Bonneville SSEI stalling occasionally @ lights- while moving

[sgmburke]

Thanks for the assitance, and per advice, will start this new thread.

98 SSEI with 81k miles. Symptoms: occasional stalling when coasting to a stop. So far it has only happened when outside temperature is 40 degrees (may be coincidental). Idles very smoothly, and always starts back up quickly. Also excellent performance, no sputtering or mis-firing.

I will summarize what I found in various posts in terms of Stalling Bonneville possible causes:

1) Crankshaft Sensor (major effort getting the Harmonic Balancer off)
2) Idle Air Control (IAC) Valve
3) Fuel Pressure Regulator (FPR)
4) Ignition Control Module wiring harness (loose or corroded connectors)
5) MAF Sensor
6) Fuel Pump/Filter
7) Air Filter
8) PCV
9) Spark Plugs/wires
10) vacuum hoses

So considering both the probability of cause and degree of difficulty/ expense, and suggestions as to what to try first? Or potential things for this list?
-- Kevin

[Jfridge92]

I personally had a stalling issue with my car. It would stall the second I put it into gear, but would fire right back up in park and run smoothly until I got it into drive. My problem turned out to be the maf sensor. Usually the crank sensor is the main culprit other than the maf in issues like this.

[RJolly87]

What is the history on the car? How long have you owned it, and what has been serviced on the engine and when?

Also, have you checked to see if there are any trouble codes set?

[sgmburke]

I bought it from the original owners (Denver Colorado) in July 2014. Previous owners were a retired couple who bought it new, and had it serviced at dealers. They were not hands-on mechanics. Carfax shows regular maintence record from 1998 - 2014, with "recommended maintenance performed," but does not list details. I spoke to the owner, and they never experienced this stalling before. The only nagging problem they ever had was electrical dimming, but due to a bad on-star after market installation. They disconnected the on-star and problem went away.

No codes for this come and go problem. One thing I noticed at first look is that the vacuum tubing connected to the Fuel Pressure Regulator are hard and brittle. Defined will be replacing them, and looking at this source on eBay for 84.00: http://www.ebay.com/itm/380875680074?_t ... EBIDX%3AIT

I have a trusted mechanic who took care of my 1992 Bonny back in the 90s who I can trust to install things to a professional standard, and also not rip me off. So, in terms of troubleshooting measures, I am game to replace multiple parts at once as a prudent measure to not only fix this stalling problem, but prevent others. I am sure the original owners did the regular maintenance, but not likely they did any work not recommended by GM dealers.

Thanks in advance!

--Kevin

[96 SSEi]

I would start with the easy stuff: check maf sensor - first unplug it and see if issue changes, filters, pull plugs and see whats going on and a propane test for vacuum leaks, clean Iac. start with these easy things.

[MKMike]

In addition to the items you have already been advised to check.....
If you don't want to spend that much on vacuum tubing, you can buy the non-silicone tubing from RockAuto, etc, for far less.
To rule out the CPS, you can hook up a scan tool and see if the RPMs display when the engine is cranking.
If the display shows RPMs, then the CPS is not preventing the engine from starting.
Cheap enough to check the fuel pressure if you have a gauge. If not, many parts stores lend them for free.

[sgmburke]

MKMike,
Thanks. Can you provide a little more detail or a how to reference on this recommendation?:

==> "To rule out the CPS, you can hook up a scan tool and see if the RPMs display when the engine is cranking. If the display shows RPMs, then the CPS is not preventing the engine from starting."

[sgmburke]

Changed out three items, and the stalling is now RESOLVED:
1) New FPR
2) New set of Vacuum Lines
http://www.ebay.com/itm/380875680074?_t ... EBIDX%3AIT
3) New Crankshaft Sensor

Thanks for the help!

[AJT2004]

Glad to hear you resolved the problem. Another tip regarding troubleshooting a CPS; an easy check is watching your dash tachometer while cranking the engine. If it does not move while cranking the engine, the CPS may be suspect.

[SSEBonne4evr]

Probably was the crank sensor.