early 99 rough idle

[dieselnut85]

i just bought an early 1999 f250 7.3 liter...when u let the truck idle it seems like it misses or has an erratic idle...if u first start it and dont touch the acceleration pedal it idles fine..if u riv it up then let it idle it starts missing or loping...runs fine if its rived up over 1100 rpms or so...can anybody help... Ive checked the icp sensor...if u unplug it..it idles worse so i dont think thats the problem...any input would be greatly helpful...thanks

[strokin_early_99]

Have you checked for any DTC's to see if there are any stored codes?

Does it matter if it is cold or warmed up?

Does it matter if it is in gear or without load?

[Dirk]

sounds like those AB injectors are having solenoid/armature issues.

But as said before, you need to run the codes.

[dieselnut85]

yes i have checkes for codes...it has a bunch of the that come up...p0750,p0755,p0734,p1754,p0231,p0603,p0478,p04 70,p1747,p0720,p0541....yea i know theres alot..some of them are about the transmission...but its a 6 speed and it works fine...there were 4 new injectors put in the truck b4 i baught it and all the other ones checkesd out fine..the truck does it worse if its warmed up...it only does it if it is not under a load..ya just bairly let out the clutch to take off and it smooths rite out....the truck still has stock exhaust and the factory air box..i have an edge evolution programmer for it....truck is still set on stock untill i pipe it and open up the airbox...thanks for the help.....

[Dirk]

P0750 Shift Solenoid 1 Malfunction
P0755 Shift Solenoid B Malfunction
P0734 Gear 4 Incorrect ratio
P1754 CCS (Solenoid) Circuit Malfunction
P0231 Fuel Pump Relay Driver Circuit Failure
P0603 Internal Control Module KAM Error
P0478 Exhaust Pressure Control Valve High Input
P0470 Exhaust Back Pressure Sensor Circuit Malfunction
P1747 EPC Solenoid Short Circuit
P0720 OSS Sensor Circuit Malfunction
P0541 Manifold Intake Air Heater


OK, you say it has an edge and a 6 speed. Pull the PCM out and give me the code. Also, put the PCM back in "stock" and remove the edge. See how it runs.

It sounds like you have the wrong pcm OR your edge is screwing the truck up. All the Auto trans codes and the AIH is leading me down that path. Your early 99 didn't have a AIH.

As of right now, only the P0231 is concerning me. If you are having fueling issues, the problems you are describing can be caused by that. But it is hard to tell with all the random codes.

[Quickhorse]

The codes need to be cleared and run the truck for a day then check for codes again. Alot of those are from doing the injectors. As Dirk said, you shouldn't have an AIH(air intake heater) plug on that truck. Make sure they used all AB injectors when they did the install as well. Depending on how long ago they did the injector replacement you could have air in the HPOP system and when it is passing over the ICP sensor you are getting that roughness. Hard to say at this point . . .

[Dirk]

I don't think that any of the codes are from the injectors\HPOP system. I think that the OP has the wrong tuning or wrong PCM for the truck.

The relay circuit code is the only odd one that is throwing me off.

[Quickhorse]

Originally Posted by Dirk

P0750 Shift Solenoid 1 Malfunction
P0755 Shift Solenoid B Malfunction
P0734 Gear 4 Incorrect ratio
P1754 CCS (Solenoid) Circuit Malfunction
P0231 Fuel Pump Relay Driver Circuit Failure
P0603 Internal Control Module KAM Error
P0478 Exhaust Pressure Control Valve High Input
P0470 Exhaust Back Pressure Sensor Circuit Malfunction
P1747 EPC Solenoid Short Circuit
P0720 OSS Sensor Circuit Malfunction
P0541 Manifold Intake Air Heater


OK, you say it has an edge and a 6 speed. Pull the PCM out and give me the code. Also, put the PCM back in "stock" and remove the edge. See how it runs.

It sounds like you have the wrong pcm OR your edge is screwing the truck up. All the Auto trans codes and the AIH is leading me down that path. Your early 99 didn't have a AIH.

As of right now, only the P0231 is concerning me. If you are having fueling issues, the problems you are describing can be caused by that. But it is hard to tell with all the random codes.

Originally Posted by Dirk

I don't think that any of the codes are from the injectors\HPOP system. I think that the OP has the wrong tuning or wrong PCM for the truck.

The relay circuit code is the only odd one that is throwing me off.

Well I know the 603 is from having the main injector harness apart while key on cranking (after doing injectors). The 478 is from the red vacuum line being unplugged off of boost bypass diaphragm and the 470 is from the EBPV being unplugged. I am thinking the other stuff is from having the wrong computer and it not knowing where stuff is. Probably a PMT1 . . .

[Dirk]

Originally Posted by Quickhorse

Well I know the 603 is from having the main injector harness apart while key on cranking (after doing injectors). The 478 is from the red vacuum line being unplugged off of boost bypass diaphragm and the 470 is from the EBPV being unplugged. I am thinking the other stuff is from having the wrong computer and it not knowing where stuff is. Probably a PMT1 . . .

The 0603 is a KAM error. 99.9% of the time that is due to the fact that a "tuner" of some sort is installed. Harness codes would be that of injector signal or when IDM codes show up.

the EBPV sensor codes can be a number of issues. Unplugged, completely removed, bad sensor, clogged manifold tube to the sensor, rusted out tube, ect....

[symbols]

Yea something odd is going on to have auto codes on a manual trans