lltrevino

greetings i have a t the moment a fairly stock 1986 corvette, i am experiencing a problem with. on cold start ups for the day, this car is a beast to start! i could crank steady, and the car wont even pop. i just crank for 1 second and stop, wait a couple of seconds and repeat. usually around the 8th time, it starts popping over, than a couple more times like this, and than it starts, and runs flawlessly rest of day. fuel pressure fine, complete tune-up, was no help. is this a suspect for leaking injectors? how do i test for this? it does seem, when car sits overnight, this problem occurs only. also seems that the warmer it gets outside, the tougher it is to start. please some input. i do have a fsm, among other testers. please help me start correcting. THanks for your time.

byebyeL98

What do you mean by "fuel pressure fine"? Did you put a pressure gauge on it? What did it read while the engine was running? What did it read when you shut the engine off? If it dropped down to 0 quickly, you might have leaky injectors. There is a test procedure in the FSM for that.

lltrevino

around 42 psi it registered. held fuel pressure for about a minute after shut down. how long do i keep pressure gauge connected to verify? how long would be recommended to test after shut down?

lltrevino

I still am looking for advice.

byebyeL98

A minute is relatively quick. Did it go down to 0? You'll get varying responses, but most would be in the 5 minute to 30 minute range of holding pressure. Keep the gauge on for at least 30 minutes or until pressure is 0.

AGENT 86

Try planting the gas pedal to the floor during cranking. This will put the ECM into "Flood Mode" and it will cut back the amount of fuel delivered. If it starts quicker, it may be a sign that you have leaking injector(s).
The FSM has some good info on tracking down fuel delivery problems.
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf

lltrevino

i did a thorough fuel pressure today on a cold start. i cycled key on, went to 35#. started car up, went to 39#. shut car off, went immediately to 15# after shutting car, and turning key off. after 1 minute, down to 10#. around 15 minutes, read 0 #. i dont think these numbers are oem, so are my injectors leaking down? is this why cold morning starts are tough?

AGENT 86

It may be your injectors or one of the other pressure loss areas. You need to diagnose by pinching fuel lines. Follow the link/info I left in my other post.

Da Mail Man

... "me" thinks so or may be one of the check valves...

bldavis11

You can crank for longer than one second. Three to four seconds it how long I hold vehicles too for starting. I then give it about a ten second rest and try again. One second might not be enough time with possible fuel delivery problems!

lltrevino

1 second cranks work the best. if i sit and crank steadily, the engine wont do a thing except spin. no popping or kicking. if i will crank for 1 second at a time, it will at least start kicking over around the 8th try.