Sarge

[SGTDRH]

I havea 1996 chevy silverado 350 ci. Starts easy when cold,after i let it run a little bit, it won't start unless i hold the accelorator down. It runs great after it is started. No miss or anything. I put a new tps, and a fuel pump relay it still does the same thing. Any ideas? Thanks sarge

[TURFKING]

diagnostic scanner!

[scotts62]

Scanner for sure but i would say the cool temp sender..

[TURFKING]

intake air sensor? map sensor? Scan that bad boy! I have been done down that road of replace it until it runs right. SCAN IT!

[ChevyTech]

Welcome to the board!

It could have a leaking fuel pressure regulator or a leaking poppets flooding the engine with extra fuel. You could test the fuel pressure to see if the regulator is leaking. A leaking pressure regulator will bleed off the pressure after the engine is shut off. The extra fuel makes it hard to restart when hot. Leaking poppets on the fuel spider are harder to diagnose.

Another possibility is the IAC may not be working.

The IAC (Idle Air Control) controls the air passing through a throttle pate bypass passage.

The IAC (and computer) control the idle speed.
The IAC (and computer) is what gives the engine a “fast idle” speed when started cold.
The IAC also supplies more air to compensate for the extra load when the A/C is on. If you have A/C and turn it on while listening carefully you should be able to here the IAC controlling the idle as the A/C clutch engages and disengages.

After the engine is shut off, and before it is started, the IAC should open somewhat. When the engine is cranked, and if the IAC does not open at all the engine will usually “load up” or “flood”.


AS Scotts62 mentioned, the coolant temp sensor is also a possibility.

Here are some links from the FAQ’s section. The location is different but the specs and testing procedure will work

Running Rich, or acts like no choke = Coolant sensor testing:
http://67-72chevytrucks.com/vboard/s...d.php?t=322811

http://67-72chevytrucks.com/vboard/s...d.php?t=379142

[SGTDRH]

Thanks for the tips. It was the coolant sensor. Replaced works fine. Back on the road again. Thanks to everyone have a good day sagre

[ChevyTech]

Thank you for letting us know what fixed it.

[SGTDRH]

Here i am again 1996 chevy silverado brakes cannot get a good pedal seems spongey put new calibers and wheel cylinders on plus new master cylinder. I was wondering if it could be the power booster?any ideas? Thanks sarge

[mountie]

Originally Posted by SGTDRH

Here i am again 1996 chevy silverado brakes cannot get a good pedal seems spongey put new calibers and wheel cylinders on plus new master cylinder. I was wondering if it could be the power booster?any ideas? Thanks sarge

You didn't mention a complete fluid flush...... (air/water in system?)

I woulda guessed the rear cylinders, but you changed them.