2002 Pontiac Grand Am Hard Starting When Hot

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I have a 2002 Pontiac Grand Am with a 3.4 liter v6. When the car is cold it will start fairly quickly but when it reaches operating temp or sits in warm sun or high ambient temps it will turn over like mad but will not start.

Protech :
A check of the fuel pressure when hot would be a good thing to look at too. It should be in the range of 50psi with the key on and hold steady, not drop off. You can remove the vacuum line from the top of the fuel pressure regulator when the car is hot and look for a leak, even if you smell gas, and there is no fluid, I would still recommend replacing it.

Have checked the fuel pressure and it is fine no leaks detected, the temperature is the one constant in its starting or not, could it be a electronic solid state component causing this?

Usually not on the 3.4 engines, but anything is possible. If so, it would most likely be the crank sensor, or ignition module causing your issue, as they are the most affected by temperature.

Are they hard to find or get to? If it is fuel pressure does that mean replacing the fuel pump?

Not difficult to get at, the ignition module is under the coil pack on the rear of the engine and the crank sensor is down by the crank pulley. If the problem is fuel pressure, then yes the pump would need replaced. If you’ve got a clogged fuel filter, that can take out a pump too, so I’d recommend changing it as well. Did the problem start happening after that work was done?

Yes I already changed the fuel filter and plugs and wires engine only has 40000 miles on it. Where is the best place to get a fuel pump at a decent price I know they are expensive. No it was the reason for doing that work on it.

If your old fuel filter was really clogged, after replacing it is when there is usually a problem with the pump. It was used to pumping through a restriction and now that there is none, it’s volume and pressure drop off.  would always recommend a factory part, you will not have luck with an aftermarket fuel pump. Spend the money and get a GM part.

Can u get the electronic parts online? So if the pump was working too hard it loses its normal pressure? The filter was not badly clogged some water had settled in it.

I think you can probably find the parts online. And yes if the pump was working too hard for a long time it will usually go out or fail to produce optimum pressure and volume.

Okay I at least have somethings to work on and try, I really appreciate you help. Will a code scanner reveal any of these problems?

If there is a code set, then yes….otherwise you’d need a scanner that can actually watch live data to see if anything is glitching out.

What so you need to get a live scan?

On certain scanners, you actually watch the engine sensors working as the vehicle runs. You can see if there are any errors or mishaps as it’s happening. You could see if you’re losing cranking rpm, which would tell you that you have a bad crank sensor or module

Even if they only happen on start up?

Yes, that’s right.

I suppose only dealers have them.

You can buy one, but they aren’t cheap LOL

Heard that, what brand?

Well, it would be difficult to get one that we at the dealership use, but there are decent ones for sale at parts stores. I couldn’t say which brand might be best, I always use the one at the dealership LOL.

SO I take it they are not hand held devices?

Yes, they are.

Oh okay I have found a lot of them under 200 might try one.

Great, might not be a bad idea! Always a good investment.

Glad to help, have a great night!

You too !


1995 Pontiac Grand AM

It has a 3.1 liter. What is the sensor that goes on the rear cylinder head.

Where exactly are you talking about? There are a couple sensors back there.

The one that screws into the exhaust port.

OK, there is an Oxygen Sensor that screws into the top of the rear exhaust manifold, attached to the rear head.


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