93 TA w 107k mi. The car starts and idles but once it reaches operating temp, starts hesitating and stumbling.

Is this signs of optispark failing?

Fwiw, I was going to replace the plugs and wires this weekend anyway

Tia

 

Not sure on a 93 but If it were a 94 to 97 I would look at o2's. not sure how the 93 system works though.

 

SES light on? Could also be the coolant temp sensor in the waterpump. Once it goes into closed loop when it is warmed up it will have issues if it is bad. Just troubleshot one with this issue less than a month ago.

 

^^^I agree

 

Have you checked if it was throwing any codes?

 

No SES lights and how do I check if its throwing codes?

 

I'm guessing any parts store would have a obd1 scanner... My neighbor manages one so ill stop by tomorrow.

 

http://www.fbodyspecs.com/viewtopic.php?f=11&t=111#p737

I guess this only works on the 93's

 

my car did that and it was the opti

 

I'll run out and check that right now


fwiw, the car starts and idles fine... once it reaches 160deg, it starts to hesitate every rpm above about 1200. I can also smell raw fuel

 

Things like the ICM, coil, opti, etc., are affected by prolonged exposure to heat, namely the ICM. I would suspect that before anything.

 

VinR1, call around town. Some parts stores can test ICMs. Some don't do it anymore.

 

The problem with bench-testing an ICM is that testing it at room temperature won't give any indication of how it works when it's hot. I ran into this problem several years ago...it tested fine but still failed when I put it back in. A replacement later and all is well.

 

I think they're less than $20 anyway, right?

 

um... dumb question... where is the DLC terminal?

 

Rock Auto lists options from $44-90.

It should be to the right of your right leg when you sit in the car, if DLC terminal is where you hook the scanner up to. It is to the left of the center console.

 

that is so cool... its own code scanner


here's what it showed

28 Transmission Range (TR) pressure switch assembly fault
32 Exhaust Gas Recirculation (EGR)
61 A/C system performance

does any of that help?

 

since I know the reason for all the codes thrown, I'm just going to space out the ICM/coil and try that for the afternoon... still continues, I'll start with a new ICM and replace the wires this weekend (I already have 'em)

 

Autozone tests the ICM, have them do it a bunch of times in a row, that way the internals warm up, they seem to fail when its hot. Also when the motor gets hot, it wouldn't be a bad idea to check and see if you have strong spark or a weak spark, blue spark is a strong spark and yellow is a weak spark, that would help you determine if it is in fact ignition related when its hot, and not some other problem.

Btw, do you have a cat converter?

 

Yes, 17yr old original cat is still there...

put in spacers and as soon as it hit 160deg, it started hesitating again...

my buddy manages an O'Reilly... I'll get him to test it this afternoon