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90 Reatta starts when cold. Occasionally dies and then cranks and will not start when hot. There are not any error codes stored. Fuel pressure is OK when it will not start. Does not receive pulse to injectors when it will not start. I am considering replacing the crank position sensor. Read in GM manual that it could also be the ignition module. I could not get it to fail again to continue trouleshooting to further diagnose. Has anyone ever heard of a crank position sensor being intermittent? Any experiece with an ignition module causing the loss of injector pulses? If it is the ignition module, what are the thoughts on after market vs. delco. New delco is $175. OUCH

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Common problem on 3800 engines with over 100K . Usually the engine will run fine cold but will cut out when it gets hot. Obviously there could be many other factors that include module, ECM or mass air flow sensor.But usually the first place to start is the crank sensor they are known to fail

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crank sensor is only magnets. As far as I know magnets do not fail. If crank magnets move they get broken and you will have a no start all of the time. Maybe a bad connection at the plug in connector. I would suspect coil or ign module. $20 buck at my local take it off bone yard...........Ken

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I have been having same problem for months now and has graduated to include an intermittant miss as well. Use search function under my name for ideas. I have replaced control unit under coil twice using a Sorensen marketed by Advance - was not the problem and both did fine - $90.00.

Greg Ross, 2 Seater, Barney, and Easily have been helping me. Next to try is the crank sensor and/or ecm. I know what you are going thru - good luck. If I ever get it fixed I'll post ......

P.S. Search / History for intermittant starting/missing goes back to 06 19 02.

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kennyw, you are correct that the crank sensor is just a magnet and magnets don't fail .... but it also has wires attached to it and there is where it could (and does at times) fail as well as having the magnets come loose for various reasons. I have had the same type symptoms (starts easy when cold, won't when warm) and the problem has been the crank sensor. I would start with that and see what happens.

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  • 2 weeks later...

Problem was corrected by replacing the ignition module and the coil pack. Took the whole assembly off of a parts car of mine so it didn't cost me anything to try it. I've been working long days and haven't had time to get on here and update. Thanks for all of your input!

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Is a coil in the crank sensor (to convert the magnetic fluxes into an electrical signal that could fail though I have never seen one do it, more common is for the clamp to loosen allowing the magnets to come into ontact with the slots on the balancer and you get as physical failure. In that case the car won't start at all.

Cranks Sensor & cam sensor are low voltage devices and will trigger failure codes as will the primary side of the ESC. The secondary side (coils, plug wires, plugs) do not set codes. My personal feeling is that the "C" engine system with the square coilpacks is marginal at best, particularly with plugs gapped over .045" (I use RapidFires).

There is a six page troubleshooting proceedure in the 88 FSM on "cranks but does not fire". Is only way to be certain what is happening since at this point you do not know if problem is fuel or fire.

Initial injector pulse is independant of crank sensor. One of the steps in the chart is to artificially induce a set of injector pulses. If you do not get that and ESC has been replaced then I would be looking closely at the ECM. They do fail.

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