North American Turbocoupe Organization



Fuel issues on my old '86
Blue86 Offline
Junior Member
#1
Hi all,
New member here. My old '86 turbocoupe is bone stock with 330,000 miles on her (original engine and turbo!). I know the original owner. I drove her every day up until a few years ago when it appeared the head gasket was leaking (losing coolant and running hot in summer). She still ran great though. I had just got my '83 Mustang running so I switched to it awhile. Anyhow from time to time I would fire up the bird and keep her going. It has been over a year since I last started and drove her.

So here's my problem: I can't get her to start. It seems like the fuel pump isn't putting out any pressure since the schraider valve under the hood has no pressure at all and no fuel. I checked out your excellent fuel pump troubleshooting guide and shorted the EEC plug lead and it sounded like the pump was running - but rather weakly. I could only hear it if I was under the car close to the fuel tank. I also have my inertia switch shorted for now to eliminate that possibility. I did get just a little burst of engine run so I am pretty sure the ignition system is OK. So I figured I would pull the fuel filter to see if it was clogged. It seems that it is not the problem since I can blow through it easy enough. I noticed that no fuel is draining from the tank with the fuel line disconnected from the fuel filter tank side line. Is this normal? I would expect it to drain easily even with the pump turned off. I just tried to see if I got any fuel flow with the key ON and no fuel filter expecting a flood of fuel under the car. Nothing... no sound and no fuel. Obviously the pump is not pumping. So do I drop the tank to check pump connections and/or replace the pump? Is there a way to run 12V from the battery to the pump relay connector bypassing a faulty relay instead of dropping the tank?

Thanks for any advice.
1986 stock turbocoupe with 330,000 miles on original engine and turbo.
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turbird77 Offline
Member
#2
Yes, pull the rear seat back off, behind it, hidden just behind the diagonally running metal support structure of the package tray (on the drivers side) there is a 2 wire connector, both of the wires will be pink. Look at the pink wire on the right side of the connector, the one closest to the connector clip. This is the power feed wire for the fuel pump. Apply 12V to this wire. If the fuel pump runs normally then, that means that the FP relay in the IRCM has died. Otherwise most likely the pump itself has finally bit the big one.
88 TC - Work in Progress.
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Blue86 Offline
Junior Member
#3
Thanks!

I'll give that a try and see what happens.
1986 stock turbocoupe with 330,000 miles on original engine and turbo.
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RDOG Offline
Posting Freak
#4
The 86 does not have a black box(IRCM)


I recently changed out my fpr(smelled fuel in the vaccum hose), fuel pump (could lightly hear it)and fuel filter( car sat like yours) and car still wouldnt start. I then read that it was possible that the pip sensor in the distributor could cause this problem.

I had fuel pressure (depressed the shrader valve and fuel shot out)
I had spark
I could hear the pump
New TFI
Car would not start.


Change my dizzy to a known good one, and she fired right up.
1986 Turbo Coupe. Boport StageIII head, Boport 2.1, Performance Techniques 50 trim hybird, StageII.63, stinger 3" exhaust, Phenolic spacer, Boglog header,NPR FMIC intercooler setup, kirban fpr, bigrmotorsports fuel rail, diablo water meth kit, CAI, remote mount TFI, CHE rear adj control arms, MAC girdle, 8.8 rear disc, aluminum drive shaft, H&R lowerings springs Tbird Turbo Specific, y MAS!!
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Blue86 Offline
Junior Member
#5
I didn't have time to do anything else this evening but I don't have any fuel pressure and it did try to run for a few seconds so I suspect the fuel pump/wiring etc. I hope it is not a fuel pump but I'll have to work through it to find the cause.

Thanks for your help!
1986 stock turbocoupe with 330,000 miles on original engine and turbo.
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Blue86 Offline
Junior Member
#6
Well I determined I have 12V at the pink wire leading from the pump relay to the fuel pump with the key ON and the EEC test connector pin shorted (to make the fuel pump run constantly according to the troubleshooting guide). No fuel is flowing and I do not hear the pump running at all. I also do not have any fuel level indication (empty tank) even through I poured 5 gallons of fresh gas in it and I am sure it had some old gas in there too.

So now I guess it is time to drop the fuel tank and see if mice ate the wires or if the pump has gone bad.

Any other suggestions?

Thanks
1986 stock turbocoupe with 330,000 miles on original engine and turbo.
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Jeff K Offline
Administrator
#7
How did you check for 12V at the pump? DMM or test light? Always use a test light for power circuits, as a DMM can give false positive readings..... Even with high resistance in the circuit, a DMM will read system voltage due to its high input impedance.
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.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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RDOG Offline
Posting Freak
#8
Dropping the tank isnt all that hard. After you do it the first time, its cake after that.

You only need two jacks, 4x4 5' peice of wood, 13mm socket for tank straps, 8mm socket filer tube support, brass pipe or punch to tap off the fuel pump assembly ring, hammer, and thats it.

Its a two hour job the first time and even less after that. Helps when you have a buddy help you, especially when you now have a tank with 6 gallons of gas in it.

1986 Turbo Coupe. Boport StageIII head, Boport 2.1, Performance Techniques 50 trim hybird, StageII.63, stinger 3" exhaust, Phenolic spacer, Boglog header,NPR FMIC intercooler setup, kirban fpr, bigrmotorsports fuel rail, diablo water meth kit, CAI, remote mount TFI, CHE rear adj control arms, MAC girdle, 8.8 rear disc, aluminum drive shaft, H&R lowerings springs Tbird Turbo Specific, y MAS!!
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Blue86 Offline
Junior Member
#9
I used a DMM Jeff. I did read your guide but apparently forgot about needing to use a test light. Thanks for pointing this out as it may not be the pump if I am not getting enough current to the pump motor. I'll try a test light or direct wire from the battery + lead to the fuel pump.
1986 stock turbocoupe with 330,000 miles on original engine and turbo.
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Blue86 Offline
Junior Member
#10
Thanks RDOG. I have some of the work done on dropping the tank. Rain is delaying much progress right now.
1986 stock turbocoupe with 330,000 miles on original engine and turbo.
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