Hey guys, just started playing with my new AE scanner, very happy! The only codes were for an EBPS but that has since been replaced. No new codes.

My symptoms are as follows:

- Truck starts quickly but will romp cold or hot if I don't touch the accelerator
- Rough idle, bucks and shakes
- No noticeable smoke upon start up or running
- The truck will not move under its own power, press accelerator and nothing happens in drive. Will rev in neutral.

ICP reads 700 at idle
IPR % reads 14 at idle
TPS voltage moves between 0-5V when revving.

I will work on getting a data recording for you guys. Any suggestions would be appreciated.

 

just to provide a quick response.. sounds like air in the fuel. it cranks, it fires, and it runs really rough. as for reverse and drive gear… i'm not quite sure how to tackle that one. i know one thing, you'll have numerous responses by end of the day.
good luck man.

 

Thank you! I have checked for fuel restrictions and leaks but nothing yet.

 

wonder what it could be. cant wait to see what it is.

 

if it revs in reverse i don't think its the throttle assly.
does the truck eventually 'smooth out' ??
something else that may cause the rough running is a low oil level. you might want to check the HPOP reservoir too. level should be within an inch or so from the top cap.
the 'Under Valve Cover Harness' connectors sometimes wiggle themselves loose too. may want to give those a look too. make sure both sides are securely fastened and giving a positive connection under the Y piping…
*continuing to think*
some other guys on here really know numbers and where everything should be falling..

 

I forgot to mention what I have done to try and remedy the issue.

- oil changed to rotella with motorcraft filter- level is good
- HPOP level is good
- new air filter
- new IPR and ICP sensors
- lift pump died about two months ago, it is new
- tank dropped and screens cleaned
- new fuel filter
- UVCH done, 50 cent mod
- buzz test passed with flying colours. Very good sound from all injectors.

The idle does smooth out once the truck is at full operating temp, but only a little. The curious thing is that above 1k RPM it is smooth as a gas engine.

 

Check the Fuel Pressure both Static and under a Load.

 

I have heard that the FPR screen can cause issues, would these symptoms match up? If so, is there a good guide on how to do it?

 

Have you driven at least 50 miles since the oil was changed/topped? Do you have a chip or aftermarket programming on the PCM? What was the temperature when you started?


14% IPR with 700 PSI ICP is appropriate for a cold engine. Once it warms up to full temperature, your IPR should settle down to about 10% (plus or minus about 1%) and your ICP should read about 475-490 PSI at idle.


EBPS code, eh? With the Key On and Engine OFF, what does the MAP, EBP, and BARO say?


What happens if you unplug the ICP sensor and start the truck?


When looking at idle, you need:

• RPM
• Desired Engine RPM
• Injector Control Pressure
• Injector Control Pressure Duty Cycle % (this is IPR, and you don't want it jumping around)
• Fuel Injector Pulse Width
• Engine Oil Temperature

To have a hard look at what's going on with the drive in AE (after you've checked your transmission fluid), you can check and record:

• Shift Solenoids 1,2, and 3 (I think 3 is reverse)
• Transmission Range
• Torque Converter Clutch (modulated)
• Gear Command by Module
• Torque Converter Slip Actual
• Transfer Case Contact Plate A through D
• Transmission Temperature
• Idle Validation Switch

 

I have driven more than 50 miles on the fresh oil change, only in the last two days did it decide not to move at all, about 300km on the change. With a warm engine the IPR was still sitting around 13% ICP around 600.

When I put the truck into drive or reverse the engine starts to stumble, ICP jumps to 1200 IPR is 21.

KOEO- MAP: 14.9 -- EBP: 14.03 -- 4.61v BARO --

*running-- FIPW-- .28

** EBP code is now gone because i replaced the sensor


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EDIT:

• Shift Solenoids 1,2, and 3 (I think 3 is reverse)
• Transmission Range
• Torque Converter Clutch (modulated)
• Gear Command by Module
• Torque Converter Slip Actual
• Transfer Case Contact Plate A through D
• Transmission Temperature
• Idle Validation Switch
  
  None of these values appeared no matter what I did with the sampling rate except for tans temp.

------------

Idling trans temp: 3.5V
No desired engine RPM idling (checked sample rate and it was fine)

Very new to using AE, I apologize for my ignorance. Learning as fast as possible.

I am home now so i can run out and keep checking values for the night. Also, I have never had any chip or tune on the truck, nor did the other original owner. Ambient temp is 28C.

 

All this is great information. But, if you don't eliminate fuel pressure as a possible cause, your just chasing a Rabbit down a hole.

 

Sounds good, I'll track down a gauge and connectors tomorrow.

 

Sounds like what mine did when I had to change the trans. First time it just rev in drive then finely it moved. Tow days later, backed out of a space, then 1st gear only at slow speed, then nothing. No signs at all to that point. I hope I'm wrong for you.

 

While the fuel will address the idling issue, it won't address the transmission issue. That ICP is pretty high - that's why I asked about it. A stock truck will idle just below 500 PSI ICP (not high-idle). Something is up with the engine temperature, the programming, the high-idle, or the time allowed to warm up - but that's not the correct reading for a warm engine at low idle. That reading may be indicative of a root cause for loping.


Early '99 eh? Well... as an experiment, try using the model year 2000 for hooking up on your AE - to see if that works any better.

 

Trans was done a few months ago by a reputable shop.