fuel pressure problem
 

hello

when i start my car its cranking a long time before its starts.
I have just checked the fuel pressure and with engine running the pressure is about 40 psi and when i turn it off it drops to 0. if i just turn the key(engine off) some times i dont get any pressure.

anybody know if its the pump or the fuel pressure regulator ??

thanks claus

Re: fuel pressure problem
 

Sounds like the fuel pump relay is not working.
Will cause long crank time because the pump is being turned on by the oil pressure switch.
Would also get no fuel with key on, engine off.
Jp

Re: fuel pressure problem
 

Oki and how do i test the Fuel pump relay ?

Re: fuel pressure problem
 

check for power at the pump feed wire with a test light or multi meter
should power up for a few seconds when you turn the ignition on

if no power then check for power/earth from ecu at the relay

After I did my engine swap I had a hard start issue. It was due to the fuel pressure reg. If you can find the thread on here that I started, probably 2 or 3 pages back, a member was kind emough to provide a flow chart from a gm manual to diagnose this issue. Goodluck

Re: fuel pressure problem
 

Here's one. http://chevythunder.com/fuel_system_diagnosis.htm Here is the relay chart. http://chevythunder.com/fuel_pump_diagnosis_chart.htm

Re: fuel pressure problem
 

Thanks will try that.

When engine is running i have about 40-42 psi pressure and when i turn it off it holds the pressure. But if i then turn the key to ing on the pressure is at 0-5 psi.