97 Riviera dying, no start, etc.

Hi Everyone,

I've been battling a stalling and no start condition on my 97 supercharged Buick Riviera. It's been to 2 dealers and 1 local mechanic for a total shop time of about 5 months. Here's the symptoms:

* When you start the car from a cold engine and get it to operating temp, if you turn the car off and the engine temp is allowed to drop to the 7th tick on the temp guage the car sometimes does not restart. It just cranks with no catch. If I wait until the temp drops below the 6th tick on the temp guage the car starts. This doesnt happen all the time. Maybe once out of every 20 attempts. The only thing that is not random is the fact that it is always at the 7th tick mark when it does this.

* If you are driving and floor the gas peddle when the engine temp is exactly at the 7th tick on the temp guage the car clunks and dies. It wont restart for about 5 minutes. Again it cranks fine, sometimes it sounds like one cylinder is firing but that's it. It has to be at the 7th tick, not the 6th or the 8th. This only happens sometimes though. I was however able to reproduce it 3 times in a row but now I can't.

* Sometimes when I am sitting at a red light the car will just stall. Sometimes the car catches itself, RPMs drop really low, and then it fires back up.

* I am throwing a P0336 Crank Shaft Position Sensor code (dealers and local mechanic said sensor is fine)

* This might also be part of it: Last summer my car would start shifting at randoms times. Felt like I was doing neutral drop ins. If I turned off the car and restarted it it would be fine. This hasnt done this for 8 months now
though.

Here's what I've done so far:

* Local mechanic replaced ignition coil

* I replaced sparkplugs and wires

* Both dealers and local mechanic all checked the crankshaft position sensor and said it is fine. They can't figure it out.

* It rained heavily this weekend and I did not drive my car. When I went to start it it just cranked and cranked and nothing. I pulled a sparkplug out and smelled gas. I put the sparkplug against the engine block and cranked the engine and the sparkplug wasn't arcing. I continued to crank and after about 30 seconds the car fired up and the pulled sparkplug started to spark.

Any ideas?

I had similar issues with my 95 Riv. For the no starting issue as well as the stalling I had to replace my PCM at local shop @$600 for that pop and all seemed well after that. 5500km later the rpm drop outs and missing started happening again and I am in the shop again this time replacing the EGR sensor/valve. The electronics in this car seem to be really sketchy. I will get the car back possibly tommorrow to see if the EGR was if fact the problem @ another $600.:swear:

Ya, my 97 sounds like that too, except it always right back up,sofar.
It seems temp related too but I get no light ( ever). Changed crank and temp sensor. This is first time I heard EGR could cause stall out. I'll be waiting to hear your result. Mick

Had the problem with stalling when slowing down and stopped, only when car is hot, but ......since going to the dealer and they said they need a code to read, IT HAS NOT HAPPENED of cause! Its a good thing but the problem is not solved. Its been at least 3 to 4 weeks now. The only thing that I have done different since the dealer was to put 93 oct. gas in the car all the time. Can this be related? I don't think so, but I'll see.

Here are some things I would recommend doing...DO THEM YOURSELF AND SAVE MONEY IF YOU CAN...
Some of these things may not seem even remotely related to your problem, but they are necessary for keeping your engine healthy and sometimes its a bunch of little things that cause the big problems...plus they are cheap things anyway...
Replace your PCV valve and charcole canister filter...they are the most commonly overlooked parts of a good tune-up... buy them at a pepboys, autozone, kragen, etc...makeshure you look at your charcole canister filter before you buy the replacement to be shure they look the same(usually looks like mesh or cotton).
Add some fuel system cleaner to your next tank of gas.
Check/clean battery terminals and grounding wires on engine block.
If your distributer has a cap and roter, replace them.
Use a timming light and check your timming(call a dealer and ask for proper setting)
Change air filter if you havent in a couple months.
^those are all the simple, cheap things you should do and see if they fix your problem, if not then you may need to continue to the following.

If you are having a spark issue(thats what is sounds like) check the power line to your distributer...*side note*When wires heat up, it can cause resistance, and in some cars, the wire that supplies power to the distributer is of the lowest gadge necessary and extra risistance can cause serious problems, but removing this wire and replacing it with a wire of the next gadge rating(slightly thicker), you can eliminate these problems*end side note* Try using some insulation on the existing wiring, if that doesnt solve the problem, then try using a wire of a thicker gadge.

If you have like 100k or more miles on the engine, you might want to replace the timing belt(or chain), tensioner, and pullies (this can cause Crank Shaft Position problems, you may need to have a shop do this for you)

I would bet that if you did all of these things I have mentioned, your problem will be a memory... and other that the possible issue with resistance of the dizzy power wire, all of these things are routine maintinance...