North American Turbocoupe Organization



Ignition/drivability issues
BradM Offline
Member
#11
(01-28-2024, 07:15 PM)94VERTiGO Wrote: I thought that there must have been a problem with the gauge or the way I was using it. So this morning, I went out to confirm the 0 psi on the pressure gauge.  First I turned the key to the on position, pushed the schrader valve and fuel came out with very little pressure behind it.  I started the car and repeated pushing on the Schrader valve.  Again fuel came out, but very little pressure behind it. It sprayed maybe 3 or 4 inches up the screwdriver. 
I put the adapter for the pressure gauge on the valve, turned key "on" and pushed the adapter's valve to ensure fuel would come out.  Fuel came out but just a little like before. I then put the gauge on the adapter, turned key "on" and 0 psi.  Started the engine with fuel gauge attached and still 0 psi. 
Went to my '89 Jeep Cherokee, put the gauge on the fuel rail, turned key on, and gauge moved to about 2 psi.  Started Jeep and fuel pressure went to ~32psi.  Depressed gas pedal and psi jumped to about 40.  
So, the gauge works on the jeep. 
Went back to the Turbocoupe repeated test and still got 0 psi. Went to the trunk, could hear fuel pump running, knocked on the fuel pump shut off switch, fuel pump died and car stalled a few seconds later. 
Reset the shut off switch, started back up, and still 0 psi. \
The fuel gauge has a pressure relief button on a vent line that you depress after the test to relieve pressure and it sprays fuel out of the line on the test gauge.  While I was testing the Turbocoupe, I depressed that button and there was no fuel in the line although I could see gas vapor (like heat waves) coming out of the vent line.  
I will triple check with the fuel gauge this afternoon, but in the meantime.  ]
If I have to get a new fuel pump should I shop the 235LPH walpro or should I just get OEM spec.  I don't anticipate doing any mods for HP, but would the 235 LPH cause any issues or is as good or better than OEM?
Thanks

That's good testing. You confirmed it's near-zero psi and the fuel pump is running. I would check flow at the fuel filter (in front of the right rear tire). Disconnect the input and turn the key on to see a solid and strong stream of fuel. Then do the same for the output. It could be clogged. If this looks good, the only thing left in the system is the fuel pressure regulator. But I keep returning to your description of when the problem occurred (after you removed the intake and fuel rail) so a bad regulator seems unlikely (but possible). One other thought, I don't think this is possible but make sure your fuel line and return line are not switched.
1965 Mercury Comet Caliente; 1968 Mercury Monterey; 1969 F100 Ranger; 1982 Mustang; 1987 Thunderbird Turbo Coupe; 2017 Police Interceptor
Reply

94VERTiGO Offline
Junior Member
#12
Thanks for the reply.  I am now going down the fuel filter/pump, and or regulator rabbit hole.  
How would you test for regulator?
I did not remove the fuel lines so they should still be plumbed correctly. 
Unfortunately, it only seems that I can work on it is on the weekends, so it may be a few days before I can relay any more info.
Reply

BradM Offline
Member
#13
You can read through the steps in the link below. But check the vacuum line going to the regulator first. Then, if it were me, I would put the gauge on it and start the car. Then tap on the regulator to see if it might be stuck. Then pull a vacuum on it with a MightyMax pump (this should increase fuel pressure).

https://axleaddict.com/auto-repair/How-t...-Regulator
1965 Mercury Comet Caliente; 1968 Mercury Monterey; 1969 F100 Ranger; 1982 Mustang; 1987 Thunderbird Turbo Coupe; 2017 Police Interceptor
Reply

Jeff K Offline
Administrator
#14
20 or so years ago I had the short molded hose from the fuel pump outlet to the pump mounting flange develop a split. Only had a few psi fuel pressure on my in car fuel pressure gauge. After exhausting every troubleshooting avenue I could think of I dropped the gas tank to have a look. Found a inch or so long split in the pump to mounting flange hose within a a minute or so.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
11 Crown Vic Interceptor
14 Toyota Camry (wifes car)
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
Reply





Users browsing this thread:
1 Guest(s)



Theme © iAndrew 2018 - Software MyBB