ok straight to the problem at hand. read how to check for codes but the check engine light turns off right away once in the on posistion and the cooling fans kick on as well when in the on posistion. fans kick on with or with out having both A and B bridged together. so it wont flash me any code to look up. once car is started it idles high and low and when revved the car hesitates as if not getting the gas right away. car is a 5.0 FI TPI 5 speed. electronic control module, mass air flow sensor, iac, and tps have all been replaced recently do to stalling issues. those issues were fixed then out of no where the check engine light popped on while on freeway and you could feel the car bog down and when light went off you can feel the car change again. its wierd. when light comes on and you come to a stop the car can have a horrible idle where i have to keep revving to not stall. when taking off from a stop it takes like 5 seconds to actually speed up decently like its not getting gas spark or anything that well just enough to crawl from a stop. hope someone can help!!!

 

anyone have any ideas? is the ecm going out again?

 

let's look at the 3 things needed to run an engine

first, let's take a leap of faith and assume that the air is fine. If you weren't taking in air or exhausting it, then chances are it would happen all of the time.


next is fuel- have you replaced the fuel filter? If not, then do so. Next, have your fuel pressure tested.

If you had an ignition problem then it would probably show itself more often but then again, you did not discuss the frequency of the problem. It could be a broken insulator on a spark plug, bad wires, coil, rotor, cap etc etc.

But, again we don't know for how long the car runs well

it could also be a sensor such as an O2 sensor. As for replacing the MAF, I unplug the MAF and let the car run in speed density mode to verify if the maf is in fact bad. It sounds like you've tossed parts at it hoping to hit the culprit.

 

my vote is for bad EGR valve, mine would do the same thing. the dead give away is the poor acceleration and the CEL light coming on when your on the highway. the diphragm is either ripped or the pintle is clogged with car.

 

Are you jumping the terminals to check codes and THEN turning key on? You jump first, then turn key.

 

i have tried jumping A and B and i get nothing not even a light. all i get is the sound of my fans kicking on which have never done that before only when reaching the required temp.

as for how long, it has been awhile now. i can usually drive it for about 5 miles and then the check engine light will start flickering before the car starts misbehaving all together then the light becomes solid. sometimes the light will click off but i still get the throttle response problem and as mentioned before you can feel it while driving when it decides to act up and when it decides to play nice. as of right now the car will start no prob from a cold start but with abnormal idle and hesitation when given gas. i cant say it does that all the times for i drive my other TA in fear of having it stall in the middle of traffic which has happened and im sure some know its not fun.

parts were not thrown at it they were from educated guesses using this web site. each part fixed a problem the car was having with the over 220,000 miles on it and lastly leading to a wonderful replacement of the MAF sensor which had a broken wire.

i too was thinking maybe egr or the egr solenoid. but those fans coming on is bugging me and the not being able to check codes. ill have to see where the egr is on the car and take a look.

any reason why jumping the A and B isnt working for me and do the fans coming on in the on posistion help point towards the culprit????

 

You are jumping the two top right pins with a paper clip and THEN turn the key to on? If you are and get get a reading your ECM is dead.

 

yes i was jumping both A and B, the two top right pins and got nothing but my fans turning on.

what is the possibility that the ecm is fine and im just getting no reading from jumping the pins?

i remember when i first got the car and tried getting it timed they said they couldnt do it from plugging in scanner because it wasnt getting a reading of some sort but they were able to clear all the codes which didnt make sense at all.

 

I'm not much of a believer in bad ECM's. I see everyone jumping the gun to replace the ECM, and I never see any reasons for such other than "I can't think of anything else".

Setting timing has absolutely NOTHING to do with codes or the ALDL connector or the ECM, so I have no idea why any "shop" would try to get or clear codes when you asked for timing help.

This car have a MAP sensor? Only time I've ever seen an intermittent SES light while on the road in a 3rd gen it turned out to be a MAP sensor issue. I'm no expert here, but it's a $15 part to try.

 

please read all the posts before jumping to conclusions. his car is an 87 and has MAF and it was replaced. If you check a service manual a non responsive SES is bad ecm or the terminals are very corroded.

OP check and make sure you have the prom seated all the way in the ecm because that or some loose wire can cause a problem too.

 

ok i will take the cap and rotor off tomorrow and check the connectors on the ecm. are these known to go out fairly quick. it was just replaced a few months back.

my thing with the timing is i was told by the place i took it to is that they do the timing on cars with an OBD type with a scanner tool to time it right and my car they werent able to read with it for some reason but yet they were able to clear codes.

 

just a thought ,,did you check the fan relay switch..on the fire wall....next to the mater cylinder,,,one is the fuel relay ,one is the fan relay,the other is a starter relay,, an if your not getting any code from ecm ,mine went bad an showed no codes at all...... it might be bad,,i would also look at any in line fuses you have for your fans, but then it's just a thought, you can find in your manual where stuff is on your ride in the book.....

 

well it looks like i didnt fully have the paper clip in when connecting both the A and B terminal to get codes. i did get a code this time but it was a 12 which is all clear. so it looks like i will take a look at the egr now unless someone has any other ideas. still curious about those fans coming on though.

 

ok stupid me didnt read intructions on waiting for the code 12 to flash 3 times then it will flash a code. im getting a code 13 which is Oxygen sensor signal stays lean during warm engine cruise. so do i just replace oxygen sensor and hope thats it???

 

Quite frankly I would try it because the O2 sensor is like $20. I would also check to see if it is plugged in as well before buying the part.

 

ok replaced oxygen sensor and pulled cable off battery to reset codes. still wouldnt rev right and cel on so i checked codes again and it wouldnt give me anything. sucked it up and bought ecm and it seems to be the last fix needed. now i am having a problem with my seat belt light coming on when head lights are turned on and it goes off every time i hit the brakes LOL any ideas on that one??? oh and thanks for everyones help!!!!