New CPS fixed, now 4 days later same problem--???
 

Here's the skinny. 2000 SSEI: 122,xxx miles
Just replaced the CPS do to car cutting out like a switch while driving. Tech II said no signal from CPS once we go the car to quit while have the Tech II hooked up.
So new CPS installed, crank relearn, running good and back on the road.
Drove car for less then 150 miles and its back to cutting out again.
(towing bill getting up there)
I fired it up today after sitting for a day and took it up and down my long driveway. It hesitated one time and I headed back to my garage. Engine was at 210ish temp (normal operating temp)
Is there something else I should be looking at? I already checked the connections and such. Fuel Pressure was above 40PSI
Think the new CPS went bad already? I read the heat gun trick on the ICM but I havent tried that only because while the motor was cold we had no spark to all three coil packs.

Any thoughts anyone?

Usually when a CPS starts to fail, it will cut out but you can usually start the engine back up again. Did it do that before you replaced the CPS?

That was the exact problem before that lead me to the cps. Actually read from the tech II no crank signal. So replacing it fixed the problem. Only now it's back with the same anomaly. I would think the new part would last longer then 4 days.

210 seems a bit high for a 3800 with a stock 195 thermostat. I'm wondering if the high engine temps seem to be having an effect somewhere.

What is the hottest you have seen the engine temps get to?
With my 96' 3800 II NA I have a 195F thermostat, and normal operating temperatures vary for me, it depends on the ambient temps, as well as whether or not I am using the AC, normally I am from 180-190F when it is not too hot out, when it gets up to 90F or above, and I use the AC, I have seen 210-215F, this is pretty normal considering the primary fan turn on is set to 212F I think it is, and secondary should be around 226F, unless AC is on, and reaches a PSI higher that 190 PSI.
I am pretty sure the 2000's and up with 3800 II's have a tad higher fan turn on temps.

If the car stays at 210F or higher all of the time then I'd be a bit concerned, but even then depending on a few variables it could be normal.
I just looked over a chart of temps a buddy took when he had his 97' Firebird, and in an hour the temps went from 221F at the start, to 208F throughout most of the trip, he lives in a hot location though, and I believe the RWD 3800's coolant systems were around 18 PSI instead of 15PSI..


I wonder if his ICM is faulting from heat-soak?


NOTE: Forgot to mention I drilled a 5/32" hole in the top of my thermostat to assist with bleeding the system when maintaining it, so I am sure that little constant flow keeps me a few degrees cooler than normal.

Okay, maybe my 210° guesstimate is a bit off by a few degrees.
The normal operating temp is around the 200 grad mark of the temp gage, (middle) always has and never goes over that wither running a/c or not.
I'm pretty sure the engine temp is not an issue.

icm. try the heat gun if you have one.could be connector issue too

Already verified connector. Will try heat gun trick tonight I guess.

Sounds about right, your engine temps are fine.

I would hate to think a new CPS would fail after 4 days, even though the symptoms lead you in that direction. Here is a procedure for testing the ignition control module:

Part 1 -GM 3.8L Ignition Module Test and Crank Sensor Test (3X, 18X)

If the ICM checks out, the same article contains instructions on how to test the CPS.

Please share your results.