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HELP - No start cold. I have tried it all (I think)

3K views 22 replies 5 participants last post by  guitarnut 
#1 ·
She won't start cold. By cold I mean less than 50-55 degrees (give or take).
I did new UVCHs, new GPs (ford), new relay (well, 3 of them). I also changed the oil to 5w40 synthetic and added 2 bottles of RevX. I run the archoil fuel additive. At 60, she starts fine. Plugging in the block heater makes no difference. It is getting power because it is warm.

So, monitoring it this morning I can see (and hear) the GP Relay going and carguage confirms it is on. I have also tested using a voltmeter to verify the relay is sending power when it is on (you can hear it hum). My injection pressure is over 500 (usually around 1200) when I crank. I have new batteries, a new starter, and a new CPS (did a second new one just in case so I have a spare in the glovebox). A KOEO test says system pass. The injector buzz test buzzes all injectors and they all make the same sound (one isn't significantly quieter than the other).

She cranks over fine but won't start. The RPMs are showing and not dropping off. I'll get some whiteish/greyish smoke if I keep cranking. I'll go home this afternoon, it will be 59 outside and she'll fire right up not plugged in.
 
#2 · (Edited)
Plugging in the block heater makes no difference.
that's completely odd.....WHEN BLOCK HEATER PLUGGED in you should have zero issues...
EOT = 90°F when IAT = FREEZING OR BELOW.
CHECK YOUR ENGINE BLOCK HEATER?

can you see the voltage drop on the meter when the GP are on?
.....increase when they turn off?

FOR ME:
GPIL = 6 seconds (a joke indicator light)
GP ON time = 84 seconds at IAT = 38°F, EOT = 45°F

voltage will go from 12 v to 11.4 volt when GP ON
then jump up to 11.88 or so when GP turn off.

I have done as many as 5 FULL GP BURNS 84 SECONDS EACH.......
at 40°F or below and using my cold start tune no problems.

although at freezing/8000' on trips I stay plugged in for 3 days if I can!
have a propane generator for powering the block heater if no grid power

Depends more on fuel mixes .....??
NOT ALL DIESEL IS CREATED EQUAL!

i COULD cold start better before changing injectors, removing EPBV, FUEL BOWL/HEATER......going efuel
..also have all new GP/BIG RELAY, rebuilt alternator
so i have today arriving some fuel filter heaters!
will install and test and post results...

 
#4 ·
I'll respond to both here:
I can't measure EOT only ECT since it is a manual there is no EOT sensor. It doesn't come up on my scanner but ECT does. My GPS will stay on up to 2 minutes. I can hear it and the scanner says so. All of my filters are less than 3000 miles (fuel, oil, etc).

This morning I tested, using a multimeter, the block heater and it shows that I am getting continuity the full circuit. I can feel it get warm and i use the amp meter setting and see voltage being drawn (or amperage, pardon me if I use the wrong terms). I also know the cable is good because before I figured out how to use the multimeter i shocked the he77 out of myself.

I checked the continuity of all GPs (all new) using the ohm setting and all but 1 show "continuity." Oddly enough, the 1 is on the drivers side which is a pain. 1 bad GP shouldn't affect starting? I really don't want to remove that valve cover if I don't have to.

I also get this oddity, the GP relay will cycle on and off for a couple seconds, while it does this the WTS light also goes on and off. Sometimes during this process, the CEL will alternate with the WTS but doesn't throw a code. You can hear it clicking on and off and see the voltage meter on the dash move when it does this. I took a screwdriver and manually jumpered the 2 posts of the GPR for about 45 seconds and tried to start and nothing. Crank but no start.

We have 1 local diesel shop and they don't know what they are doing so my only other option is ford. While their labor rate is the same as other shops you know how they love to throw unnecessary parts at anything to push up the bill.

Any advice is appreciated. Again, it is a 95 F250 7.3
 
#5 ·
There is no ECT sensor tied to the PCM on any of our trucks. And they all have an EOT sensor. Both our trucks have 5-speeds and they have EOT sensors. Sounds like your device isn't communicating properly.

A GP that reads "continuity" constitutes a dead short to ground. This would explain the cycling relay; on our trucks the relay should NEVER cycle like that. The lights and GPR cycling indicate the short is causing the voltage to drop, so the PCM powers down; this de-energizes the GPR, so the voltage recovers, the PCM re-energizes and the cycle starts all over. It's a surprise the fusible links powering the hot terminal of the GPR haven't burned. For the time being, you might try disconnecting that one errant GP and see what happens. It might also be the wire to that GP under the valve cover that's shorting to ground. But that's where I'd point the troubleshooting.

Clueless local diesel shop is not unusual, and not really their "fault" they're clueless. As time passes, our trucks and their systems are inexorably passing into the esoteric realm of "oh yeah my dad worked on one of those" vehicles. Ford dealer is NOT your "only" other option. A good study of the FSMs and reference to this and the other forums are your other, most viable, options.
 
#6 ·
When I say continuity I may be using that word incorrectly. It should read 0 if there is a connection and 1 if not. So, the display says 1 and when I touch the tester ends together it reads 0. I am saying that continuity means it reads 0 as 1 means there is no connection. So, I am probably using that term incorrectly. All GPs read 0 except number 3 which reads 1. If I take an extension cord and jumper it, then it reads 0, otherwise, it reads 1 (no continuity or connection).

Oddly enough, the GP won't do that click on and off BS if it is over about 50-55. At this temperature, I runs as it should as I can hear it energizing the GPs and verify it via the tester. I am going to try to figure out where the EOT is. I think I know so maybe I'll see if I can get a replacement at advance or somewhere and install it today. If not I'll order it from riffraff or dieselorings.

Where would I find a FSM?

Any other advice from anyone is greatly appreciated.
 
#8 ·
When I say continuity I may be using that word incorrectly. It should read 0 if there is a connection and 1 if not. So, the display says 1 and when I touch the tester ends together it reads 0. I am saying that continuity means it reads 0 as 1 means there is no connection. So, I am probably using that term incorrectly. All GPs read 0 except number 3 which reads 1. If I take an extension cord and jumper it, then it reads 0, otherwise, it reads 1 (no continuity or connection).
Don't bother with a "yes/no" tester. Use an ohmmeter.

Oddly enough, the GP won't do that click on and off BS if it is over about 50-55. At this temperature, I runs as it should as I can hear it energizing the GPs and verify it via the tester. I am going to try to figure out where the EOT is. I think I know so maybe I'll see if I can get a replacement at advance or somewhere and install it today. If not I'll order it from riffraff or dieselorings.
EOT sensor is on the HPO reservoir. Three-wire connector, if memory serves. First you have to get your device to recognize it, before you know whether it needs to be replaced.

Where would I find a FSM?
Helm, Inc., or eBay. There are CD/DVD versions as well.
 
#7 ·
For checking the injector/glowplug wiring:

From each valvecover gasket connection's outermost pins (2 per connector) to ground you should get 0.1 to 2 ohms (indicates good plug and wiring)
I GET 0.7-0.8 OHM

From each valvecover gasket connection's center pin to each immediately adjacent pin, you should get around 3-4 ohms (indicates good injector solenoid and wiring).
I GET 2.7-2.8 OHM

You should not get any continuity from any of the outer pins to the 3 inner pins (indicates no shorts between injector and glowplug wiring).
AMENS WHAT i GOT!

You should also get 0 to 1 ohms from each of the external harness connectors outer pins back to the Glowplug Relay's large terminal on the GP side (indicates good wiring from external connections back to the relay).
I GET 0.8 OHM
 
#9 ·
My scanner won't read EOT but reads ECt which is odd (blue elm and carguage pro). I found the eot and it tests ok. My next questions are:
1. Why would the gpr be cycling on and off at 40 degrees but at 55 it works fine (1 bad gp).
2. Even if eot sensor is bad wouldn't it assume the same temp each time causing it to behave the same at 40 and 60?

Thanks for all the help. I am not mechanically inclined but am learning with your help.
 
#10 ·
You could try jumping the glow plug relay with a screw driver with the key in the "wait to start" position and make sure the relay is functioning fine. I have often just bridged the two large posts with the screwdriver for 15/20 seconds then hop in and see if it will start.
 
#11 ·
Nothing has changed since post #5 (or since the truck was built, for that matter). By no stretch of the imagination is your scanner able to read ECT, since ECT is not an input to the PCM. If you're getting an ECT value but not getting an EOT value, I would question the settings on the scanner.

Even with inop sensors, the GP relay should NEVER (another thing that hasn't changed....) cycle. That most likely indicates an electromechanical (i.e. electrical, NOT electronic) short to ground. Did you ever measure the RESISTANCE of the glow plugs?
 
#14 ·
This one has me stumped. I am still thinking there is something fishy with the glow plug system. You have tested everything though. SO when its cold out, you cycle the key on and with a volt meter you have 12 volts at both large terminals of the glow plug relay? I know you said the indicatior gauge shows lower voltage like its loaded.... 50 degrees sounds far to warm for fuel gelling, but have you checked fuel pressure when its cold like that? The cold fuel is more viscous, maybe your filter has restriction, or the fuel pressure regulator screen is clogged. Kind of grasping at straws here. You could still get the smoke if the fuel is moving, albeit heavily restricted . That still doesnt make much sense though, 50 isnt even cold....

I will keep thinking and see if I can come up with any other ideas, but I am really leaning on the glow plug system.
 
#15 ·
Yes, it cycles when it is less than about 50 but I just jumper it to force it to energize the glow plugs. I would think that should take the GP system out of the equation. I verified I am getting power. Over 50ish, it doesn't cycle. Jumpering should take out the GP from the equation.

I still can't read EOT but if the PCM isn't getting an EOT it should throw a code. I get no such code. I do intermittently get a turbo wastegate code but that isn't when it won't start. I think that has to do with the glowshift gauge spliced into the line.

According to my glowshift gauge I am getting fuel pressure.

I have been using cargauge pro but I am going to see if I can get torque to work. It can't do buzz tests or KEKO but maybe it can read my EOT.

I think there is something small and stupid going on. It is just odd that at less than 50 the PCM keeps cycling the relay but at 50ish the relay charges and has no issues.
 
#16 ·
Below 50 it cycles? You mean turns off and on again repeatedly?
 
#17 ·
Yes. Cycles in and off verified by a multimeter. 3 gprs do the same. Over 50 no issues. Sometimes the cel comes on and off with no code. New gp all around and ucvh too. I verified all but 1 gp is getting power. Jumping the gpr doesn't help. Icp and ipr duty are good. Buzz test sounds good too. I am lost.
 
#18 ·
Your truck doesn't have a wastegate, unless it's custom. If the GPs are cycling, you still most likely have a power problem. To confirm, check GPR run time at startup, below and above 50F. It should only be slightly different. Have you load tested the batteries, and checked that all battery / ground connections are clean and tight and strong?

Failed sensors do not always throw codes. Example - the EOT might be constantly reporting, say, 70F, and the PCM would never have any clue that that's wrong.
 
#19 ·
recently for me at 9000 ft block heater plugged in...

IAT = 28°F
EOT=85°F
and GP burn time was still 85 seconds, i still do a full burn, then turn ignition off...
and then just start her up somewhere in the second GP burn time.

seems the GP burn time has lots of inputs f(EOT,IAT, pressure) but as mentioned, unless they are all up to 'room temperature'
there will be at least one minute of burn time.
Otherwise, the actually oil temperature seems to be the overriding factor for ease of start, not fuel temperature or intake air temperature?
makes sense since that's the inertia to be overcome when cold. 5w rotella for me.

i will say that a few years back after i changed injectors, I noticed the GPIL nonsense light used to stay on longer, but of course never show true burn time.
I monitor battery voltage to see when/how long the GP are burning. 11.9 off, 11.44 on.

It takes about a minute for the alternator voltage to get back up to the charging value of 14.5v when running.
New batteries, and a rebuilt alternator 2 years back, it helped to have stronger voltages.

loose grounds can generate heat.......even had my alternator glow red hot when the connection was loose a few years back.
melted the connector, hence I had it rebuilt completely.
 
#20 ·
I was finally able to read EOT. After sitting all night eot is 59 and the outside temp is 46. Icp jumps up to about 3000 when trying to start but no start. When running icp is 600 to 800 on idle and up to 2000 when driving. The GPs are running about 1.5 minutes. I did 2 burns and they burned less the second time. Still, no start. I get some white smoke but it isn't smoking out the neighborhood or anything like i have seen with stiction issues. My glowshift guage shows good fuel pressure. I'll try later today once it warms up and see what eot is.

Any ideas are appreciated.
 
#21 ·
Sorry I haven't been on. It has been warm down here in Savannah, GA. We hit a cold snap and it was 45 this morning. I had the block heater and EOT read 86. It won't start. ICP goes up to about 1200, my fuel pressure gauge from glow shift reads good, EBP = 14.9, glow plugs are staying on for about 90 seconds as verified by a multi-meter and the scanner (says 89 secs). Multiple cycles of the GPs and she still doesn't start. Again, all the GPs and UCVH are new and getting signal to the injectors via buzz test. I am running 5w40 synthetic.

around 55 degrees she fires right up. so, given the above, my thought is it can't be injectors or it would start with the block heater. Anyone have any ideas?
 
#22 ·
What kinda voltage are you getting from the batterys? My truck cut off the other day while warming up (i wasnt home, and dad was taking it) I tried everything and was checking all the sensors, at least everything I am capable of checking. Ended up hooking my other truck to it with battery cables and it fired up. No clue as to what caused it to shut off.
 
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