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reatta dan 1991

cold idle issue

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Just bought a 1990 reatta convertible had it about 2 weeks. Absolutly love the car. but I am having a problem.it is ding when I first start the car if I don't give it Gass. Then from when the car is cold to when it is fully warm the car has a very rough idle and sometimes dies. But once warm has no issues. I have replace the ignition control model The crank sensor the idle air control valve and o2 sensor and no luck still rough idle when cold. Any suggestions

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You might have a bad temperature sensor. From what I've read, it is needed on a cold engine, but not after the engine has warmed up. If it has failed, it might be sending the wrong information to the ECM, I guess. It might be causing a rich mixture, hope that helps.

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That's a possibility but it feels like a miss fire. It shutters and stalls if it is not given Gass. And even then it is a 50/50 weather it's going to die

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This is similar to the thread from OZ. I'd monitor the fuel rail pressure first, it is more likely to cause problems when cold. Should be in the 30-50psi range. Can also energise the green connector for a second or two to bring pressure up and see if it stays up for a while. If it leaks down quickly the regulator diaphragm may be ruptured. If so check for fuel in the vaccuum line.

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just ran the diagnostic program and got no e codes only b codes so now I am even more confused how is it that there r no engine coded but it keeps dying

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what "B codes" are you getting? if i recall correctly, the oil pressure sensor (B-132) runs the fuel pump for a little bit upon start up. there are also some vacuum hoses involved (cruise control), but not sure if that would cause a idle problem.

 

cleaning the MAF sensor took care of an idle problem i had. also if the crank sensor isn't gapped properly or if the crankshaft (harmonic) balancer has any cracks in the rubber - front or back - will cause enough of a "wobble" to cause the crank sensor not to work properly... the crank sensor problem won't throw a code.

 

this is in addition to what has been said above by BikeMikey & Padgett. :)

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The harmonic balancer will not cause this problem. The inner member has the slots for the crank sensor, the outer member driven by the rubber is mounted on a bearing and will not wobble even with the rubber ripped out, it will only knock at idle. I have had failure on 2 different cars that knocked but ran just fine.

 

I have had idle problems, one was the ISC gummed up and needed cleaning. The other was surging and dying at idle, it was the MAF sensor..

Edited by TexasJohn55 (see edit history)

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And will bet you haven't checked the fuel rail pressure yet. Fuel pressure and secondary igntion do not set codes on these cars so must be checked with instrumentation.

Could look at BLM/Instantaneous and Pulse Width - low fuel pressure will max these trying to compensate.

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Could look at BLM/Instantaneous and Pulse Width - low fuel pressure will max these trying to compensate.

Good information to know when problems occur away from home. I'm always looking for new "side of the road" troubleshooting techniques. Would that be true in both open and closed loop or only in closed loop when the O2 sensor is giving feedback to the ECM?

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OK bc I have ordered the tool to test the pressure but today I replaced the fule pump regulator and the fule filter. I feel like it's running rich when I have the issue bc it stumbles then revs up dropps back down stumbbles and goes up again. This is when sitting.

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