2000 Grand Prix GT 3.8l V6 No start

[Flava601]

Hey guys. I'm new to grand prix forums so, I hope I'm posting this in the right place. If I'm not please let me know. Anyway I been scratching my head bald all week long with my 2000 Grand Prix GT 3.8L V6. It quit on me last Monday morning. It starting jerking and sputtering and then went dead. After about an hour I finally got it back started enough to make it nearly home. Had to push it last block and a half. Later that day I went out and she started right up! At this time I went ahead and completed a project that I had planned (upper and lower therm bypass pipes). Upon completion she started right up like normal and I ran her and burped cooling system and allowed to cool overnight. Next morning she would'nt start at all. I had a trouble code read approx. 3 mos ago and said MAF sensor was faulty. So naturaly I started with this. I read on this site how to test it; disconnect battery, unplug MAF, reconnect battery and start car. I did this and she started right up! I then went and purchased a MAF sensor;($160) and then she would'nt start again! Today I disconnected the battery again and this time unplugged MAF sensor and IAC. Reconnected battery and let her sit for most of the day. I went out and tried it and she started right up again. I drove it around a few blocks with both sensors unplugged and only problem I had was high idling. I reconnected both sensors and she has'nt started since. Can anybody help me please!!? Thanks in advance.

[JoshsGTP]

Welcome, Ok what it sounds like to me is a crank position sensor. When you had the car running did the tac drop to 0 and did the car keep running?

[Flava601]

When you say TAC are you talking about the RPM gauge? Car would stay running until I shut it off for most part. However, last time I had it running tonight (sitting still) it started sputtering and going on like it did when it first happened. Also when it starts doing that there is a mixed in squeal-like belt slipping type of sound before it dies.

[JoshsGTP]

yes did the tachometer drop to 0 and did the car stay on?

[chev1988rolet]

when it doesnt turn on, you can check crank sensor by unplugging a spark plug wire and see if it sparks. if it doesnt then it should be crank sensor. another thing you can do when it dont start is trying to push down on the pedal when cranking to give it some air. If it turns on and stays on then it could be the idle control valve. Also check fuel pressure and check fuel regulator vaccum line for smell of gas on it.

[Flava601]

Okay went back out and tinkered with it some more. Gotta check the TAC if I can ever get it back started. I did remove IAC on yesterday and found it real sooty. I sprayed it down with some carb cleaner and brushed with a soft brush to try and remove some of the soot. I replaced it and still never got it back started until I left both IAC and MAF sensor unplugged (as described above). I will need someone to turn ignition for me to check spark from plugs right?

[Flava601]

Will try the spark plug thing when I get an extra hand. Bout to try and catch a couple of Z's right now. Been up all night. Thanks for the feedback guys. Later

[BillBoost37]

Pull a boot off at one of the coils. You will usually be able to hear the spark from in the car.

[matt5112]

when you clean the IAC you're supposed to clean the TB side as well as the IAC valve itself.

[chev1988rolet]

yea just like that but dont leave engine on too long cause it could damage your coil. turn engine off once you've verified there is spark. Also, check every tower on every coil cause mine use to whistle from belt when i changed my head gaskets and turned out to be a ruptured diaphram at fuel regulator and my 3/6 coil had no spark. fixed those and then purred like a kitten

[BillBoost37]

In checking for spark, we only need to check one coil.

Most likely the issue is MAF or wiring going into the MAF and not a spark issue. Being that he only needs to see if he has a spark, there's no reason to test all of the coils.

If that was the case, I'd suggest a cheap spark tester light that goes in line by the plugs.

[chev1988rolet]

oh, I would check spark at every tower only cause some ecm's dont set a dtc for a P0300 which could cause whistling at the belt. I dont know much about maf sensors or what kind of symptoms they bring. I thought just a rough idle but i have no idea since i've never came across one failing. just heard they do kind of often

[BillBoost37]

If he mentioned spitting and sputtering, then yes all coils, plugs and wires would be suspect. However with him mentioning that it runs good when it does..that puts us on a slightly different diagnosis path.

If spark is there, then it should be there for all. One or two coils causing a whistling sound on the belts is new to me, unless it's because it's so rough that the belt is bouncing like mad.

[chev1988rolet]

yea cause one coil out means engines running at only 60%. that an it caused mine to whistle but also it running rich cause regulator

[JoshsGTP]

yea cause one coil out means engines running at only 60%. that an it caused mine to whistle but also it running rich cause regulator

[chev1988rolet]

just giving some tips to help properly diagnose whats wrong cause it sucks throwing money at parts.

[QUICKSILVER462]

A very easy way to check for spark, is a timing light, if you have one. I just put it on a sparkplug lead, adn look for the light, of course it does just tell you that that current is traveling through the wire so it has to be sparking somewhere, lol
That way you can leave everything connected.

[Flava601]

Hey guys! thanks for all the info. I tried a lil of everything and still kept coming up with (sit for a few hours, disconnect battery, unplug MAF and IAC, reconnect battery, car start right up) same scenario. Been had a lot going on in last couple of weeks (since Fri. 13th, go figure) so I finally gave up and took it to Phillips Car Care and had it diagnosed. $239.00 later problem was found to be IGNITION CONTROL MODULE. Had it replaced and now purring like a kitten. My thing is now I just replaced that module approx. 6 mos. ago. I'm going to check into the warranty info on it in the morning. However, I did realize that I failed to apply the supplied THERMAL GREASE to back plate when I installed it which I assume could've contributed to its premature failure. Anyway like I said problem was ICM. I thank you all for the replies and help. I look forward to chatting witcha later!