Hey guys,

I have some issues with a truck I just purchased. This is my 3rd 7.3 powerstroke so I am pretty familiar with them, and this one is giving me some issues! Just want to hear your thoughts before I start spending more money.

The truck is a 1997 F250 7.3 powerstroke supercab, Auto, 4x4. 205k miles.

I bought the truck last week with the issue thinking it was a simple fix, hopefully it is.

Here is the problem:

During acceleration at about 40-50% throttle or more the truck stumble/misses/shakes/bucks back and forth. This problem is amplified when the converter is locked. This happens loaded and unloaded.
The rpm range is off idle to about 2800rpm. Above 2800rpm it smooths out.

THIS PROBLEM ONLY OCCURS AT OPERATING TEMPERATURE!!

If I start it in the morning when it is 40 degrees and let it idle for a few minutes the problem does not exsist and the truck is fine until it get up to temperature a few minutes later!

The truck idles smooth and starts up great!

The truck doesn't leak any fuel or oil, and doesn't have any abnormal smoking issues.

Since the problem I have changed the air and fuel filter. I installed a new glow plug relay and 2 new batteries to get ready for winter.

Last night I installed a straight pipe and I can clearly here it missing through the exhaust while under full throttle.

My next step is to bring the truck to the Ford dealer where my buddy works to have it scanned.

Let me know what you guys think!

Thanks,

Tim

 

Do you have an IPR you can swap in?
If the IPR is sticking, it could cause that issue.

Cleaning the fuel bowl and FPR screens might fix that up too.

You can also try unplugging the ICP sensor and see if it does it as well.

This is all I can think of to try out, for I am no expert.

 

I was going to say IPR orings

 

Sounds like an internal high pressure oil leak . Have the guy Scan ICP pressure & IPR dc% , Cold & hot .

It could also be an injector poppet issue as well , or simply a loose poppet screw

 

Come to think of it, the truck did work fine for one day. Here is what I did:

I changed the fuel filter and installed my TS 6 position chip that I had out of my other truck and the truck was perfect for an entire day!

Next morning I went to start it and found the batteries to be weak, so I replaced both of them and did the glow plug relay at the same time.

I took it for a ride and noticed the problem appeared again.


Also, if I am doing say 10mph and I smash the throttle, it downshifts into 1st gear and takes off! Turbo and exhaust scream and it hauls with no problems!

I am at a loss until I have it scanned.

 

Is the crankcase full ?...

 

Finaly found someone else with my issue. I have the exact same truck and problem and had it scanned live data @ the dealer and found a TPS low voltage.( forgot the code #) havent changed it yet but it makes sense. Let me know if you find something differant

 

THe OP said his problem is when warm only , I don't think the TPS is affected by temp

 

Crankcase is at the full mark. I've tried unplugging the IPR and all it did was throw a check engine light and shift harder.

I will double check in the morning to see if I'm 100% sure the problem doesn't exsist when it's cold. Maybe it does and it's just not as pronounced.


One time it was really bad and it was effecting the shift firmness, only happened once though.

 

****UPDATE****

Injector buzz test came back good and everything functioned as it should. There was a code in the computer, it was an IDM code, I forgot which one it was. My buddy said it was possibly the IDM going bad.

So I replaced the IDM with a brand new rebuilt unit and I still have the same problem!!!

I am going to put a multimeter on the TPS sensor and if that doesn't show anything I am going to burn this truck to the ground!!!!

Anymore ideas anyone??

Thanks!

 

Any ideas???

 

U9 DIAGNOSTIC TROUBLE CODE (DTC) P1316 INDICATES THAT CODES ARE STORED IN THE IDM
Possible causes:
Injector(s) or circuit(s)
Open or shorted IDM enable circuit
Open/short in EF circuit
Open/short in FDCS circuit
IDM relay
IDM powering circuits
IDM
PCM
Check for other codes.
Have you decided if this it operating temp only ?

 

New truck to you ... have you changed the oil yet?

Changed mine today @ a bit over 5K. It was running just overall crappy and bucking a bit. I purchased the oil / filter a few weeks ago but weather has been to cold until today to do the change. Now it runs like a top.

 

This is 100% only happening at operating temperature.
There were no other codes in the computer.

Yes this is a new truck to me, oil change sticker shows I have 2k more miles until oil change is due.
However, I didn't change the oil myself and have no
idea what oil was used.
Maybe the viscosity breaks down and is causing problems? Wrong oil?

 

Operating temp only points to an oil related problem . IPR O ring, injector O ring or a poppet issue . We need some HP oil pressure test s to help you

The IPR O ring is a very cheap test ...