Could someone tell me where the coolant sensor is located on our '92 Bonnie? Thanks.

Which one? There are three.

Coolant temp for the gauge. Lower intake manifold
Coolant temp for the PCM. Lower intake manifold
Coolant level for the DIC. In the face of the radiator facing the engine.

Oh, sorry ... am checking on this for hubby. In sifting through many posts here (very nice, by the way) for our problem, we thought this might be a possibility, but don't recall them saying "which" coolant sensor? If it helps, I'll briefly describe where we're at now with the car. It really doesn't want to start - cranks and cranks and cranks - sometimes it will start and run briefly, but idles VERY rough and rich (plugs are all black and sooty, and smells gassy). Usually it just wants to quit right away, though. We have checked for codes and get none. Hubby has done LOTS and LOTS to her already, and getting very frustrated. I can give more info. if you would like, but does this sound like a plausible direction to head in? And if so, would you know "which" coolant sensor the authors may have been referring to? Thank you so much!

For the PCM.

It'* possible that the coolant temp sensor could cause that, as can a couple of other things. Can you provide a list of what your husband has already done to it?

Boy, you guys are fast ... awesome! Anyway, I will tell you, to the best of my ability, what hubby has done to Bonnie so far. This all started about 3 weeks ago, when he went to leave work, and the car didn't want to start, as I described earlier. He finally got it to stay running (barely) and chugged his way home. Now when you try to start, it really doesn't want to, and if it does, it is VERY rough idling and gassy smelling. Sometimes black smoke from exhaust, and there have been a few backfires, too.

I will back up just a bit further to let you know that we had problems with her last October, where she would just quit out of the blue, as you were driving down the road ... turned out to be the crankshaft position sensor, which hubby replaced. The car had been running fine from then on. A little over a month ago, hubby replaced the spark plugs and air filter ... not really having any problems, but figured it should be done. And the car continued to run fine, until our latest fiasco I described. Since then, he has done the following:

- Replaced camshaft position sensor (at the time, a code 41 came up for us, which led
us to this) ... since then, no codes, but still not starting or running right
- Replaced timing chain and gears
- Replaced interrupter magnet
- Replaced ECM
- Checked connections and hoses

There are probably things I am not remembering here ... will check with hubby later today. Also, please know that during our episode with her last October, in addition to the crankshaft position sensor, he also replaced the ICM and coils, and the "donut" on the exhaust manifold. One more thing, not sure if it has any bearing on the problem, but we live in Wisconsin ... and has been VERY cold and snowy. Any help for my very unhappy hubby and car would be greatly appreciated! Thanks again.

How many miles are on the car?

Has the catalytic convertor or harmonic balancer ever been replaced?

126,000 miles on the car. We bought her last July (3rd owner). Not sure if the cat. converter or harmonic balancer have ever been replaced ... not by us, I am sure. From what I have been reading, I wondered possibly about the cat. converter, but not about the harmonic balancer?

When it does run, about how long does it run? Besides the coolant sensor, the MAF sensor can cause a similar problem. Does your husband have a meter to measure resistance? If so, you amy want to try pulling the coolant sensor, and then see if the resistance changes as the temperature does.

If and when it decides to start, it is very short lived. Maybe 3 minutes at the "most", and again, VERY, VERY rough when it is idling. Sometimes if you keep your foot on the gas pedal it will stay running (again, very rough), otherwise it just dies. Hubby hurt back at work today, so is not up for car business right now. But will show him what you have here. Oh, and yes, he does have a meter to measure resistance ... will check on the MAF when he is feeling better. Will post back to let you know progress. Thanks again.