1996 Start issue

[WestTexasVette]

Just bought a 1996 LT1 with 37,500 miles. I am experiencing trouble starting the engine after car sits for a while (overnight, all day at work) It usually takes me 2 or 3 cranks to get started. Once, running the engine operates just fine…smooth idle, no missing. The engine will start just fine while coolant temp is hot. When engine sits for a while…starting troubles reappear. I am in the process of troubleshooting with local mechanic. Notice that fuel pressure gradually drops well below 40 psi when engine is turned off. I’m thinking fuel pump. What psi should the fuel system maintain while car rests? Any advice would be great. I’m a new user….site is very informative. Thanks a lot!!!

 

[vigman]

Welcome to the CAC!

And now the bad news


2 words

Leaking Injectors.

It could be the regulator.. but there is a good test in the shop manual.

Static fuel pressure around 20 ish PSI


Vig~

 

[WestTexasVette]

Wouldn’t leaking injectors flood the engine? Do you think the fuel pump could be allowing pressure loss? After an unsuccessful crank, I hear a short whining sound from the back. Thanks for the input...I really hope it's not the injectors!!

 

[UB2 SLOW]

What would be the long term outcome if you did not fix your injectors right away?

 

[sumoboy]

Try this...

... Here are the sure fail tests for the fuel system to save you time and money.. Take a fuel pressure gauge attach it to the schraeder valve.. turn the key on and off a few time to build up the pressure in the system... If you are having starting trouble the pressure will probably drop as soon as it hits 38 or 40 and the pump turns off it will probably leak back to zero within a few minutes. Ok now right after you prime the system pinch off the return line near the tank if the pressure drop stops it is a bad fuel pressure regulator.... Next pinch off the feed line if the pressure holds then the leak is before the point where you pinched the line IE fuel pump check valve..hole in the metal line on the sending unit caused by it rubbing on the inside of the tank you should visibly be able to see this if you pull the pump and the sending unit...(this was my problem) or the pulse dampener which is the piece between the pump and metal line on the sending unit.. the diphragm tears.. and last if you pinch both the feed and return line near the tank and the leak down of the pressure continues then a fuel injector is your problem.. This is the GM test.. saves time and money..