Hard starting problem?
 

My car is hard to start when warm and has sat for awhile. When it won't start I can hold it to the floor and it will start immediately but blows smoke. What gives? I have new plugs, checked wires, new opti., etc. Can this be the dreaded ICM or an injector? Car runs great once started. Thanks for any help fellas.

Jon

You probably have a sticky injector. By flooring it you already know it goes into flooded mode and then when it starts, if it is black smoke, that indacates you are burning off the puddle of fuel that formed. Put a gage on the fuel system and see if pressure stays up or slowly goes down once the engine is turned off. If it goes down, you need to be sure its the injectors. You should also have the injectors professionally cleaned on or off the car. Obviously one is much easier and less work.

While your looking things over, if you have a vacuum pump like the one used for one man brake bleeding, apply a small amount of vacuum to the fuel pressure regulator air line while its connected to the FPR. It should hold vacuum. If not it has a hole in the diaphragm and that could also give you your problem. However, if it were the problem you should have noticed bad fuel economy.

If you don't have a vacuum pump you could suck on it (yech) but use a long clear line so as to not suck up gas. :yuck:

Thanks for the info. The fuel pressure drops immediately when I shut the car off. It goes to zero within about 30 seconds.

Jon

Sounds like a leaky injector, the system should stay presurized when the car is off shouldn't it?

Cycle the ignition then pull the vacume line on the FPR and see if you have fuel in it....if you do it is toast. If its not the FPR its more tyhan likely a leaky injector.

Yes, I have noticed that there seems to be gas coming out of the top of the FPR when I pull the vacuum line. It is an Aeromotive and was put on when the LT4 conversion was done. Could this mean my AFPR is bad and should be replaced? Could this cause my hard starting?

Jon:confused:

As we had said before, if you have fuel coming out of the vacuum fitting of the FPR, then the diaphragm has a hole in it. It could very well be your problem. One thing is for sure, before you do anything else, change it.