Check Engine Light & rough, sluggish engine! '91

[Thinkster]

I had an intermittant problem where the check engine light would come on after the car would sit for either a few minutes or few hours after driving it. For example, I would drive 20 mins., stop at a store, come back to start up car and it would feel shakey, run rought and the Check Engine light would come on. Then after a few minutes, the light would go off and the car would run fine.
Now, the past few days, it has not given me a break and the light has been staying on and the car running rough. I can't drive it on the freeway like this. It seems like it's missing or not firing all the pistons or something. I think it's some sort of sensor or something electrical as it has cleared up by itself before.
I think the key is that there is some condition that exists while the car is cooling off after it has been driven, and then started up again. Like some kind of pressure build up or something expanding/contracting or ??
Anyone have any clues or know how I can determine which sensor is triggering the Engine Check Light?

[lordrashmi]

I am not really sure about those symptoms, but take it to AutoZone and they will read your engine codes. Get those and post them and it might give you a clue.

[Thinkster]

well my AutoZone said they don't do that anymore and to take it to a shop. I was however able to find the "poor man's" code puller by using the screw thing on the ECU then reading the flashing LED's. Anways, the code that flashes is '51' which supposedly means "Fuel Injector Circuit Open".
So that's what I'm dealing with. Guess I gotta check the fuel injectors?

[Robdog]

I have a 92 max, and lately it's been doing the same thing. I replaced my fuel filter first, and that helped for about a week, and now it's coming back on. I think it has to do with the fuel delivery, so you may be right about the injectors. I sure hope not, because new injectors are expensive. Let me know what you find out.

[Diablo_VT]

it could be rust that's getting into for fuel injectors and making it do that... my dad's 95 dodge dakota would do that.. and he put in new fuel injectors and fuel filter and it seemed to fix the problem....

[Caesar]

I have the same problem. My check engine light is on all the time and the car is running sluggish and surging when i step on the accelerator. Anyone know how to reset the check engine light? Do i need to take it to the dealer to reset the engine light or i could do it myself? Any help is appreciated.

[Thinkster]

You can reset the check engine light yourself, but that doesn't mean it will fix the problem. I reset mine, just to clear any other codes that might have been stored, then when the light came on again, I pulled the code to see what it said was triggering it. If you want to see what your code is, or to clear it, click here Please report what you find, as I'm curious if yours is the same thing.

[guser52]

Did anyone ever actually find out the exact reason that the original problem occured? I have a 91 maxima as well and it's doing the same thing. I know it isn't the fuel injectors (any of the 6) or the injector harness because those all just got replaced and did not fix the problem. Should I just give up and dump the car or continue to search for the problem at $60 an hour?

[Thinkster]

UPDATE:

The problem seems to be solved now. I found that cylinder 5 was not working (pulled spark plug wire and no difference). Checked compression in all cylinders and that was o.k. , Checked spark at each plug wire and each spark plug, also o.k. Which led me to believe that it wasn't getting fuel. Pulled intake manifold off and pulled fuel rail with injectors. Tested each injector (resistance and 12v pulse) and confirmed that #5 was bad and #4 was on it's way. So in my case, replacing (2) injectors and servicing the other (4), solved the problem. Of course I also did a lot of hose replacing, cleaning and spark plug replacement as well while I had the intake manifold off.