Is it possibe for a engine to misfire when giving it gas to start it (cold) ? The reason for the ? is that I have a random misfire only when the car is started cold.. Since my mods when the car is cold you have to give it gas to start it but when its hot it fires right up .. just a turn of the key.. I have been trying to figure this problem out with no luck so far. I'm thinking now that giving it gas causes it to be to rich which in turn causes the misfire..Comments , suggestions please...

 

Giving it full throttle to start puts the PCM in flood mode and causes the injectors to not fire so as to allow the flooded fuel to be burned. If this is the case, then when you try to start the engine without pressing the gas, you should have a longer cranking time before it fires up.

You could have 2 different problems but more likely one. First check the FPR vac line to see if it's wet. If so, your FPR is bad. More than likely, your fuel injector(s) are leaking fuel when the engine is off. You can check it 2 ways.

Put a fuel pressure gage on the fuel rail and see how fast the pressure bleeds off when you turn the engine off. If it drops quickly, you probably have a leaky injector. You should at this point, lift up the fuel rail with the injectors connected and suspend them over the intake. Have someone turn the key to on but not crank for 2 seconds at a time (you will have to cycle the power a few times) and check to see if any injectors are dripping. If any drip.

There's your sign.

 

Thanks, I'll check that also.. for the fuel press I can get one of those schrader hook ups at any auto store right ?

 

Not sure but the best one to get for the schrader valve is one with a hose so you can tape it to the windshield. This allows you to view it during several different events like driving down the road.

Their available at Sears and any tool truck.