Last post on Mar 10, 2013 at 5:56 PM
You are in the Pontiac Bonneville
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Pontiac Bonneville, Auto Repair, Sedan
#100 of 233 Re: 3800 V6 intermittent starting problems [nikhit]
Apr 08, 2008 (9:48 pm)
I have a 1990 Pontiac Bonneville that is giving all the symptoms mentioned. It runs great but after it gets hot, it stops or will not restart. I give it a few hours and cranks right up like nothing ever happened. No codes on the computer or nothing. It took me awhile to figure out the fact that it could be heat related. But I replaced the fuel pump and filter. Still same problem.
Well I found this article that might explain the reason for this issue. It relates to the VSS (Vehicle Speed Sensor).
Check it out and see if it helps you:
I will look into it also and see if it fixes my problem.
#101 of 233 Re: 3800 V6 intermittent starting problems [neustkg]
Apr 09, 2008 (2:28 pm)
I have a 1997 Bonneville and your description, including your wife's episode, matches my symptoms. However I find that for about 1 to 2 hours after a FULL warm up, I can start the car, except on a cold day then it is shorter. Then it takes an hour or two to start again.
When starting the car after it is cold, I have noted that as it warms up, just before the thermostat is going to open, the car runs rough for about 10 to 15 seconds. Most of the time, if you are at speed on the freeway you might not notice it. If you are in a bank teller line, it can stall out. That's what happened to your wife. Her foot was probably not on the gas or she was just starting up. I have had the same failure on three occasions. Every time just as the car was getting to the open thermostat range.
I don't think it is the thermostat. I find the ground association to such precise timing to be unlikely, though I have cleaned my ground and no such luck. I have looked at the sensors on the car. I have had a heat issue with a crank shaft sensor and the sudden and total shutdown of the ignition system is unmistakable. Plus a CSS is timed to the heat up of the oil, not the coolant. Oh, no roughness either, just sudden failure, plain and simple. But the coollant sensor has no control over ignition or gas.
Once I get through the short rough seconds during the warm up, my car will run all day no issue. Again, a ground just would not run that way. It is nice to know that one of us has tried the fuel pump tradeout to no avail.
By the way, I have less trouble in warm weather (when the overall temperature of the car stays higher for a longer time) as opposed to cold weather.
Apr 11, 2008 (6:02 am)
There are several things people have found causing this. Some depends on the year and the mileage.
An ignition switch can have a bad contact for the spark system that makes and breaks while the contact for the other indicators like lights works fine. There is a way to test for the switch not making contact during a nostart period.
This switch is at the base of the steering column and is a fairly easy replacement.
People have found a poor contact at the ICS which is under the coils. Check the contacts on the connector plugging in there at the bottom end.
Crankshaft position sensor.
Cam position sensor.
#103 of 233 94 SSE Stall-out/no restart sometimes
Apr 13, 2008 (8:30 pm)
Apparently it has some error caused by years of Police Duty (Detectives car). It will intermittently stall out sometimes when this happens, it restarts immediately, other times it may not restart for hours. The Repair folks swore it was a Transmission error, and $1500 later it still does it. Another clue: Opening the doors, instead of triggering the inside lights, it makes clicking noises, the Security light comes on and off inconsistently keeping time with the clicking noise. Twisting the dashboard light control to 'dome' it quits clicking and the lights come on, the security goes out and it will start. I need this car as I am back in school for vocational rehab at Oregon State Unicersity, so no real income, family of six and no more $ for goose chases and towing to repair. If I hit the dash right after a stall it will sometimes restart and run the rest of the day.
#104 of 233 1993 bonneville start/runs/dies
May 01, 2008 (7:31 am)
ok, after a no spark condition. I replaced the cam and crank sensors, and the ignition module. now the car starts runs then dies after 3 or 4 seconds. Fuel pump? even thoght it was fine before the no spark started?
all grounds are good, cables are good, batterys good, fuses are good.
#105 of 233 Re: 1993 bonneville start/runs/dies [smokinjoe3]
May 01, 2008 (7:40 am)
You can try to verify the pump keeps running after it starts. When it quits, if you push on the schrader valve on the fuel line with a cloth/towel to catch the fuel (do this with a cold engine) is the still presssure?
the pump primes when you turn the key to ON for a couple seconds then turns off. After the car starts the oil pressure keeps a relay turned on to run the fuel pump. I don't know if there's another method that runs the pump while the motor cranks after the priming.
There may be a line coming up near the battery sticking out of a bundle of wires with a green connector on the end. I believe if you applied battery positive power to that it's supposed to run the fuel pump as a check on the pump for testing. You might see if you have that and if it runs the pump. You could connect it an try starting the car with it running that way to see if the pump is turning off after the initial prime.
#106 of 233 Re: 3800 V6 intermittent starting problems
May 02, 2008 (10:30 pm)
I have a 1997 Grand Prix GT with 105,000 miles on it that has the same problem of not wanting to crank when its warm. It turns over fine but wont fire. But after it cools down it will start up. I can hear the fuel pump prime, I thought about the ground wire connections but that doesnt make since it only does it when it's warm. The issue I'm leaning towards is the coil packs is it possible for them to overheat thus causing them not to work on a warm crank? Or a faulty control module? Any help on this would be nice TXS
#107 of 233 Re: 3800 V6 intermittent starting problems [waltjason]
May 03, 2008 (8:32 pm)
Well Walt, I thank that is entirely possible. I tried an experiment, I took two 6" fans
that Run on 12v DC, and rigged them to a termostatic switch set to 104(o) F. And wired so only when Engine in run position. So far, knocking on the Faux wood-grain on the Instrument panel, so good. A bit extreme, but I do know that certain Electronics are very sensitive to heat. Transistors and capacitors are even more so. Their efficiency drops of quite a bit once thetemperature reaches 100(o) F. There was originally white grease between the mounting plate and the bottom of the Coil packs. This grease helps in heat transfer and is used between computer chips and cooling fins in most computers since the P-II 233 MHz. It works. I noticed it had turned brown, so replaced that as well. Mechanics can never get it to duplicate, and get no error codes when it happens...
#108 of 233 Re: 3800 V6 intermittent starting problems [waltjason]
May 04, 2008 (4:53 am)
Carefully check you battery cables for corrosion. Turn off your automatic air and all with the key ON then remove key before checking. Reconnect the negative last.
Check the positive cable if there are two connectors one on top of the other between the connectors. Check down into the plastic for deterioration of the copper cable. Look at the other ends of the cables for good connections-retighten bolts if necessary.
Last I suggest checking for spark by removing one wire and laying it on a metal ground while someone cranks.
Then check for the injectors working by feeling them or putting a 194 running light bulb wires into the injector connector pins and you'll see the light flash.
#109 of 233 94 3800 V6 Bonneville battery losing charge
May 11, 2008 (11:10 am)
I drive a '94 Bonneville (mileage 157,000 approx). It was my mother's car and she gave it to us about three years ago. Overall it's been a good second car. We first starting experiencing problems with it over the winter. The brand new battery would lose its charge. Turned out that the power antenna had a short in it. We disabled it and things were fine for a while. However, the car has started dying again, usually at least twice a week if not more. Sometimes it'll happen during driving, other times it just won't start up again after having been driven a while. Usually a jump to the battery gets it going until it happens again. Husband checked the battery cables and they were fine. I printed out the posts re the ground bus which he's going to check now.
Everyone keeps telling us it's the alternator or battery, however both have been tested and were fine. Probably will bring to the mechanic soon, but would appreciate any help you could offer. We really want to keep this car as long as we can, but with two children we need something reliable. As it is, I'm afraid to drive it in case I get stranded (just happened again Thursday night).