L98 will not hold fuel presure
#1
Le Mans Master
Thread Starter
L98 will not hold fuel presure
My 1990, L98 when turning the key on won't show pressure but with several tries to start it will and the pressure goes up to 40 lbs and runs ok. then when I turn the motor off the fuel pressure drops right away to 0. Then it takes several tries to restart?
Last week I changed the in tank pump and inline fuel filter due to low running fuel pressure. That helped it run ok. now this new problem?
Last week I changed the in tank pump and inline fuel filter due to low running fuel pressure. That helped it run ok. now this new problem?
#2
Advanced
Please check for a leaking fuel pressure regulator. Pull vacuum hose, that runs from the fpr to the manifold and check for fuel dripping or a strong fuel smell at the hose end.
Otherwise it could be a leaking injector. I believe your 1990 has no cold start injector. That was the leaking one at my 1985.
Otherwise it could be a leaking injector. I believe your 1990 has no cold start injector. That was the leaking one at my 1985.
The following users liked this post:
Bangkok Dean (09-04-2017)
#3
Team Owner
Crimp off the return line and turn the key so it pressurizes. See if it holds pressure then.
#4
I would also check for a ruptured pulsation dampener in the tank. Remove and replace with a short piece of fuel line. That was one of the causes of my pressure loss on my 85.
The following users liked this post:
Bangkok Dean (09-04-2017)
#5
Team Owner
It will need to be a hose rated for submersion. I really recommend that you get the install kit from. Racetronix
#6
Burning Brakes
#7
Team Owner
The following 2 users liked this post by aklim:
95BLKVette (09-17-2018),
Bangkok Dean (09-04-2017)
#8
Le Mans Master
Thread Starter
Finally fixed the problem. The in tank fuel pump had a leak in the fuel line in the tank itself. Now it holds 45 lbs pressure and actually starts right away and runs better than it had in the past.