fuel pressure regulator trouble
#1
Member
Thread Starter
Join Date: Jul 1999
Location: United States of America
Posts: 130
Likes: 0
Received 1 Like
on
1 Post
Car: Firebird
Engine: LG4
Transmission: Auto
fuel pressure regulator trouble
I'm installing a SD TPI unit and installed a new bosch pump at the same time. When the fuel pump runs with key on, the pressure goes to 45 psi. Once the pump shuts off after 2 seconds, the pressure drops to 0 in 5 seconds. I pinched off the rubber return line, and when the pump runs, it goes to 70psi and holds once the pump shuts off. Lost maybe 3 psi over 15 minutes of off time. Seems to be the regulator. I replaced the diaphragm with a delco unit and have the same pressure loss problems. Could the problem be the seat in the regulator? It seems smooth but has a weird coloration in one spot.
#3
Junior Member
Join Date: Dec 2013
Location: Ontario
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1988 GTA Trans AM
Engine: 305
Transmission: 5 speed
Re: fuel pressure regulator trouble
hmmmm I did this same test last year, so i replaced FPR with a ac delco, same problem, so I then got a adjustable one, same problem, pressure drops to 0 after key off instantly
#5
Junior Member
Join Date: Dec 2013
Location: Ontario
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1988 GTA Trans AM
Engine: 305
Transmission: 5 speed
Re: fuel pressure regulator trouble
so leaky injector, that would be a lot of gas leaking out, im thinking more in the pump
can i install a inline check valve on the return line?
can i install a inline check valve on the return line?
#6
Member
Thread Starter
Join Date: Jul 1999
Location: United States of America
Posts: 130
Likes: 0
Received 1 Like
on
1 Post
Car: Firebird
Engine: LG4
Transmission: Auto
Re: fuel pressure regulator trouble
Follow up:
I replaced the whole regulator with another one I got off ebay. No more pressure loss. I even tried with my old diaphragm and it still holds pressure. Must have been that seat that was leaking.
I replaced the whole regulator with another one I got off ebay. No more pressure loss. I even tried with my old diaphragm and it still holds pressure. Must have been that seat that was leaking.
Thread
Thread Starter
Forum
Replies
Last Post
tompumped
Tech / General Engine
5
05-29-2018 05:18 PM
PatrickRSpl
Power Adders
3
02-27-2005 02:13 PM