87 Stock FPR on Fuel Pump?

[MacTR]

Hey guys wondering about fuel management on these cars. I see on the stock fuel pump there is some sort of regulator between it and the fuel line. Question is, what does this do? A check valve of sorts? I don't have another to compare it to, but it looks like it might just be a big Banjo fitting.

 

I purchased this car and the pump is missing this part of the pump assy. I ran fuel line straight off the end of the pump. Runs really rich and get a nice black smoke screen when the secondary injector fires, I'm thinking too much fuel pressure (duh)lol.

 

Im asking because this is a fuel return system as opposed to a dead-head system, is it still possible the pressure is too much because of the missing parts on the fuel pump or should I be looking elsewhere?

 

Another issue is the fuel pump was dead in the key on position, but runs while cranking. Looking into the ignitor but never see a problem with the tach not working (I wired the pump from a switched source). I'm beginning to think this was a mistake as the ECU/Fuel control is probably not working at all.

 

Advice?

Edited October 25, 2010 by MacTR

[Indiana]

No the ECU can't turn the pump off if the engine dies in a crash. The ECI fuse link may be dirty but that missing part is a damper/check valve. The FPR is on the throttlebody. What year is the car? If 87+ then your black colored injector is primary and it will run with only it plugged in and that primary wire may be on the larger secondary or the CTS wire plugged incorrectly to the temp. sending unit. or an injector stuck or dirty

 

 

Sounds like you need to download a factory service manual but here's link for you how the ECI system works:

 

http://www.b2600turbo.com/ECI%20System.htm

 

 

http://www.b2600turbo.com/images/reg1b.jpg

 

http://www.b2600turbo.com/images/reg1a.jpg

 

 

http://www.b2600turbo.com/misc%20gallery/injmixer.jpg

 

 

[MacTR]

I will read-up on this more. I have tried a couple of different injectors with similar results.

 

Going back to the beginning, the pump would not run in key on position, but would the in start position. I wired the pump to a switched source in the fuse panel and the car runs. Question: if the igniter was bad, the car wouldn't run even if I had the pump rigged this way, correct? There must be an explanation as to why the fuel pump won't run, why I don't see power on the pump wire from the relay in "key on" position.

 

This thing is just dumping fuel, there must be a simple answer. I'll try some more ideas and post the results later.

Edited October 25, 2010 by MacTR

[Indiana]

Stuck injector, take the pipe off and look. There is a pump test port. The pump will not run with the key "on" its not powered from the ignition switch but it is in the cranking position. The control relay holds the pump relay closed from a signal from the ECU and the ECU needs an ignition tach signal to do that. No ignition signal, pump will not run. Dead ignitor, no pulse.

 

Injectors may appear to be the same but the nozzle openings are different and are identified by a stamped letter in the side of them.

 

Here's the injector id code and where the pump test port is. If the ECI fuse link is dirty the ECU isn't going to be able to leave the pump on even if there is an ignition signal and its common for that to be corroded.

 

http://www.b2600turbo.com/injection_mixer.htm

 

 

This is the control relay

 

http://www.b2600turbo.com/images/IM000993.JPG http://www.b2600turbo.com/images/IM000985.JPGGet about 10 inches of the wires after the plug so there will be plenty of length to splice and attach to the new connectors, fuse bank positions and other relays.

 

There are 8 wires all different colors.

 

From top to bottom their color and control relay position according to the C/S service manual and a short description.

 

BW-black/white stripe 01 / (+) output / turns on the Fuel Pump when starter is cranking or engine is running

 

WR-white/red stripe 02 / (-) input / signal from ECU to activate fuel pump relay after

 

ign. switch moves from "start" position and engine is running

 

BR-black/red stripe 03 / (+) output / when ignition "on", this sends power to the injectors

 

B -black 04 / (-) grounded to body

 

BY-black/yellow stripe 06 / (+) input / from ign. switch "start" position

 

this activates a relay that turns on the fuel pump

 

R -red 05 / (+) output / when ignition "on", this powers the ECU

 

L -blue 08 / (+) input / from ign. switch "on" position

 

this activates a relay that powers the ECU and the injectors

 

B -black 07 / (+) input / fuse link back to Battery positive terminal

 

Here's the pigtail from the control relay.

 

http://www.b2600turbo.com/images/IM000933.JPG

 

The "control relay" is actually two relays ( magnetic coils ) in one and how the control relay functions is that when the ign. switch is in the "on" position that energizes one of the two coils via position 8 (14ga) and that takes the current coming in from position 7 (16ga) and passes it through to positions 3 and 5. When the ign. switch is in the "start" position that energizes the other coil to pass more of the current from position 7 through to position 1.

 

 

[Caliber308]

Until you install a Fuel Pressure Gauge at the Throttle Body. You, I, nor anyone else can tell you what it is.Do a search in the Starquest FAQ Forum on how to do it. It's on Page four.

 

Bill

Edited October 26, 2010 by Caliber308

[MacTR]

Thanks Indiana, I had a dead power wire to the fuel pump, fixd correctly now.

 

And the primary injector was stuck, leaking gas constantly.

 

Thanks for the ideas