Fuel Fuel pressure issues(UPDATE)

JDFoxbody91

Member
Jul 30, 2020
8
1
13
40
South Carolina
I need some assistance guys. Just bought a one owner 91 LX that has been sitting in the garage for about 3 years. It would turn over but would not start. It was running when it was parked. The car was in good condition overall so I bought it anyway. I started working on it today and I cant get any fuel pressure. I dropped tank and cleaned it out. Installed new fuel pump, fuel filter and fuel pump relay. Checked the fuel switch in the trunk also but I still have no pressure at the fuel rail. I also checked voltage at the pump and its good. Any other ideas??

(Update) Problem solved. First, thanks for the suggestions guys. Second, it would help if I looked at the right print for my year model.:nonono: I started over and had 12 V on the pink wire but relay would never click on. Checked voltage at the PCM relay and had 12V on the yellow but the relay would never engage. The problem ended up tracing back to the ignition switch. Replaced ignition switch. I also decided after the fact to replace the PCM relay also. It worked but it looked rough so I replaced it while I was thinking about it. Even though it had been sitting a few years it fired right up. Now its time for a tune up(wires, plugs, etc). Thanks again for the suggestions .
 
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africansnowowl

Active Member
Apr 29, 2020
82
36
28
37
San Antonio
May sound stupid, but make sure it doesn’t have a kill switch you forgot about, or didn’t know about. I had this exact problem on mine. Replaced the pump, inertia switch, relay, an hour of tracing wires before i found out the previous owner neglected to mention the kill switch under the seat.
 

Blown88GT

Founding Member
Nov 13, 1999
2,144
505
164
Palm Beach Gardens, FL
"Voltage at the pump" indicates the pump is running.
At the pump & at the connector to the tank are not the same.
How much voltage? It's won't provide pressure at <10V.
If the pump is running & there is no fuel pressure, it can only be a few things.
1. Fuel pump is bad (OP installed new pump).
2. Fuel filter is clogged (OP installed new filter).
3. Fuel supply line is blocked.
4. Fuel pressure regulator is bad. If you have 0 psi & the pump is running, you are pumping raw fuel into the intake through the vacuum line on the FPR.