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Engine stutter

7K views 30 replies 9 participants last post by  Nashotah7 
#1 ·
Mine's a '96 with almost 200K miles on the engine. Just last week, the engine started lugging like it was not running on all cylinders. The check engine light will come on, then out of nowhere go out and the engine will run fine. I drove the truck around this afternoon and kept recreating the same issue. Then, went to get a haircut and it ran fine all the way to the barber shop. Came out, fired it up, and the truck literally limped all the way home, with the CEL on. I thought it might be the batteries, because after starting the truck, the batt level is down near the "8" line. Maybe alternator? From what I have read so far in different threads is that it could be the valve cover harness??? Already tried changing the CPS and no fix with that. Any suggestions?
 
#2 ·
im very interested if you get some responses. my 97 just developed the exact same thing today. start up fine then cel comes on an it shakes and wont rev. it limps down the road, then light goes off and it runs fine. It seems to only do it after start-up until the motor warms up a bit. i was thinking maybe some type of sensor?
 
#4 ·
Check all your external valvecover harness connections for evidence of melting/burning. Also look to see if there is oil inside the connections (there shouldn't be and indicates the feedthrough pins in the gasket have gotten very hot). Take off the oil cap and take a sniff. If it smells like burned wiring insulation, you probably have some burned/melted under-valvecover wiring harness connections. If all seems ok there, maybe remove the Injector Driver Module (IDM) from below the driver's side hood hinge and see if there may be water in it (shake it around to find out). Cheers!
 
#5 ·
Still no luck on my end. I did notice that one of the UVCH connectors was covered in oil. I pulled it, cleaned up the oil, but it still seems to be leaking. Would this be the cause of my issue? I did get it running for a bit today, but then, as before, the check engine light came on and the stutter started again. I did notice something this time around though, the alternator is getting very hot. Could this be the cause of my issue?
 
#6 ·
Ok, just figured mine out and repaired it this last weekend. My uvch connectors looked fine from the outside. I pulled the connectors and there was oil on one of the drivers side connectors. I took the valve cover off and where the wiring harness plugs into the cover gasket was just melted and fried to no end. Replaced the valve cover gasket and the one wiring harness that was melted and bam fixed runs like new.

Freakyjlh, I'd bet anything if you pulled the valve cover on the side that had oil on the connector you would find the same issue. bonus is I replaced the glow plugs while in there.

good luck...Pat F, thank you for the input
 
#7 ·
Ok, just figured mine out and repaired it this last weekend. My uvch connectors looked fine from the outside. I pulled the connectors and there was oil on one of the drivers side connectors. I took the valve cover off and where the wiring harness plugs into the cover gasket was just melted and fried to no end. Replaced the valve cover gasket and the one wiring harness that was melted and bam fixed runs like new.

Freakyjlh, I'd bet anything if you pulled the valve cover on the side that had oil on the connector you would find the same issue. bonus is I replaced the glow plugs while in there.

good luck...Pat F, thank you for the input
I think you have melted harnesses. They can look ok from the outside but be burnt up internally. You could tell if this was your issue by checking codes and doing a buzz test, but if you don't have a scanner then you will need to pull the valve covers. Look very closely at the outside terminals in each connector. If they look at all brown/burnt then they are probably toasted under the valve cover.
 
#10 ·
Good morning all. I'm new to this site, and I'm having the exact same issues, without the CEL. I will be looking into the UVCH, to see if this is my issue. I honestly hope that it is because I have been trying to figure this out for about a month now. I am really getting tire of throwing parts at it.
 
#12 ·
Good luck Bass. Go with Patrick Feeley's recommendations. The minute I pulled the oil cap and smelled it, I knew what was up. Pulling the valve covers is well worth the time and money. Your truck is eventually going to need the UVCH's replaced, so might as well do it now. For around a $100, well worth the cost. Replace the glow plugs while you are under there. Good luck!
 
#13 ·
Here is an upate on my situation. I pulled the valve covers and inspected the internal harnesses and the gasket plugs themselves. I didn't see anything that appeared burned. I tested the harnesses and they tested ok. I checked the plugs and everything tested ok. I have replaced the CPS, cleaned and replaced all the filters. Nothing seems to have helped the "miss". One thing has changed however. I have gone from 19 miles per gallon to 8. I am getting desperate here. If any one has any other suggestions, I am definitely open. I did try to scan for any codes. Unfortunately, the scanner I had only reads trouble code, and since my truck isn't throwing any codes, did no good. The only thing it did was cause my truck to stall when it reached a certain point in the reading process. I am gonna try a diagnostic tool later today. I will see where that takes me.
 
#15 ·
The particular scanner that I was using said to start the truck. Anyway,

Had the truck scanned again with a different scanner and ran a diagnostics sheck on it. Here are the the codes that I got:

P1111
P0476
P0472

Any suggestions on these codes?
Would this have anything to do with the issues that I have been having? I'm just about to the point of giving up. What good is a truck if you can't afford to drive it.
 
#16 ·
Those codes are related to the EBP sensor and EBPV valve. Issues with those will cause low power, but shouldn't cause a individual miss.

What's your truck doing, what year is it, how many miles, and what all have you tried?

Really you ought to run a injector buzz test and an cylinder balance test. This will tell you if it's a IDM or injector issue going on.
 
#17 ·
Sorry about the lack of info. My truck is a 97 F350 CC 4X4. It has 225k miles on it. As far as what it's doing. Well, I guess about 2 months ago it started to have a miss. I call it a miss because that's the best way I can describe it. It does this at highway speeds, but there is no pattern to it. It is completely irratic. When it does the miss, it puffs a black cloud of smoke out of the tail pipe.

I replaced the CPS and fuel filter. Cleaned the FPR screen. Checked for the burnt plastic or rubber smell in the valve covers, no smell present. Just to be sure, removed the valve covers and looked at the internal harnesses and the valve cover gaskets. Everything looked to be in good shape.

After putting the valve covers back on. When I started the truck, there was a hiss, whine, whistle, however you want to describe it, coming from the area of the turbo. This was not present present before. After driving it, it felt like I pulling a heavy load with the truck. The sound has gone away, but I feel like the drag is still there. My fuel mileage has dropped from 19mpg to about 8.

Scanned the truck. Got nothing. My truck has not thrown any codes for a while now. Ran a diagnostics check using the scanner and came up with the 3 codes that I mentioned earlier.

I don't have the capabilities to do the injector buzz test or the cylinder balance test. I guess those 2 tests will have to wait until I can find some one that can do the test at a reasonable price.

If anyone could help out a little with any of the issues, things to check, I would be very grateful.
 
#18 ·
The loud hissing sound coming from the turbo is more then likely a hung up EBPV. There is a flap built into the outlet of the exhaust side of the turbo. It's commonly called a "warmup" valve. It's used during cold temps to choke up the engine to get it warmed up quicker. They can gum up and get stuck causing a restriction and very low power.

Look at the turbo down pipe area of the turbo. If you look beneath it you will see a rod coming out of the turbo pedestal connecting to it. This is the actuator rod for the flap. try and take a pry bar and move the rod out towards the passenger side. It should move out then return in. If it seems tight and doesn't return then it's probably hanging up.

If this is the case try and pry the rod back into the pedestal, this will open the valve up. Then disconnect the EBPV actuator solenoid. This is the 2 wire connector on the front of the turbo pedestal. This will keep the PCM from operating the EBPV valve anymore.

Normally I diagnose this by watching EBP readings. A really high EBP sensor reading tells you that the exhaust is choked up. Normal EBP sensor reading will be 14-15 psi KOEO and no more the 32 psi during engine running conditions.

I've never felt a screwed up EBPV feel like a miss though so sounds like you might have 2 issues going on..... A choked up EBPV will cause really low power and reduced fuel mileage though.
 
#23 ·
I did check my fuel pressure shortly after all this started. If I remember correctly, it was running around 50-55 psi. At that time, I did have a mod in place. I believe it's called the 10k mod (trick to boost fuel pressure). I have since removed the mod and the problem still remains, the truck just isn't as responsive as it was with it.
 
#24 ·
10k mod is it the idm which boosts HPOP pressure nothing to do with fuel pressure. the BB mod is what will boost the fuel pressure by placing a BB in the spring of the fuel pressure regulator. 50-55 at idle is ok, when you feel the truck stutter is the pressure dropping or going crazy?
 
#26 ·
Just an update. Here lately the "miss", hiccup, whatever we want to call it, has not been happening as often. Then, yesterday, it started back again, just as frequently as before. Finally took some ones advise and called the ford house and had them check for recalls. My truck has an open recall for the CPS and the speed control. I just recently replaced the CPS, but not with the ford one. Got the off brand from O'Riellys. And since I've been hearing so much about making sure to use the ford product, I was going to replace it again anyway. Have an appointment on Tuesday to have the recalls done. Hopefully this will correct the hiccup. Once that's done, I will concentrate on the EBP codes that I found. I will update again once I find out if it is the CPS. Thanks for all the input guys.
 
#30 ·
A boot refers to the rubber hose connections in the turbo system. Check those boots to make sure you don't have any cracks or cuts in them. It is usually best if you take them off, clean them up, and take a good look at them. Best CPS is from International, the Ford one is good also. You may also want to check your TPS (throttle position sensor). They have been known to go bad....I know a guy who has replaced his 3 times. Don't know how to check them, but the part is around $60.00. You used to have to buy the whole gas pedal assembly, but the sensor is now available by itself. Just some thoughts here, hope it helps.
 
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