QuestionQUESTION: Hi, i have a 2000 Pontiac Bonneville ssei (3800 series 2)with about 176000 miles i just bought around March this year. Its ran good until about a month ago. It keeps stalling on me while driving (at low rpms) and while at idle. Starts right back up. New: IAC, TPC, Crankshaft position sencer, and redone vacuum hoses. I do hear fuel pump kick on when key is turned to on. I've heard about the Maf, but people say if it was that, by disconnecting from the harnesses it will run better, didn't help. Cleaned throttle body. No signs of gas in vacuum hose on fuel pressure regulator. Ignition switch seams good (wiggled key while engine was running, didn't stall). All accessories stay on after stall. All the work has been done by me, i do know a good bit about cars, but this has me stumped. I would really appreciate any help.
ANSWER: Hi Brian:
what happens when this stalls out. does it spit sputer and cough then stall or is it like someone turned the key off? did the problem occure after these parts were replaced or wher they changed chasing the problem? did any of them make it better if your chasing the issue? can you induce the stall or is it very randon or is there a pattern at to when it happens EG engine run time or driving the same route or the same spped for a certain amount of time? Does it start right back up? My Guess is it's an ignition system issue Eg spark problem. It makes a difference is what it does when it stalls out as to which way to start looking either spark or fuel. Have you had the scanned for codes at one of the big box auto parts stores? I'll assume no service engine soon light has come on?
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QUESTION: I'm sorry about that, i tried looking for a way to edit my question after i sent it. It stalls as if i would turn the key off, at any speed, can go days with no problems. When it stalls it does it back to back every 4 minutes or so. Up hill, down hill, flat, don't matter. Like i said beforehand,does it when at low idle, but the other day it did stall while climbing a highway hill at 60mph.has stalled before i changed parts. Codes have came up for all the things i have replace (beforehand). Now its throwing Low EGR flow, but i don't think that would cause stall, maybe if it was stuck open, but i cleaned the ports on it, still stalls (didn't look bad any way). I'm really at lost here, this car is a beauty, but this one issue is putting me and my family closer to money issues every day, if its not for parts its for the gas i have to dump back into it... i'm praying i don't have to take it to a shop, i really cant afford that right now.
AnswerThe EGR code I doubt has naything to do with it. Low flow could be for a # of reasons the trnafer tube could be carboned up beween the valve and the in take if this engine is burning oil it will carbon up quickly. A few other things to check on this when the engine is running pull the vacuum line of the fuel pressure regulator and let the engine run for a couple of minutes there should be no raw fuel in the port on the top of the regulator if there is the regulator is bad. Another thing to check is the rear spark plug wires towards the fire wall make sure the wires are routed away from the engine harness If you need to use Nylon pul ties to do it then so be it. Stray EMI from the plug wires can induce voltage to the Post O2 sesnor reading and also for the VSS in the tranmission and the engine computer get a scrambled message and then it can induce a stall. As for low speed stalls did you clean the Idle air control calve pintel (cone) when you cleanded the throttle body? when you cleaned the throttle body did you take the MAF sensor out before hand? If not you could have gotten debris in the sensor I know you said you drove it with it unplugged BUT the MAF is right in the path of the throttle body and the cleaner can splash bad on to the sensor. Try cleaning that as well. Use a product called MAF sensor cleaner it's made by CRC and is in a red and black can. Hope that helps you out. Usually a crank senor 90% of the time fixes these for stalling issues.
