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Car starts but stalls after 2 seconds

C

cartooz

New member
I have a 99 GT with a blown engine so I swapped the motor, wiring harness, all computers, steering column, dash, transmission. The engine will start but will not run longer than 5 seconds. Even if I give it some gas the motor will rev up but the engine still cuts out. I unlocked my stereo and turned off the antitheft.

Anyone have an idea of what I'm could be missing?
 


sounds like the pass key system isnt liking your key man. i would figure out a way to bypass that or have the dealer reprogram the system.
 
If I bend a pin on my fuel pump speed relay the car will continue idling but it's not a smooth idle.
 
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disconnect the idle control soleniod and see if anything changes. if it stays the same then thats it. if it gets worse then im wrong. also...tap on it and see if it works.
 


The only part that I haven't taken from a GTP is my fuel sending unit. I know that both the unit from the GT and GTP have the same pressure range (48-55psi), but the car will only maintain an idle if I bypass the resistor in the fuel pump speed relay, meaning that the fuel pump is on high speed. I don't know what this means or how to make it run correctly. On top of that my fuel tank gauge is way past the full line and I only have a quarter tank of gas???
 
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I tried using three other identical relays and I ended up with the same result each time.(car stalling out after 2 seconds). I thought that I had a bad resistor in the relay but that can't be the case. Once I readjust my tranny cable then I'll take it out for a ride to see if it's good to run or not. Either way I will switch my sending unit with the one in my wrecked GTP to see if that will make a difference.
 
why is it stalling. what is your fuel pressure doing...you never specified that this was a fuel problem or why you r leaning that way. test the fuel pressure first
 
I was thinking that it was a fuel pressure problem because the car would only maintain an idle with the pump on high speed. I will check my fuel pressure, I just need to find someone with a gauge. I have a voltmeter so I will also check my voltage.
 


dont think it would be that either as the car would just run of the map sensor then. unplug it anyways and try again just to be safe but i dont think so. if you dont have a fuel pressure tester then after the car stalls push the shrader valve on the fuel rail and see if you got pressure. this isnt the safest test or the most accurate but if you havde none at least you r heading in the right direction. if fuel jumps out then you r not dealing with a pump problem.
 


DOUGLASMELTER said:
dont think it would be that either as the car would just run of the map sensor then. unplug it anyways and try again just to be safe but i dont think so. if you dont have a fuel pressure tester then after the car stalls push the shrader valve on the fuel rail and see if you got pressure. this isnt the safest test or the most accurate but if you havde none at least you r heading in the right direction. if fuel jumps out then you r not dealing with a pump problem.
Click to expand...
Please note that if you are a smoker do not have any open flames or sparks present when performing this test.........
 
To diagnose this we need to determine if the issue is fuel or spark. The rest we should be able to accept as working properly.

Pull a wire off a coil pack and crank over. See sparks jumping around? If yes..spark tests concluded. We will assume the wires and plugs are new/good.

Next up.. Get a piece of vaccume hose about 8 or so inches and hook it to the LIM vacuum port under the snout of the SC. Using a can of highly flammable brake cleaner.. start the car and mist the cleaner into the vacuum line with the tube that comes with the can. If the car continues to run past the normal, then your issue is fuel.

Your symptoms sound like you have a security issue and need to security relearn the car.
 
As long as I bend the bottom left pin of the fuel pump speed control relay the car runs fine. I went for a ride with the car yesterday and the motor sounded and responded great. I just cant figure out why I have to bend that pin???? Besides that the only other problem I have is that my fuel gauge reads that its way past full, but I only have a quarter tank. I switched the fuel sending unit with the the one in the 97" GTP but that still didn"t fix the problem. At this point, I'm happy that the car runs as smoothly as it does.
 
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