2000 grand prix with 3.1 engine


We have had this vehicle little over a month. Didn’t have any problems to begin with but now we are starting to. Care has almost 200,000 miles on it, our guess is that the car had never been maintainenced correctly. There was hardly in transmission fluid in it. Anyway the car was being driven 7 miles to work and then home again after an 8 hour shift so the old owner probably didn’t know that it was about to die. We drive 30 miels one way to work. After about a week of driving the car wouldn’t start after we turned it off. Finally got it home again and it sits in the driveway you can start it but once it got hot it would chug and then stall out couldn’t get it restarted. We replaced the crank shaft position sensor, ECM, had the iginition control module check, is fine, and checked the injectors. Yesterday after checking the injectors and fixing a broken wire it ran a little longer. After it died yesterday we finally got a code that stated “35” which is idle control circuit??? Where do we go now? This is our to work and home vehicle so we really need it run any suggestions???


sorry not a 2000 it is a 1990!!!


Is it safe to assume that a mechanic is out of the question? Is there a rhyme & reason to the parts that you are changing? Or are you just sort of making guesses?

Maybe start by having a repair manual on hand. You can get them for about $20 at an auto parts store. They don’t help with everything, but they surely do help.

Figure out which kind of thing you need to worry about. When it stalls and/or won’t start is it because you are losing fuel or spark? The CKPS & ignition module seem to be about chasing spark. But then you’re on about the fuel injectors. And I’m not sure what the ECM thing was meant to address. Either way, figure out which it is and concentrate there. If you’ve looked at & tested a bunch of stuff then you should detail that for people.

Has the fuel pressure been checked? Did anyone pull the spark plugs & have a look at what condition they are in? How old is the fuel filter? Air filter?

Whatever you do, don’t spend any more money on this thing without really knowing the problem/s.


We do have a manual. There is spark and there is fuel. My husband checked all of that. The reason we checked the injectors is because he saw a wire that looked like it had been spliced and he wanted to make sure that it wasn’t shorting out, because the car once it got warmed up acted like it was losing fuel. The weird thing is yesterday after he got off of work we went outside to take a look at what other grimlin might show up and the car acted just fine. We took it around the block and when he punched the gas it would start to chug again but not once did it die and then not restart. We changed the ECM because my husband was stumped and the parts store told him that the ECM could be the problem especially since the car is almost 20 years old. Checked the spark plugs, there is fire. Checked the air filter, it is clean. He now believes that the chugging upon acceleration is the throttle body position sensor. Is this accurate? Thanks for your input.


Well, checking a TPS is cheap and easy if you have an electrical meter. There’s no reason not to do it.

Is that spark strong and bright and blue? Make sure its not weak and yellow.

You say its getting fuel - that means a lot of things to different people. Some people just poke the pressure valve on the fuel rail and if fuel squirts out conclude that “there’s fuel.” So you really need to know two things - the first is whether fuel makes it to the rail at the right pressure. This requires a fuel pressure gauge. The second is whether the injectors are actually spraying any fuel into the cylinders. The surest way to learn about that is to pull the fuel rail & injectors. That can be a little complicated, so you can also just inspect the plugs after you’ve been trying to start it. If the fuel spray is healthy there should be signs on the plugs (and the cylinders should smell of raw fuel).

Before doing too much more work on it, I’d also check the compression. Air, fuel, and spark won’t do squat without that.