Well im trying to get my truck running right and I am in need of some help. I pulled the codes and here is what I have....

KOEO: code 54

KOER: codes, 21, 24, 25, 34, and 41

I have looked them up and have a pretty good idea as to what they are stating. My question is, where do I go from here? I don't wanna start replacing one thing after another if I don't have to.

Thanks, Daniel

 

54- most likely faulty IAT sensor. 21-didn't run test with engine warmed up to operating temp. 24-IAT, 25-poss knock sensor. 34-worn egr pintle causing evp to read wrong. 41- poss vacuum leak (upper plenum gasket most likely source).

I would be concerned with code 54, and 41. Replace the IAT sensor(located just behind the distributor on the intake manifold), and spray carb cleaner around where the plenum bolts to the lower manifold to check for the vacuum leak. These two will cause running conditions. The rest, will just make the light come on and store codes. In 86, the system wasn't as sophisticated as it is now.

 

Code 41 is also an IAT code, why would you think vacuum leak? Code 21 is ECT code and the truck had been running quite a while before I did the test so I know it was warmed up.

 

The code chart from Ford says that 24 is also an IAT code and 41 is an O2 code indicating a lean condition, that's where the vacuum leak comes into play. 21 is an ECT code. Most of the time this code is because the engine is not warmed up and the code means the sensor voltage is low. Best thing to do is disconnect the battery for about ten minutes, then hook it back up and drive it. Then retest and see what codes come back. Some of those codes in memory could have been there for a while, and you'll be chasing ghosts.

 

Yea I had my lines crossed on the paper I had 24 and 41 mixed up. I already had the battery off to charge it up and the codes should have been cleared cause I pulled them right after I hooked the battery back up. I have checked the 5 volt REF and it checks out good. Someone on another forum suggested that I check the SIG RET from the sensors in question and see if they are getting good ground and not sending too much voltage back to the EEC. Also I have tested the resistance on the ECT and ACT and both are within specs.