91 lesabre starting probs

my 91 lesabre seems to not want to start after it sits in the hot sun for a couple of hours. it starts early in the morning when its cool out but when i get out of work after it sit in the parking lot all day it doesn't want to start. some people tell me it's vapor lock but i don't know. can anyone give me any suggestions on what the problem may be?:confused:

The best thing to do is check the fuel pressure after it has been sitting in the hot sun for a few hours. Do you smell fuel vapors inside the car, or does the engine run rich when it starts? “Vapor lock” should not be an issue with a fuel injected car!

they tell me that the fuel pump,filter and pressure are fine.no i do not smell any fumes in the car. i know that the pump is working because i can hear it when i turn the key on.:banghead:

Did you ever checke the codes?? some time check engine light will not come on.

no codes. thats because they say its an intermitent problem. they as in the mechanincs that i had look at it.:screwy:

Evidently, your mechanics do not understand that fuel pressure, or anything related to fuel flow, will not set a DTC (code)!

they did say the fuel pressure was fine it was 45. i think it is supposed to be between 40 and 47. i don't know i never had this many problems with a car before. this buick seems to have a mind of its own.:biggrin:

The proper fuel pressure for this is 37-41 PSI...

The pressure should not leak down... If it does you either have a bad Check Ball/Valve in the pump... A Bad fuel pressure regulator or possibly a bad fuel injector...

When you turn the ignition on is there fuel pressure? Say the 37-41 PSI I stated?

If you have the fuel pressure with the key on and it holds... Than you may need to look elsewhere..

And as stated by another poster, Fuel pressure issues will not set a DTC