93 sport, chugging/stumbling

[sqhurt]

Ok my 93 sport had finally gave me some trouble. Few weeks back it rained an would run lil sluggish but once warmed up would run fine. It has done this for the 2 years I have owned it. Well after that lil bit of rain we got it started to run like crap in idle an while driving. It stumbles an seems to lack power. So I went an changed the fuel filter, no difference after that. Put the fuel pressure gauge on it an reads 40 psi koeo it held pressure for a good five mins before relieving it. I then start it an pressure drops to 31,32 psi an stays right there, I toke the vacuum line off the fuel regulator an it jumps up to 40 psi an does not move. Oh I need to add before I done all this I took the maf off an the probes of it was covered in black stuff. so I toke it of an replaced it with another one i had laying around. Have tried three so far an 2 i know are good. but when hooked up an running you can unplug it with no noticeable change in idle. One more thing I tried pulling the codes an my check engine light an battery light stays on. The self test does not seem to work anymore. Is this more likely my ecu? It could use new plugs an wires but with my check engine light not flashing or blinking like it used to when I try to pull the codes it seems to be more then just plugs an wires.. Any help would be greatly appreciated... Thanks Sqhurt

 

[sqhurt]

Alright finally got it to read the codes, got 157 which is mass air flow below min voltage... and 542 fuel pump circuit opencm to motor!! Now what do i need to look for or do to fix the 542 code?

 

[MrShorty]

KOEO 542 or CM 542 or both? Does the fuel pump run? Basically you are looking for a bad/loose connection somewhere in the fuel pump circuit. If it's CM only, it's probably an intermittent break in the circuit that you may not be able to find until it gets bad enough to bother you consistently.

KOEO or CM 157? Did you plug the MAF back in after the cleaning? Any other sign of loose connection in the MAF wiring?

 

[sqhurt]

KOEO 542 or CM 542 or both? Does the fuel pump run? Basically you are looking for a bad/loose connection somewhere in the fuel pump circuit. If it's CM only, it's probably an intermittent break in the circuit that you may not be able to find until it gets bad enough to bother you consistently.

KOEO or CM 157? Did you plug the MAF back in after the cleaning? Any other sign of loose connection in the MAF wiring?

They was Koeo codes.. Not to sure what cm is,could you inform me if you dont mind me asking? Also I just got done changing plugs an she runs sooo much better now... But once I pulled back in after the lil test drive she died an wont start back up lmao.. gotta love these trucks.. So now im hoping it is just hoping its out of gas even though I have drove the truck on E where the needle is now with no problems. Well we will find out as soon as the g/f gets here with the other car so I can go get some petro..

 

[MrShorty]

Two types of codes are output during the KOEO test: KOEO codes (sometimes referred to as hard fault codes) and continuous memory (CM, stored codes, or soft fault codes). KOEO codes are faults that occurred during the test, CM codes are faults that occurred at some time during normal operation, and the code has been stored by the computer. I've tried to describe the difference better in my "notes on pulling EEC-IV codes" in the EEC-IV forum.

 

[sqhurt]

Two types of codes are output during the KOEO test: KOEO codes (sometimes referred to as hard fault codes) and continuous memory (CM, stored codes, or soft fault codes). KOEO codes are faults that occurred during the test, CM codes are faults that occurred at some time during normal operation, and the code has been stored by the computer. I've tried to describe the difference better in my "notes on pulling EEC-IV codes" in the EEC-IV forum.

K thanks. I believe I understand it now. But both codes where giving in the 2 set of codes.. got 111 which is pass on the first set

 

[MrShorty]

So those are CM codes, with a KOEO 111 pass code.

SOP when resolving codes is to resolve KOEO codes first, then KOER codes (I'm guessing at this point that you haven't attempted the KOER test, yet), then resolve CM codes. My advice at this point, then, would be to clear CM (so you can see what codes are current and eliminate any "old" codes), and run the KOER test.

 

[sqhurt]

So those are CM codes, with a KOEO 111 pass code.

SOP when resolving codes is to resolve KOEO codes first, then KOER codes (I'm guessing at this point that you haven't attempted the KOER test, yet), then resolve CM codes. My advice at this point, then, would be to clear CM (so you can see what codes are current and eliminate any "old" codes), and run the KOER test.

Well after changing the plugs yesterday she has been running like a champ..I also went an did the throttle cable mod an the tps mod an so far soo good.. Also I cleared all the codes yesterday once it started runnning better an as of today an driving yesterday/last night an some today there are no new codes an still running great.. Gotta love this site.. Thanks to all