89 vette starts hard when warm?

[goodi8650]

Hi everyone I recently purchased an 89 vette in very good condition, the only problem it has is once the engine has been run for the day when you go to restart it it cranks for awhile and smells rich out the exhaust. Stone cold you touch the key and it fires, I gave it a good tune up, cap, rotor, plugs, wires, andy ideas? coolant temp sesnor maybe? thanks guys

 

[Schrade]

Hi everyone I recently purchased an 89 vette in very good condition, the only problem it has is once the engine has been run for the day when you go to restart it it cranks for awhile and smells rich out the exhaust. Stone cold you touch the key and it fires, I gave it a good tune up, cap, rotor, plugs, wires, andy ideas? coolant temp sesnor maybe? thanks guys

CTS fault should give an check engine DTC.

Hard hot start, especially with gas smell, could be faulty fuel pressure regulator, or leaking injectors. Either one will show with a fuel pressure test.

Static test is without motor running. Connect the guage, turn on the key, let the pump prime the rails, and note how long before pressure goes to 0psi.

Dynamic pressure test you don't need to do right now.

After the static test, run the motor for a minute, kill it, then pull the vacuum line from the fuel pressure regulator. Get your nose right on it, and smell for STRONG gas smell. If so, the diaphragm is popped in it, and it's suckin' gas through that vacuum line into the intake. Cold is no problem. Hot will make hard start.

 

[vigman]

I feel your pain

My guess is the mystery 9th injector.....
Look in the book... there is an additional injector that " primes " the plenum..

the circut that controls it.. isn't very smart.. I unplugged my sender ( front of the block ) will look up wiring color codes later...

That cleared MOST of my warm rich start issues..


Vig~

 

[vetteoz]

My guess is the mystery 9th injector.....Vig~

Not on '89.
Injectors are probably leaking down when hot flooding intake; well documented problem.
http://forums.corvetteforum.com/c4-general-discussion/2356597-leaking-injectors.html

http://forums.corvetteforum.com/c4-tech-performance/2052169-hot-engine-no-start.html

http://forums.corvetteforum.com/c4-tech-performance/992599-leaking-fuel-injectors.html

http://forums.corvetteforum.com/c4-tech-performance/894119-how-do-i-test-for-leaking-injectors.html
Next hot start; crank with the throttle open and see if it starts faster.Having throttle open cuts out the injectors so it is firing on what fuel is in intake without extra added.

How to test
http://forums.corvetteforum.com/c4-...-ohm-check-injectors-instructional-video.html

http://forums.corvetteforum.com/c4-tech-performance/894119-how-do-i-test-for-leaking-injectors.html

 

[vigman]

OZ!

Did that stop in 89?? Mine had it in 88.....

Sorry If I gave bogus info out


Vig~

 

[Hib Halverson]

First thing to do is read the Factory Service Manual's instructions as to testing fuel pressure. Buy yourself a fuel pressure gauge then run those tests.

My guess is you have one or more leaking injectors.

 

[vetteoz]

Did that stop in 89??

Choosing a T.P.I Unit

Choosing a TPI Unit 2