping enough oil or the reservoir gasket may be leaking
I would want to put a gauge in the low pressure system to know if there is pressure
Thanks, I downloaded ForScan. The HPOP could be bad, but if it is, then it had to have crapped out since the previous HPOP deadhead test at which it built 3400 psi, and that test was less than a week prior. I checked both HP oil sides for leaks and found none. Is it mechanically possible for one side to have pressure and the other side not? Either way, the engine isn't starting period right now - not just only running on one side. I suppose I can check both sides once I get it started again.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #13
As for the batteries, I admittedly don't know how old they are. One has a sticker that said "02/20," but I don't know if that means 02/20 is beginning of life or end of life. I took both batteries to autozone today, and they tested them and told me that both were good but only at around 60-70% charge. I'm assuming that may explain the low voltage while cranking, and I will try again tomorrow when I have the batteries back from them fully charged. I may have been drawing too much power from them and not replacing enough through the jumper cables from my camaro.

The mechanical gauge could potentially be failing, but it's a new gauge, and it was working during the previous HPOP deadhead test, as well as that one blip where the HPOP did build pressure while deadheaded and I turned the engine off. I feel like a failed mechanical gauge wouldn't behave sporadically like that.

The starter is a possibility, although if that were the case, wouldn't it cause the cranking to not reach 150 RPMs? Meaning, if the starter was designed to operate on a given amount of power, and it was dumping power, wouldn't that decrease the designed performance?

Thanks again for the support. I'll report back tomorrow.
 

·
Registered
Joined
·
700 Posts
The gasket you have pictured is the one that goes between the HPOP and front cover. This is the one I was talking about, it goes under the HPOP reservoir


Not saying this is your issue, but for the price and how easy it is to change, it can’t hurt


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
14 Posts
Discussion Starter #15
UPDATE:
1) Got the fully charged and checked batteries back and installed. Hooked up the scanner to FORScan on my laptop. Closed IPR by applying 12V, and still had mechanical gauge hooked up, ICP unplugged. Kept my camaro running with jumper cables hooked up. Cranked for about 5 seconds.
a) RPMs stayed between 150 and 170 => starter seems good
b) Battery voltage never dropped below 10.6V and stayed at around 10.7 while cranking => applying adequate power and voltage
c) FUELPW at 3.19 while cranking
d) Mechanical gauge showed no pressure => problem
e) fuel pressure read 70-80psi on mechanical gauge
2) Plugged normal engine computer (ECM/PCM?) back into IPR and plugged in ICP. Cranked for 6 seconds.
a) RPMs = same as before
b) FUELPW dropped back to 0.6 => my understanding is that's normal.
c) ICP as measured on FORScan slowly built up to 41psi => still a problem
d) IPR started at about 33 and slowly ramped up to and held at 65 => at least there isn't some weird tuning messing with it (I think)
e) fuel pressure measured 70-80psi on mechanical gauge
3) Tried cranking again, this time deciding that I would go for longer if necessary to see if the gauge ever builds pressure - maybe there's still air in the HP oil header/s from my leak tests that needs to be flushed. After about 4 seconds, the engine finally started. Graphs attached. It took a while to steady out; there was probably still air in the HP oil header.
a) It was until ICP got over 500 that the RPMs picked up (as expected)
b) Once the engine started, my LPOP gauge on the dashboard read at the center of the gauge => LPOP appears to be working fine.
c) I only measured battery voltage while my camaro was still hooked up, so I guess I'll have to measure it again to make sure the alternator is good, although I think that would be a separate and currently non-interfering issue.
d) Fuel pressure increased significantly to over 90psi while the engine was running => I guess I still have to fix this.
4) After the engine finally steadied out while idling, I read the following numbers as shown in picture "idling":
a) ICP: ~530-700psi, mostly consistent with mechanical gauge => It appears that HPOP driving gears are functioning as expected
b) IPR: about 17%
c) FUELPW: 3.22 ms
d) RPM: about 700
e) fuel pressure still over 90psi => I guess I really do still have to fix this (Motorcraft FPR internals on the way).
5) I took it for a test drive. My laptop died, so I wasn't able to log anything, but the previous issue persisted. Drove about 2 miles out, 1.5 miles to gas station, then 1.5 miles home.
a) low power, especially uphill. I didn't take it on the freeway
b) engine occasionally cut out while idling. Starting engine again varied from 3-7 seconds of cranking (I just watched the gauge until HPO pressure built and then it fired up)
c) right as I returned, engine code P1211 appeared - ICP above desired.

Tomorrow's agenda:
1) cut aftermarket fuel pressure regulator spring again to try to bring fuel pressure below 70psi while running
2) test drive and log parameters, especially with throttle floored and while going uphill.
3) compare highest HPO gauge measurement to highest ICP measurement to ensure consistency of ICP.

I'm not sure if this is just a computer comms issue, but there were two ICP measurements in FORScan. One appeared to give me very jumpy readings while one read smoothly (see start_2). Don't know if this is an indicator of an issue with the ICP, an issue with the engine's computers, or just normal.

Thoughts/comments are appreciated!
 

Attachments

·
Registered
Joined
·
14 Posts
Discussion Starter #16
Guys, thanks for the continued help and advise. I really appreciate it. Here's the update:

-All gauge measurements of HPO pressure were pretty consistent with PID ICP output, so I'm going to assume that the ICP is good.
-All start-ups only took about 3 seconds and without help of camaro jumper cables => starter is likely good, and the gear drive on the HPOP is also likely sufficiently tight.
-Battery had a voltage of 12.7+ V at the end of a ~30 minute drive and held at 13.8V to 14V while being charged by the alternator => alternator is likely good (not that that was a possible explanation for symptoms).
-Without assist of jumper cable and a camaro, the batter voltage held at around 10.9V while cold cranking and only momentarily dropped to 10.3 at the onset of the crank. => battery appears to be good.
-At a steady 3000 RPM, I was able to hold almost 3000psi on ICP with IPR DC at about 51%. At longest duration of WOT, IPR never went above 55. I'm assuming that means that my HPOP is good and that my IPR is good.
-I did a buzz test on the injectors and they all buzzed, so I'm assuming that means that all electronics and wires going from IDM to injectors are good (right?)
-EBP read about 15psi at idle and up to 52psi at ~3000RPM WOT, => I don't know if that's normal, but I think it should at least mean that my EBPS is good and that the tube isn't clogged, right?
-While kept in first gear, at 3000 RPM WOT I got about 22psi of turbo boost => turbo and piping appears to be functioning properly
-EGT Pyrometer held at 700 deg F on the highway when the truck had been warmed up and working hard => I believe that's a good sign.
-I checked the HPOP reservoir before the first drive and between drives, and it always looked topped off. Additionally, LPOP pressure on dash remained steady => LPOP seems to be delivering enough oil to HPOP without significant leaks, drainage, or blockage.
-FUELPW was 0.6 while cranking, high 1's to low 5s while idling and through most driving conditions, between 0.6 & 2 while decelerating => not sure if that's good or bad, but it at least seems to be cycling in a controlled manner. There does not seem to be much of a correlation between amount of throttle applied and length of FUELPW other that it's under 2 when decelerating.
-Throttle Position Rate stayed at 0 the entire time, and Throttle Mode stayed "PT" the entire time => not sure if that's an issue
-While cold idling, ICP was 750-900 while IPR was 40-42% => seems a little high to me for both. For the cold run, Fuel pressure was idling at 70+, then on the highway WOT would drop down to 60+ => maybe the truck was trying to make high ICP to balance out high fuel pressure?
-While idling warm on that same first run with that same fuel pressure, IPR would be 4.7 and ICP high 500s to mid 600s => again, ICP seems a bit high.
-After several iterates of removing, clipping, and re-insterting the FPR spring, driving, seeing improvement, and repeating, the fuel pressure on my last drive was about 62psi at idle and as low as 45psi WOT on the highway. After that, the warm idle measurements were IPR: high 4s to mid 5s and ICP: 460 to ~550psi - still seems like it might still be a bit high.
-Power on first run with 70+psi idle: significant performance increase over previous driving, BUT still a huge lack of power. Couldn't accelerate past ~75mph on flat highway, and struggled to maintain 45mph with overdrive off up a steep highway hill. Struggled to pick up speed on the on-ramp.
-Power on final run with ~62psi idle: still better performance over first run, but still not what I would think to be normal. Accelerated only up to 84mph on flat highway; struggled to maintain ~47mph on that same hill, and still needing at least 10 extra seconds on the highway to reach highway speeds after merging from on-ramp. I understand that big tires and a 6" lift will detract some power, but it can't explain THAT much power loss, right?
-The only inadvertent idle while stalling occurred at the very end of the last drive => I'm not sure what to make of that. It would previously inadvertently stall while idling, usually while the engine is warm. I'm not sure what to make of that. It stalled when I pulled partially into the driveway and placed it in reverse to straighten out - then stall.

After clearing codes and doing the final run (30+ minutes), I did not have a "check engine" light, but FORScan still read the following codes:
No codes on ODB2
Code: B1352 - Ignition key in circuit fault (is this because I took out the piece that makes the car beep when the key is in the ignition and the ignition in "off"?)
Code: P1000 - On-Board Diagnostic (OBD) Systems Readiness Test Not Complete (sounds like this is not an indicator of a problem, but that it still might be)
Code: P0470 - Exhaust Back Pressure sensor circuit malfunction (this is one I don't understand because the EBPS seemed to be working on the oscilloscope)
Code: P1876 - Transfer Case 2-Wheel Drive Solenoid Circuit Open Or Short To Ground (not sure what to make of that one)

Questions:
1) Was my assumption about the meaning of a successful buzz test correct?
2) a) Can I assume that the EBPS is functioning as designed? b) are those normal readings?
3) Does the FUELPW behavior indicate any issues?
4) Should I continue to lower my fuel pressure to see if the performance still gets better? I don't want to cut it too low. How low should it get before I start worrying that it's too low? I've heard anywhere from mid 40s to mid 50s is normal, but idk if that's idling or WOT.
5) What might that last idling stall be an indicator of given the other readings?
6) Given the above indications, what's the next thing I should be checking/looking for?

Thanks, guys! Codes are attached in .txt ,
 

Attachments

·
Registered
Joined
·
137 Posts
Couple things the way I view them:
Cleaning all of your grounds may help that viewed cranking voltage. Assuming you are looking through the PCM. Never hurts, and helps some platforms run better considering how electronic they are. Like a tune up for a 6.0
EBP readings are absolute? I believe. So 15 at idle, you are seeing atmospheric pressure, not added pressure. Atmospheric at sea level ~14.7psi
That being said, you may be maxing out the EBP sensor. May be an indication that your EBP valve on the turbo is closed or sticking? That will cause labored acceleration, increasing with RPM.
That oil pressure reading on the dash is no better than a dummy light. It only tells you pressure is present, no indication of how much.
The PCM doesn't monitor fuel pressure at all. It makes no adjustments for that. Not sure what a leaking O-ring from high fuel pressure symptom would be.
My understanding is under 45 psi fuel pressure will damage injectors. Over 70 can be hard on or force fuel past fuel O-rings on the injectors. Not sure of symptoms though.
Stalling could be any of those major sensors, with CPS being most common. Not sure about the recommendations on that CPS, but, back in the day, different color CPS would affect timing. Power was lost or gained with a CPS, with no other changes. Tin nut on the IPR being loose causes stalling, along with loose or oil filled connectors.

Now I feel dirty for speaking to a Camaro owner...
 
  • Like
Reactions: mattm_ and Hydro

·
Premium Member
Joined
·
8,483 Posts
None of your sensor reading stand out to me, your Voltage, Fuel Pressure, and ICP are all fine.

This is not though; " Accelerated only up to 84mph on flat highway; struggled to maintain ~47mph on that same hill, and still needing at least 10 extra seconds on the highway to reach highway speeds after merging from on-ramp. "

What are your boost reading during this? You're going uphill, WOT (I assume) and not getting above 50mph. Your boost should be maxed-out at that point.
 

·
Registered
Joined
·
47 Posts
Here's what I see after reading the whole thread:

You've changed a bunch of parts and had both the fuel and oil system open. Assuming you have boost under wide open throttle going uphill...I would go back to a Motorcraft FPR and drive the snot out of it for good while, like 100 miles. My theory is that you have air in both systems that needs to work it's way out. The oil system should be easiest to clear but fuel can be a bugger because of the deadheaded fuel rails in the heads.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #20
None of your sensor reading stand out to me, your Voltage, Fuel Pressure, and ICP are all fine.

This is not though; " Accelerated only up to 84mph on flat highway; struggled to maintain ~47mph on that same hill, and still needing at least 10 extra seconds on the highway to reach highway speeds after merging from on-ramp. "

What are your boost reading during this? You're going uphill, WOT (I assume) and not getting above 50mph. Your boost should be maxed-out at that point.
Thank you for validating that. Although I didn't take down my boost reading during that event, I did note the proper functioning of the turbo at a different time, when it got up to 22psi at 3000 RPM. The amount of boost I get appears to be proportional to RPM, meaning that I can't get more boost until my RPM goes up. I don't know if it's supposed to be like that. It looks like I did have pretty high RPM while going uphill, so I'm willing to assume that I had plenty of boost.

So if I understand correctly, you're thinking that the air won't flow through the lines as fast as the fuel, and that it essentially sticks to the pipe walls or something while the fuel goes by? Would this then happen every time you drained and refilled your fuel bowl?
 
1 - 20 of 31 Posts
Top