Can anyone guess this?
Thread Starter
Registered User
Joined: Dec 2013
Posts: 17
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Can anyone guess this? Okay I replaced the optispark and fuel pump. I start the car it's runs fine then it will all the sudden run like crap. Missing, backfiring, stuttering. Then I drive it for a while and it will go back to normal. I have good fuel pressure. Have brand new fuel filter. I'm lost. Throwing p0300 p01441. Please help thanks guys!
Teching In
Joined: Feb 2013
Posts: 33
Likes: 0
From: N. Ky
If it runs fine at first and then gets bad, I'd say you have another problem. Sounds like two possible problems. 1st: your ICM is having issues once it gets hot. 2nd: coolant temp sensor (the one in the water pump); also runs OK cold, but is giving the ECM a false temp and that's a problem when the engine temp gets warmed up. You need a scanner hooked up to it so you can read those inputs while the car's running and warms up. Mine didn't throw a code for the temp sensor, but the scanner shows what the sensors are reading. Good luck.
Teching In
Joined: Feb 2013
Posts: 33
Likes: 0
From: N. Ky
You could have the ICM tested, but if it's only acting up hot it will test good. Electronics aren't always just dead, or alive. I work in electronics and we see a lot of the "I didn't think that could happen" situations. Things on their way out, but still pass test can make you pull your hair out; must be why I'm bald now. Personally I had problems with the temp sensor on my 93. It started out that it would run crappy from time to time, then it would die for what seemed to be no reason, then some hard start problems. Finally it was hard to start and died after 5 minutes of run time all the time.
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Staging Lane
Joined: Dec 2013
Posts: 59
Likes: 0
The temp sensor can throw a code and it can also not throw a code. You can ohm it out if you have a multimeter. http://shbox.com/1/4th_gen_tech2.html go about 1/4 of the way down the page and you'll see a table with the resistance vs temp. Just take both of the test leads and put one on each metal prong coming out of the sensor and use the table to compare. The resistance should reflect the temp of the water in your engine.