North American Turbocoupe Organization



fuel injection issue..need assistance!
firedoctor Offline
Junior Member
#1
heres the deal, weve got an 86 turbo bird. it will not start or run on anything but starter fluid. there is spark, and we have fuel to the rail and back to the return line in the tank. the fuel pressure is adequate for the car to run. when a test light is put from ground to the injector plug, i get positive flow on both connectors(both tabs have current). this is consistent with an 87 turbo bird that runs well.i need to know how the injector is supposed to work, and where the control for it is located. we believe that the computer controls the injection system, but we dont know which one, or where it is on the car. we are also sure that the injectors are good, and that the rail is not plugged or clogged. please help us to solve this issue, any input is helpful. if you are unsure of what we have and haven't checked, please respond with questions. thanks for all your help.

JOHN, and
Moller
My children are bleeding away my family fortune!
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Pete D Offline
Administrator
#2
The injectors are batch fired when the EEC grounds the circuit. The EEC (computer) is located behind the passenger side kick panel

The injectors are grouped into 2 sets of 2. They fire once each crankshaft revolution. The computer pin #s are 58 and 59
http://natomessageboard.com/cgi-bin/ulti...713#000001


It takes 20 or more psi FP just to get the engine to run. Just because yopu can get fuel to burp from the schrader valve does not mean fuel pressure is sufficient. If in doubt, run the fuel system diagnostics using a gauge.
http://www.turbotbird.com/techinfo/Fuel_...ostics.htm

Have you pulled the codes?
Pete Dunham


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firedoctor Offline
Junior Member
#3
fuel does not spurt from the lines, it shoots fifteen feet out of the lines from the tank...i am 110% sure that the pressure is good, as for the computer.....?????who knows?

now, when the motor turns over, niether one of the leads ground out (via testlight), so we are thinking wiring messup(lots of splices throughout car) or computer issue. when the car turns over, should one of the leads to the injectors ground out at all? when turning over, both leads remain 12v(+)is this correct?

question #2- what tells the computer when to open and close injectors, what feeds the computer information on when to fire injectors? how does all of this work, we are new to the fuel system electronics.
as for pulling codes, we have no way to do this for we have no code reader, will have one later though.
thanks for all your help.JOHN and MOLLER
My children are bleeding away my family fortune!
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Chuck W Offline
Posting Freak
#4
Has the car been sitting for a while? How do you know the injectors are "good"?

------------------
Any connection between your reality and mine is purely coincidental..
83 TC Clone, 87 Ranger (soon to be 2.3T), 84 XR7, 80 XR7, 86 XR4
NATO Member
83 TC Clone, 80 Cougar XR-7, 85 Volvo 244 Turbo, AND 88 Scorpio
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firedoctor Offline
Junior Member
#5
no, the car hasn't been sitting for that long. the injectors tested out fine on another running 87 turbo bird. everything we've posted is right, we have done everything very very thoroughly. we know the mechanics of the fuel system work, but its the electronics that are causing the problem.

we still need to know what tells the computer when to fire injectors.
My children are bleeding away my family fortune!
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Chuck W Offline
Posting Freak
#6
I was just asking if the car has sat for a while because I have known them to "stick" if they sit for a while(old gas = varnish). I've freed them up with a tap, tap, tap. Since you've said you've tested them and they work fine, then that's not an issue.

The only way the ECU would know to fire the injectors is from the ignition module, but you say you have spark. The PIP signal from the TFI module is what goes to the ECU and conveys the spark information. Check the distributor, the TFI plug/connection and the wire back to the ECU itself to make sure it's getting it's signal.

I'd check for continuity between the TFI connector and the ECU plug along that wire and check to make the all the connectors in the TFI plug themselves are engaged properly.
83 TC Clone, 80 Cougar XR-7, 85 Volvo 244 Turbo, AND 88 Scorpio
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TurboE Offline
Posting Freak
#7
I had a similar problem in my 88 and it turned out to be the Throttle Position Sensor (TP Sensor). I am not an expert on the electronics on this car yet, however have learned from every problem i've had. Unplug it and see if your car will start, it might not run great but if the car starts, then buy a new one. Learned this from a ford mechanic after replacing the fuel pump (last time i just replaced a part before fully diagnosing it). You might need to prime the fuel system, turning the key on to build up fuel pressure, if you've been bleeding the schrader valve.
-88 TC Black
5spd, Precision SC50 T3/T4, QH/SD Tune, Gillis, AFPR, 255FP, WB O2, K&N, Ported E6, 3" DP, ATR 2.5" Duals, 3:73 Rear, Konis, Eibachs, 18" Voxx Wheels, X Drilled Rotors.
-06 G35 Coupe Diamond Graphite
-97 Pathfinder
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rarebird83 Offline
Junior Member
#8
this problem might be impossible to diagnose if we do not know how it stopped running, did it just quit one day, or has it been parked for a week, or did someone bring it to you not running??? what is the cause of the no-start condition????? without knowing, we probably will not be able to give you a solid opinion
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firedoctor Offline
Junior Member
#9
Just for the record, this is an '86 automatic turbo bird. It was sitting in a junkyard for 4 or 5 months. It was a repo job. We brought it home to play with. It has a great artwork on the hood. Kinda like the ones the kids are putting in their back window nowadays but this was painted on the hood. It is kinda like a screaming eagle. Quite a bit faded now but must have really great in its day. We were able to get to run by spraying starter fluid in the throught the intake. So, that would tell me that everything works in the system EXCEPT the fuel actually going thru the injector. There is great fuel pressure & flow coming out of the rail. IT JUST WON"T RUN ON ITS OWN ACCORD. Also, there has been a lot of creative wiring. The wires to the injectors have been spliced as well. It appears to have been running for some time as the splices are older looking. The REPO man did say it was the guys daily driver & just "stopped" running one day. He really didn't know much more than that on the history of the beast.
My children are bleeding away my family fortune!
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Chuck W Offline
Posting Freak
#10
It alsmost sounds like it might be better to grab another harness and make sure it's in good shape and then pull out the questionable one and see what you get.....

------------------
Any connection between your reality and mine is purely coincidental..
83 TC Clone, 87 Ranger (soon to be 2.3T), 84 XR7, 80 XR7, 86 XR4
NATO Member
83 TC Clone, 80 Cougar XR-7, 85 Volvo 244 Turbo, AND 88 Scorpio
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