When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hello,hope some one can help.
94 vette was getting a long start
replaced the fuel pump, i was getting no
pressure on the old one. new one in cranked
right up.Took it home sat for a few, went to
start same thing long start but it does start.I think i
replaced the fuel pump relay. At least it is where i
think it is located,under the dash on driver side.( it is
on a block of 4 other relays ?).
You should check the fuel pressure. Key on. Running. Key off.
Usually a long start is caused by the fuel pump relay not energizing. The oil pressure switch has to take over. It takes several seconds to build up enough oil pressure for it to turn on the fuel pump.
Hey everyone.
I checked fuel pump pressure key on 20, car running 29. This is a new fuel pump.Key
off it drops to 0, i do think this is low right?
Thanks for any help.
Check the fuel pressure regular (FPR). It and cause a long start if it is leaking fuel back into the manifold (from vacuum line) loading it up with fuel. It may also cause your loss in holding fuel pressure.
Pull off the vacuum line and see if it is wet. Turn key on and see if fuel comes out of FPR.
No fuel in vac.line changed FPR, also fuel pump relay is working as is fuel pump working, i hear it come on.still low pressure 29 psi when running,turn off engine it drops to 0 within
seconds...
No fuel in vac.line changed FPR, also fuel pump relay is working as is fuel pump working, i hear it come on.still low pressure 29 psi when running,turn off engine it drops to 0 within
seconds...
Usually a rapid drop off in pressure at key off means one or more injectors are leaking. Sometimes the relief valve in the fuel pump will cause this.
I believe your fuel pressure should be around 40 PSI. It sure sounds like there is something wrong with it, either mechanically or it's the wrong model for your application.
I think you need to pull the pump out and revisit your installation. There could be a broken hose or bad connection letting fuel out back into the tank. The pulse dampener might also be broken, cracked or blocked causing poor fuel flow. But if the pulser was only blocked, it probably would not cause fuel pressure to bleed off so fast. Sounds like you covered everything topside of the engine.