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Pontiac Grand Prix Starting / Stalling Issues



  • To all those with the same problems:

    My 1999 Grand Prix has been acting up with all the same symptoms many people described. Engine cut out at highway or low speed; hard to start after a hot shut down; the Trac light stayed on after the engine cut out and immediate restart in neutral etc. It was getting worse lately with the hot weather. I contemplated replacing the crank position sensor, mass air flow sensor, PCM one at a time, and hundreds of $ at a time, like many people before me. Then, I found the way to fix my problem at ZERO DOLLAR!
    I figured that it could be a voltage problem. I used a multi-meter. I measured the voltage across my battery, which show the normal 12.7 V. But from the positive terminal junction to a good ground on the engine (e.g. Al engine mount) the voltage has dropped down. I also measure the conductivity as well, and I did not get zero Ohm between the negative terminal to the good ground spot on the engine. I removed the grounding cable attached to the body panel and found that it was bolted on to a part with original body paint! What a bad design! Paint is not the best conductor in the world! After years of dirt and rust build-up, the conduction between the bolt threads won't be as good as before. So you get intermittent voltage drops that stalled the engine. I gave the contact a good rubbing with sand paper. I check voltage and conductivity after and it was good as you would expect. Since than, I never had a single staling. It has been three weeks with lots of kilometers in hot weather.
    I trust that the same remedy will solve a lot of your problems. I apologize to many garages for reducing tens of thousands of dollars of their potential business.
  • Yup!

    I have a 2005 GP base model - I had similar issues. My engine did not die at hwy speeds BUT the computer would crash leaving me to fly a dead elephant down the hwy with no gas or instruments. There is a secret GM TSB I pasted it a while back for Chev, Pontiac and Buick cars running on the Impala platform. The first recommendation is to check the ground strap and the second procedure is to flash the PCM's with a firmware update (not your naked body - although you can try this for kicks). I did what you did and cleaned off the strap and have had no issues apart from a rough start after a hard drive which is likely an oxy sensor on its way out or a filter. Good on yah dude - that's a good fix. Sorry you had to spend so much money - but it sure feels good when you stop!
  • esoneesone Posts: 3
    Hello everyone. First off, thanks for taking the time to read my post.

    I have recently bought a 1998 Pontiac Grand Prix SE 3.1 for $600.
    When I purchased it, it had the Low Coolant light on, and check engine light on.
    I knew right off the go what the coolant light was. Damage to the intake manifold gasket due to the DexCool that was in the cooling system. I had that replaced. The Low Coolant light is still blinking, I'm thinking it is a bad sensor because I had also just replaced the radiator cap and upper hose, no further leaks are found in a pressure test. Oil was changed when intake was replaced as to get out all the coolant/water from the engine oil. This is not my main problem.

    The main problem is the car has a somewhat of a rough idle. More now than before.When you start the car (It starts fine by the way) the RPMs fluctuate from 500 RPM - 1000 RPM. It doesn't die out, but sounds sluggish. It is fine while moving, and when it slows back down to idle, it fluctuates only minorly.
    The Check Engine light I am getting is for a Camshaft Positioning Sensor.
    I know where it is, and how to change it. But, would this be the reason of why it is acting so strangely?
  • smv1smv1 Posts: 14
    Hello, well if you currently being advised that the camshaft positioning sensor needs replacing: this may solve your problem but if it continues then you will more than likely need to replace the crankshaft positioning sensor also since they both work in conjunction with each other. If you get a automotive manuel for this you will find and read about the " Hall Effect ".... Good Luck with your new toy! smv1
  • Hey all,

    I had my 2002 grand prix at a local mechanic with stalling issues. Sometimes it would start, and stalls near idle, but has also stalled while driving. He initially fixed some vacuum seal and that didn't do the trick. He replaced the crankshaft position sensor and that didn't work either. I took it to a dealership where they put in a new PCM and ignition control module, not a damn thing. The service engine light just came on (after all of this work) and it's reading P0300, multiple random misfires, and i have no idea what the problem is. It will start and run beautifully sometimes, other times it takes multiple attempts to stay running (will turn over, quickly die), and often it will run very rough and will "rev" for no reason. Anyone!?
  • I wrote earlier that I solved my problem (all the same symptoms) by just cleaning up the battery ground cable. It cost next to nothing if you or a friend can do that yourselves. Check for voltage drop or whether there is any resistance between the battery negative terminal and a good ground spot on the engine. I did not spend a single penny on replacing any of the components mentioned. It worked for me. It may not work in your case but it is worth a try. Please let us know the results if you do that.
  • I have a '99 Grand Prix GTP with about 65K on it. Car never had any problems until recently, and I'll explain: I purchased gas at a diff gas station than I normally do (I try to stay with one particular "brand"), got the premium as always, no issues. After getting home and trying to start the car back up again it kept sputtering when I accelerated, and died out when at a complete stop. The car will start back up again, no problem. If I get the car to maintain a certain speed (highway driving, for example) I have no issue with stalling or sputtering when accelerating. It seems to happen if I am: A) at a complete stop - it will sputter, jerk forward, then sometimes die out (not always though). B )if I am starting to accelerate after a stop/starting up the car will start to sputter. If I let it run idle the car will sputter, and the lights will dim as well with each sputter, as well as the RPM gauge moving up with each sputter. I have already changed my fuel filter, and I had added some Lucas fuel additive in case it was bad gas. Is that a possibility? I still have not run all of this gas out of my tank (I got a full tank) I also had taken the car to both Autozone and Advanced Auto Parts for the free diagnostic check and neither place showed my car as to having any codes to figure out what the problem could be. (also there is no Check Engine Light on). I don't have a lot of money (paycheck to paycheck living here lol), and since no codes/engine light are coming up then what could the issue be? Any help would be appreciated, thank you so much!!
  • I had similiar problems, car would start then stall, idle would bounce around. The problem is your fuel injectors and body is dirty and you need it professionally cleaned by a pontiac dealer. It's called a BJ Fuel inject and they take off the cover and clean all of the injectors and body. It costs about $100 but well worth the money as I immediatly saw a jump in my MPG's. Used to be around 19-20, now I'm around 23-25. The cleaning will pay for itself in no time. I made no other changes at the same time and this immediatly solved my problem. I did change the oil & filter, fuel filter, and air filter about a month after just to make sure my car had everything it needed to last. You have to remember that the oil is the blood of your car, the engine is the heart, the air filter your lungs, collant is your clothes to keep you at the correct temp, and the gas is your food (fuel). If any of these gets clogged up you are going to have problems. You should always check each of these things everytime you get an oil change done to make sure there is no problems (except fuel filter as that can wait 4 or more oil changes).
  • I've been there: I really hoped at first that my car's issue was that one day I had simply gotten gas at a cheapie place. $811 in repairs later, I'm sad to say that it wasn't.

    However, I'll also say: The guys at the garage NEVER had a problem with the car.

    For them, it always ran great.

    For me, it often refused to start or just died in the middle of traffic.

    The car runs fine now, but I feel some loss in power -- as if the V6 has gone down to a fully functioning 4-cylinder.
  • Hey Pat,

    thank you for your response. I did indeed try that fix. I used a wire brush to clean up the terminal, the screw, and the frame of the car where they all bolt together. I was initially encouraged because my car started quicker than I'm accustomed to, however it faded within minutes as the car stalled while idling. I spoke with the dealer again today who had been working on it. They test drove it last week with an Ignition Control Module (factory) from a spare engine they had in the shop and they said it never gave them a single problem. After installing my aftermarket part ("standard" brand) it didn't give me any problems after 3 short trips but sure enough, it stalled out again. This is the first time the CEL came on too, code P0300 (random multiple misfires), and the engine was oddly "revving" after a cold start, it would run rough too. They're going to put their ICM back in and let me test drive it for a few days, assuming it doesn't give them any problems. I'll keep my fingers crossed.
  • smv1smv1 Posts: 14
    If your friend believes that you are getting a fuel cut; then I would suggest that you check your fuel preasure with a gauge. the guage will cost $35.00 to $45.00. If you do have low preasure, I would estimate that a new fuel pump will be aprox - $300.00 ..... Good luck and please post your result's....Sergio.
  • Actually last night on my way home from work on the highway at 60MPH it decided to die out, I was able to get on the shoulder, kick it in neutral, and crank it back up with no problem. That was when my Check Engine Light FINALLY came on. A blessing in disguise! I took it to autozone, a code came up for bad/defective MAF sensor. The ACDelco MAF sensor is around 300, the Cordone brand is 150. Do I really need the ACDelco MAF sensor? I am also going to buy an air filter no worries there. But its double the price of the off-brand, and I know ACDelco is GM made but I don't really have that kind of money to spend right now and I need the car to run smoothly so I don't end up sh*tting bricks on the highway again LOL. By the way 05grandprix, I get 25 MPG right now, but then again I do a lot of highway driving (50+ miles daily). I had my oil changed in Sept, and I get it changed religiously along with checking coolant/power steering fluid levels etc. Ive had the car for 6 years and Ive put 15-20K on it, it's only been the last few months with my new job downtown that I've had to drive so much, but I would still change my oil and everything accordingly. Thank you for your advice everyone!!! I just need to know now if I really do need the ACDelco MAF sensor or if the off-brand is just as good due to $ issues. Thank you!
  • Oh I feel ya! My boyfriend is going to go ahead and install the MAF sensor (I dont have $ to go to a shop, you spending $811 makes me shudder!), but whenever he drove the car to "feel" the sputters/lurching it ran fine. It ran fine on the highway for him too. But as soon as I get behind the wheel....LOL
  • Hi Jesse,

    Too bad that what you did to the grounding cable did not fix your problem, My '99 Grand Prix GT was stalling up to 3 times per day until I cleaned and removed the paint from the grounding point. The stalling stopped immediately and I have driven over 8000 km (5000 miles) in one month since then (I have to drive into Detroit almost everyday for the past 4 weeks and desperately needed to have that problem fixed). Since I did not spend a penny on the fix, I bought an OBD-II analyser (on sale) with the money I saved so that I don't have to run to my friends to check for error or pending codes. By-the-way, there were never any codes tripped after the stalls.
    The key to see whether your grounding cable is a problem or whether you have fixed it properly, if it is, is to use a multi-meter to check for voltage drop or resistance that should not be there. A consummer grade digital multi-meter costs about $25. It is worth getting if you don't have one or can borrow one easily. You should confirm the engine, therefore all components such as PCM, sensors, etc. are seeing the full battery voltage. The unwanted resistance may be in a different part of the circuit. A multi-meter has many other usages too. Good luck!
  • smv1smv1 Posts: 14
    My daughter's car is a 1997 grand prix and I replaced the MAF sensor with the Cardone brand and it has worked out fine ....Good luck...Sergio.
  • The dealership replaced the Mass Airflow Sensor and I've been driving it for 2 days now without any stalling issues. Too bad it was after a PCM ($1000) and Ignition Contol Module ($400) and Crank Angle Sensor ($400). If you're having these same issues I'd certainly recommend taking a shot at the MAF yourself. It's very easy to get to and swaps out with a special screwdriver, the parts will be under $200.
  • olds409olds409 Posts: 22
    Can I swap the starter from 3.5 engine into a 3.8? :confuse:
  • I just picked up a 20004 Grand Prix GT.My question is.Is there suposed to be a 1sec delay before it cranks? :confuse:
  • Did you ever find the root of the problem with your Grand Prix? My girlfriend is having the same exact problem with hers and of course the shop can't find what is wrong because it is not doing it while they have it. What makes it more frustrating for me right now is that she is not near my location so i just can't go down and help her whenever I like. So your experience may help me more rapidly answer the problem in a shorter amount of time. Thank You.
  • So, I have a 97 Grand Prix GT. (my baby) and for the past couple weeks when it hits 110 degrees the RPM meter drops to 0 and makes the car die sometimes. I have no idea what to do. A friend suggested that it might be the ignition switch, but that doesn't seem right to me. Oh, and when the engine is hot the car wont start at all. it trys to, but just keeps turning over. Any help would be greatly appreciated. Thanks.
  • I had a mechanic replace the ignition switch and this cured the issues with the electrical. It even cured the fan problems where the fan would only work intermittantly on high.
  • smv1smv1 Posts: 14
    Hi , you might have both the crankshaft and camshaft sensor's checked to see if the " Hall Effect " is taking place. When these sensor's get hot then they stop working until the cool back down; this is an intermittent problem and sometimes hard to diagnose... Hope this helps.... Sergio.
  • smv1smv1 Posts: 14
    Hi again and you might want to read post #210 and the original post back in April ; sounds like maybe this person also was having problem's with the tach.....Sergio.
  • ive come to the conclusion that its the crankshaft position sensor. and i would like to do the work myself. what tools would i need to replace that? i know ill have to remove the harmonic balancer as well but i dont know what tools ill need. any info would be great. thanks.
  • Hi,

    I'm curious if you ever figured this out. I have a very similar problem after putting a new battery in my car (i.e. whole thing is dead after trying to start). suggestion I have is checking cabling to starter as it might be the culprit.
  • prochieprochie Posts: 11
    That's a great point! I originally mentioned way back with my '05 Grand Prix that the ground strap near the batter on the body of the car gets build-up and corrosion - but there is the opposite end of the cable - which I never checked but could also be a problem - especially on an older year.

    A Recap of What I Did:
    GM issued a TSB describing the problem for Buick, Pointiac, Chev. I cleaned off the terminal end and the car body where it bolts down. I also used some white silicone grease as the TSB suggested but went one step further and placed a washer that would "bite" down into the body to give it a better ground - the ground only appears to be coming from the bolt and its threading. I followed up with some rust-proofing paint to slow future corrosion.
  • remi2remi2 Posts: 2
    i have a 2003 pontiac 3800 . when u start it .it floods a little like a misfire.then after a while it runs fine . i have changed all the plugs wires ,/cam shaft sensor /,coil packs/,injectors./what else could cause it. i also put it on a machine it said misfire on #3 celinder I NEED HELP (PLEASE) THANKS
  • smv1smv1 Posts: 14
    Maybe you have a bad fuel injector; I would swap the # 3 with the # 1 and see if the issue sill occurs but now it will indicate misfire on the # 1.... Good luck Sergio.
  • smv1smv1 Posts: 14
    Hi... electrical problems are always difficult and I had a similar problem with my daughter's 1998 GP 3.8 Auto... My solution after studying the electrical diagrams; had to do with a bad terminal connection on top of the automatic transmission at the Safety Neutral Switch and if I remember correctly it was the Purple wire that goes from the starter to the Safety Neutral Switch... Also this my sound rather basar but this same color wire goes to the release switch in the glove box to open the trunk. If you attempt to open the trunk with this button and it doesn't work then trace it back to the Safety Neutral switch... The new electrical male part was purchased at Pep Boy's in a packet for under $5..... Good luck, hope this helps... Sergio.
  • og1gtpog1gtp Posts: 1
    u should try changing the ignition module, it's about $135 bucks. I had the same symptoms and after installing the ignition module my GTP stop stalling. I really hope it works out for u oh and that thing with ur car parked and only reaching 4k rpm is completely normal and its called rev limiter look it up.
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