Please Help ! RMW....Cold start, EXCELLENT.... warm start, not so much

On my 1995 RMW, I recently replaced the water pump + thermostat, plugs & wires (THAT was fun), all new hoses, a couple of the requisite seals, and a new Optispark - and it wasn't the cheap-o Optispark, it was the $ 185 setup.... either way, the car hums like a kitten when it's running. However, I have recently been experiencing a unique phenomenon....

When my girl sits overnight, she starts immediately in the morning - and I mean INSTANTLY starts.

However, when she's warm, it takes a good number of turns to get it running - and even some gas pedal pumping.

What's going on ? Can anyone steer me in the right direction ?

Thank You in advance for your opinions !

Sincerely,

Andy

Your problem sounds like an injector "dripping" when you shut the car off,. the injector doesn't hold fuel pressure and leaks. When the engine is cold the extra fuel lets it start quickly. When the motor is hot, it,s too much fuel,. Try pressing the gas pedal right to the floor and holding it till it starts when you need to start it hot, that may help your symptoms but won't cure the problem.

Pumping the gas pedal will do nothing much on a MPFI engine,. give your foot a rest,. 

Nick

To help you.. here is the trouble shooting guide recommendations for engine hard to start when hot:

Dirty Air filter
Bad engine ground connection
Fuel not reaching the injectors(or injectors not working properly)
Defective ignition system component
Defective ECU component (temp sensor, throttle position sensor etc)
Intake manifold vacuum leak

That said, i would start where phantom suggests. At least on a TBI car you can take the air cleaner cover off and observe the injectors.. maybe something similar for LT1?

No can view the injectors on an LT1, they shoot right in, you can check your fuel pressure. Are you getting a CEL?

To add to what Phantom said, check the fuel pressure regulator for leakage. After it sits for bit remove the vacuum line from the regulator to check for fuel in the line. You could probably also do this when cold, there will be some residual fuel in the hose. As stated a cold engine doesn't mind a little extra gas, whereas a hot engine doesn't want it. If there is fuel in the hose, the diaphragm in the regulator is bad. Time for replacement.

I would hook up a fuel pressure gauge to see if the residual pressure holds or drops to zero. If it gradually drops to zero PSI suspect a leaking regulator or injector. If the pressure drops rapidly suspect a faulty check valve in the fuel pump, likely not the case here though. This would cause an extended crank whether hot or cold. Hope this helps you out in your diagnosis.