1985 fuel pressure
Safety Car
Joined: Mar 2017
Posts: 4,174
Likes: 1,300
From: LeClaire Iowa
I just put new plugs in a month ago didnt smell anything also it runs great. I changed the fuel filter and noticed it only had one o-ring on it? Could the pressure have been escaping from the side that didnt have one?It never leaked gas though.I'll check the pressure tomorrow.
Team Owner
Joined: Jul 2004
Posts: 28,353
Likes: 3,253
From: Hartford WI
If it is an external leak, you should have puddles of gas. If you crimp off the return line and then turn the key on to "run", it pressurizes up and when you crimp off the feed hose, it sounds like a leaky regulator and/or fuel injectors. If you take it to FIC for a rebuild, assuming they are not Multecs, it should be good. When it comes back, change the regulator and rerun test.
Drifting
Joined: Dec 2000
Posts: 1,785
Likes: 91
From: Leander TX
I'm betting you have a leak on the sending unit where the pump connects to the fuel line at the pulsator. I'm having the 100% exact same problem as you. I tested all my injectors and zero leak, new FPR, new filter and I put a complete brand new fuel sending unit in (as my float sensor was bad too). In the process I put one of these damn things in between the pump and the hard fuel line (https://www.rockauto.com/en/moreinfo...6240&jsn=10918) and now lose fuel pressure almost instantly after the car is turned off. I'm 90% it's this thing as it's just sealed with a couple of o-rings and the fit didn't feel all that tight when I put it on the car. I'm going to rip the sending unit out again and replace the pulsator with just a rubber fuel hose to see if that fixes my problem. Those pulsators are stock and are supposed to help absorb some of the pressure spikes with the fuel system but I know most remove them at some point. If your car still has one, remove it and see what happens.
Thread Starter
Instructor
Joined: Apr 2013
Posts: 229
Likes: 2
I'm betting you have a leak on the sending unit where the pump connects to the fuel line at the pulsator. I'm having the 100% exact same problem as you. I tested all my injectors and zero leak, new FPR, new filter and I put a complete brand new fuel sending unit in (as my float sensor was bad too). In the process I put one of these damn things in between the pump and the hard fuel line (https://www.rockauto.com/en/moreinfo...6240&jsn=10918) and now lose fuel pressure almost instantly after the car is turned off. I'm 90% it's this thing as it's just sealed with a couple of o-rings and the fit didn't feel all that tight when I put it on the car. I'm going to rip the sending unit out again and replace the pulsator with just a rubber fuel hose to see if that fixes my problem. Those pulsators are stock and are supposed to help absorb some of the pressure spikes with the fuel system but I know most remove them at some point. If your car still has one, remove it and see what happens.
Team Owner
Joined: Jul 2004
Posts: 28,353
Likes: 3,253
From: Hartford WI
