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Discussion Starter · #1 · (Edited)
Hi everybody,

Thank you for taking the time to read through this.

Got a 95 F350 that sat outside in cold weather (up to -4) for two weeks. Plugged it in and fired it up when it was about 23 and it turned out the Diesel was still gelled up because it barely started, ran very rough and kept dying for the next hours.

Now, three weeks after it still has the following symptoms:
  • Slightly rough idle
  • Noticeable engine vibration in Neutral at about 1300 and slight vibration above that, sounds like a miss
  • Pulls fine in first and second gear but often vibrates under load in 3rd, 4th and 5th and seems a little low on power
  • Every now and then idle oscillates very slightly between 700-750
  • There is no noticeable smoke when moving, slight haze when idling
Here are videos of revving it and the idling it:

Neutral revs - YouTube
Idle - YouTube

So far I have done/checked the following:
  • engine oil is full
  • tank is full
  • ran Diesel 911 and injector cleaner through it, no difference
  • changed fuel filter, no difference
  • changed fuel pump, that made it better but didn't fix it
The fuel pick up screen has not been changed in 8 years according to PO. This would be my first guess, but why would it shake at idle and then seem fine in first and second?

Other than that I could see it being a bad injector. I unplugged each one of the 4 harness plugs and they all seemed to make the same difference but that's not a very good test, I'll admit.

Idle oscillation could also be the IPR but do the other symptoms fit?

This being a 95, I don't think I can just plug in an OBDII reader unfortunately.

Thank you for any good suggestions!
 

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I have a 95 also, mine is obdII it is a transition year more than likely if your truck has ever been to a dealer they probably, have activated the obdII port under the glove box. It would be best to have it scanned to see if there are any codes. If no codes first thing I would try is adding a bottle of 911 fuel additive that is for fuel that has already jelled or is jelled read bottle for how many ounces to add and put it in both tanks. You can pick it up at any truck stop, Walmart and most auto part stores when I was driving over the road I always, kept a bottle with me because, sometimes I was in -5 to -40 degree temps I only had mine jelled twice in 6 yrs with similar symptoms it is worth a try and it will not hurt anything. Also, in case you didn't know auto part stores cannot read your codes it has to be Powerstroke capable scantool the cheapest way to read them is with the Forscan app and a Bluetooth dongle to plug into your obdII port the app is a few bucks and the BT dongle is 20-30 bucks.
 

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Discussion Starter · #3 ·
I have a 95 also, mine is obdII it is a transition year more than likely if your truck has ever been to a dealer they probably, have activated the obdII port under the glove box. It would be best to have it scanned to see if there are any codes. If no codes first thing I would try is adding a bottle of 911 fuel additive that is for fuel that has already jelled or is jelled read bottle for how many ounces to add and put it in both tanks. You can pick it up at any truck stop, Walmart and most auto part stores when I was driving over the road I always, kept a bottle with me because, sometimes I was in -5 to -40 degree temps I only had mine jelled twice in 6 yrs with similar symptoms it is worth a try and it will not hurt anything. Also, in case you didn't know auto part stores cannot read your codes it has to be Powerstroke capable scantool the cheapest way to read them is with the Forscan app and a Bluetooth dongle to plug into your obdII port the app is a few bucks and the BT dongle is 20-30 bucks.
Thank you! I did run 911 through the day it happened and it currently is 50F so the Diesel is no longer gelled, but the symptoms persist. I'm gonna try an OBD2 dongle and hope that the PCM has been opened up. If it's still OBD1 Ill use another dongle and the software from Car Code OBD2 for Android™ Enhanced Data Manufactuer Specific Scan Tool, supposedly that one works for 95's.
 

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Okay! Once, you scan it let us know if there are any codes and what they are and we can go from there. I've learned over the years most driveability issues could also, point to UVCH (under valve cover harness) my last driveability problem (low on power) was the UVCH I unplugged the connector at the valve cover and it had oil inside the connector I sprayed brake-kleen inside connector plugged it back in and all was good. But, I still had to go ahead and replace them once oil penetrates inside it will continue to do so. It's worth a look it won't cost you anything to check.
 

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Discussion Starter · #5 ·
UPDATE

OBDII reader actually worked, someone must have opened my PCM.

First did a cylinder contribution test and got P0263 Cylinder #1 Contribution code. During the test you could tell that cyl. 1 is doing absolutely nothing because the engine lugged down only 7 times.

Then did an injector buzz test. You can hear that injector 1 is way quieter than all the other ones. Got P1271-P1278 Codes for Cylinder #1 - #8 High to Low Side Fault, not sure if that's accurate??

Ohmed out the 42 pin connector and Injectors 2-8 are at 3.8 (little high but consistent) while #1 is at infinite.

Your opinions? Whats up with all those P1271-P1278 codes?

I am surprised that #1 shows infinite resistance but can still be heard on the buzz test, then again those do get high voltage.

My approach would be to first ohm out the injectors at the uvch plug to determine whether the problem is outside or inside the valve covers. Just need to figure out which wire at the plug is the one for the #1 connector.

If it's inside, it can only be the injector or the uvch, if it's outside, it's gonna be the absolute mess of a wiring harness that the po left me.

Thanks again for any good suggestions.
 

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'02 7.3L Excursion 3.73 Warn Hubs AutoTranny
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UPDATE


Ohmed out the 42 pin connector and Injectors 2-8 are at 3.8 (little high but consistent) while #1 is at infinite.
That means that the Glow Plug is burned out, or more likely the wiring harness is broken somewhere. Which can be under the Valve cover, or outside the Valve cover.

Pull the rubber plug loose on the #1 side of the engine, and Ohm out the glow plugs from the Connector pins. If it is Infinite there, you have Isolated the rest of the wiring to the truck as 'okay'

IF, the Glow Plug reads some ohm value at the connector, then the harness or Glow Plug controller is bad.
 

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Discussion Starter · #7 ·
UPDATE

turns out the injector was just disconnected under the valve cover because PO had broken both tabs off the UVCH plug. Weird how that happened the exact day it gelled up.

I just put a zip tie around it inbetween the blue and yellow wire so it cant slip off. Do you folks think that will last?
Motor vehicle Automotive fuel system Car Gas Auto part


Thank you.
 

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Glad you got it figured out obviously, it would be better to replace the UVCH but, as a temp fix that will probably hold for awhile and who knows it may last the life of truck.
 

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Glad you got it figured out obviously, it would be better to replace the UVCH but, as a temp fix that will probably hold for awhile and who knows it may last the life of truck.
Murphy's law is that if you purchase a new UVCH and plan to change it out when it fails it will last forever. If you just let it go without purchasing a new harness then it will fail at the worst of times.

Been there done that.
 
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I agree, probably 10 yrs ago I did the same as the OP it was during the winter time that I did the zip tie thing on mine to get me through the winter to warmer weather then I went ahead and replaced both UVCH's. Now that I keep a new set of UVCH's I will probably, never have to replace them again. Lol
 

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Just a note to the OP (and others that may care), the UVCHs with the plastic tabs are the "old" style (which also had seals for the plug). The "newer" style has bale-style wire clips and do not use a seal as they are not needed (the old seals won't fit anyway). Cheers!
 

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Hi everybody,

Thank you for taking the time to read through this.

Got a 95 F350 that sat outside in cold weather (up to -4) for two weeks. Plugged it in and fired it up when it was about 23 and it turned out the Diesel was still gelled up because it barely started, ran very rough and kept dying for the next hours.

Now, three weeks after it still has the following symptoms:
  • Slightly rough idle
  • Noticeable engine vibration in Neutral at about 1300 and slight vibration above that, sounds like a miss
  • Pulls fine in first and second gear but often vibrates under load in 3rd, 4th and 5th and seems a little low on power
  • Every now and then idle oscillates very slightly between 700-750
  • There is no noticeable smoke when moving, slight haze when idling
Here are videos of revving it and the idling it:

Neutral revs - YouTube
Idle - YouTube

So far I have done/checked the following:
  • engine oil is full
  • tank is full
  • ran Diesel 911 and injector cleaner through it, no difference
  • changed fuel filter, no difference
  • changed fuel pump, that made it better but didn't fix it
The fuel pick up screen has not been changed in 8 years according to PO. This would be my first guess, but why would it shake at idle and then seem fine in first and second?

Other than that I could see it being a bad injector. I unplugged each one of the 4 harness plugs and they all seemed to make the same difference but that's not a very good test, I'll admit.

Idle oscillation could also be the IPR but do the other symptoms fit?



This being a 95, I don't think I can just plug in an OBDII reader unfortunately.

Thank you for any good suggestions!
is it still very cold? fuel Jelled?
 
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