StoogeMoe

My car recently started running rough, but only after a long drive. Once it gets in this condition it doesn't go away until the next day. Then the car runs fine.

I measured the exhaust header temperatures the one time and cylinder 1 was about 150 degrees cooler than the others. So I'm suspecting either fuel or spark acting up on #1.

Another clue is that the exhaust smelled "off" from normal. Maybe running rich? But I didn't see any black smoke coming out of the exhaust. And the spark plug on #1 looked normal.

So can an injector fail after they got hot and then recover? Or do they just die?

This is still early in tracking this problem down so I might have more clues later. Any ideas?

944Ross

I had a coil that did that. It only occured on long trips, and only when hot outside, and with the A/C on. On this car the A/C compressor was near the coil. After 350 - 400 miles it would start bucking and sometimes even die. At which point I'd open the hood to check things out, and it would re-start within 2 minutes (because it cooled off). Replaced the coil and relocated it, never happened again.

Wouldn't explain your #1 seeming to run cooler, tho.

V2Rocket

Yup, I had an injector intermittently go out. Sent them off to Witchhunter - DOA, no charge for that one.

F18Rep

Me too, and I could get the bad one to trigger at (least sometimes) with a battery.

I have a customer set of 3 injectors, make offer....;] ...Bruce

StoogeMoe

These probably are the original injectors. I had them cleaned by Witchhunter about six years ago. Maybe their life is at an end.

Thanks F18, but I have another spare set. Maybe I'll send them off to the witches and start using them.

I made it into work today with no problem. Let's see if I make it home.

peanut

I'd be inclined to change the spark plug and possibly the lead to #1 first before jumping to conclusions.

Might be worth doing a compression check whilst you are at it to rule out valve trouble in #1.

Have you listened to all the injectors with the engine running and compared ? you could use a screwdriver if you haven't a stethoscope ,might just have a sticky injector solenoid or blocked injector filter or pintle.

Its also possible that you may have a poor electrical connection at the injector. You could check the pulse with a Noid light

mfyoung1086

I would be surprised to see a injector overheat on a stock tune, but its not something I would say is impossible

best thing to do would to heat the motor up to cause the rough condition and check the pulse like Peanut said

If your running an aftermarket tune, I have experienced injectors overheating and failing, but this was on my 98 Saab... I thought I would be ok lengthing the injector pulse duration 30% percent to tune for E85, my injectors had different feelings about that

In reality they were prob maxed on the pump gas tune anyways

StoogeMoe

Unfortunately, it takes more than just warming the engine up to make it happen. I have to drive at least 50 miles. But it did happen on the way home from work on Friday night. Luckily it was only a couple miles from home. So when I pulled into the garage, I quickly tried various things like wiggling injector wires and the like. Then I changed out the #1 spark plug wire. The problem went away! So it looks like Peanut wins the early award.

I won't know until I drive it 50 miles again, which probably won't be until Wednesday. Fingers crossed

peanut

Thats great ! ....never mind the award ...just send lots of money to me at No46 Maple Drive, Hammersmith ...................

Glad to hear the car is running well again...