Hard starting on my 95 GTP

[oceancon]

Hi, the first start of the day is a bitch in my 3.4L, 95 GTP. Immediately dies after starting and have to keep pushing the throttle for about 5 minutes until it warms to get it to idle at all. There are no CEL's, it runs and idles good and also starts fine the rest of the day. Passed emissions as well. Strange, no?

all suggestions appreciated.

Joe

[gpse3400]

might want to check to see if your fuel pressure regulator is bleeding down.

[oceancon]

Ok, thanks. Is there a specific test for pressure bleed down?

[cedgtp24]

My car is doing the same thing. I go to start it after it sat overnight and the rpm hand goes all the way up to 3000 then it falls on its face. It doesnt stumble down then dies, it completely dies. I have to put my foot on the gas to keep it going for at least five min, then it will run rough until it warms up, then it runs fine for the rest of the day. I changed the fuel pressure regulator but it still does the same thing.

[oceancon]

Yeah, my mechanic changed the air temp sensor in the intake since it was giving a signal but that seemed to help only a little. i was thinking about the coolant temp sensor but this is hard to get to, being located under the exhaust crossover pipe! I was thinking about cleaning the maf or connections on that sensor. It is like a hit or miss thing especially since the car is not OBD II. Any other ideas?

[cedgtp24]

Yeah, my mechanic changed the air temp sensor in the intake since it was giving a signal but that seemed to help only a little. i was thinking about the coolant temp sensor but this is hard to get to, being located under the exhaust crossover pipe! I was thinking about cleaning the maf or connections on that sensor. It is like a hit or miss thing especially since the car is not OBD II. Any other ideas?

Im going to change mine this weekend. I am leaning toward this also since it only does this when cold. I am lead to belive that this sensor lets the computer know if the car is hot or cold, and if the car is cold and the computer thinks its warm then that would screw things up.

[oceancon]

GL with that, let me know if that works and if it is particularly a PIA !!

[gpse3400]

you need a fuel pressure gauge, you can buy or rent from the autozone or advance etc. basically if the pressure rises and doesnt hold you regulator may be bad causing a long start.

[the4biddendonut]

you need a fuel pressure gauge, you can buy or rent from the autozone or advance etc. basically if the pressure rises and doesnt hold you regulator may be bad causing a long start.

This is gonna sound stupid, but you can use a tire pressure gauge to check your fuel pressure if you want to save some money. On the other hand it is pretty ghetto.

[oceancon]

its not that its a long hard start since it fires up instantly. It just stalls and won't idle until I can get it warm. I'm thinking some other sensor, idle control, coolant temp sens, bad ground on PCM. It starts and runs great the rest of the day!

[heza]

possible intake manifold gasket leak? when engine is cold, metal contracts opening up gaps in the gaskets. when the engine warms up, the metal expands filling those gaps. common problem on all GM 60* motors.

[oceancon]

damn, I sure hope not. thats a PIA to fix as compared to a sensor - but I will have to keep it in mind as I go through different options - thanks for the info

[heza]

damn, I sure hope not. thats a PIA to fix as compared to a sensor - but I will have to keep it in mind as I go through different options - thanks for the info

...much rather, its much easier than on a pushrod or the handful of other things that can go wrong with the 3.4

[gpse3400]

This is gonna sound stupid, but you can use a tire pressure gauge to check your fuel pressure if you want to save some money. On the other hand it is pretty ghetto.

It's a thought...But I wouldn't unless I was drunkHEHE

[cedgtp24]

I thought that a bad lower or upper intake gasket would only give you a high idle when cold and it would correct itself when warm. I changed the temp sensor to the computer and mine still stalls when cold until it gets warm. When it does gets going, while still a little cool, the engine runs as if its flooding and i can smell a rich mixture coming from the exhaust along with a heavy putt putt of a missfire. Can bad coil packs or a bad ecm cause this to happen also? I pulled all the front spark plugs and no engine tone change came up but when I pulled the rear plugs it changed. My car only runs bad when cold you have to remember.