conquesterd Posted April 27, 2010 Report Share Posted April 27, 2010 (edited) I have an '86 Conquest and in my quest to locate all related fuel pump relays and fuse links, I'm familiar with the one above the ECU which is actually two relays and is related to power to the pump. I hear conversations about another and haven't heard or scene a specific location explained. My problem is lack of fuel or pressure when system is opened, (fuel line disconnect) with ignition on, and while driving after sitting awhile runs fine for a short period and then when you give it gas it cuts out completely until you let off and then hardly will stay running. I've dropped the tank and drained and put remote power directly to the pump and it works. I've read others with similar problems and the process of elimination hasn't seemed to solve this. I don't want to put it back together, (tank-etc.). with out at least checking with all , (maybe replace) relays related to the fuel pump. I have an '88 for some parts, (eng/tranny and ECU are missing- future v8 build vehicle). So, if anyone has specifics it would be appreciated. Thanks, Conquesterd! Edited April 27, 2010 by conquesterd Link to comment Share on other sites More sharing options...
Indiana Posted April 27, 2010 Report Share Posted April 27, 2010 My problem is lack of fuel or pressure when system is opened, (fuel line disconnect) with ignition on , and while driving after sitting awhile runs fine for a short period and then when you give it gas it cuts out completely until you let off and then hardly will stay running.These are two different problems, well one is actually normal and the other is likely not the problem. Your fuel pump is not going to run with the ignition key "on" unless the ECU gets a tach signal and holds the control relay on, this is so the fuel pump isn't running with the motor not running. If the ECI fuse link (red one in the holder behind the battery) is dirty it still won't run the fuel pump while cranking with a tach signal. Fuse links being dirty are common as they are behind the battery and acid/fumes cause problems. If the ignitor is going out it does strange things to the ignition system. The ignitor is the plastic thing behind the ignition coil, it says "knock" on it. To test the fuel pump, run a jumper wire from the positive battery post to the check terminal. The check terminal is in the harness on the passenger fender apron in front of the cruise actuator, its a single unused terminal next to an unused round terminal. You have dirty injector clips and or dirty injectors. You have two rather large dispensing injectors, about 75-85lbhr that spray back and forth all the time, if one is dirty and sticky, reacting slowly and flooding out at lower rpms which makes it leaner at higher rpms, isn't seating, stuck open your car won't idle or run right no matter what else you do. They need cleaned and the crusty clips need replaced. The wire in your harness is crusty green keep going back in the insulation and get rid of all that ruined wire and its usually about 2-6" you have to cut away. If the clips have already been replace, inspect if they attached the new pigtail to this crusty wire in the harness or nice clean copper strands. There are more than one brand aftermarket clips but you can also re-use the stock plastic end if you just want to use only the wire and terminal end. http://www.b2600turbo.com/images/IM001016.JPG http://www.b2600turbo.com/images/IM001015.JPG You can see this terminal is corroded and shouldn't be used or washed, it is trash so is that green corroded wire attached to it. http://www.b2600turbo.com/images/IM001013.JPG http://www.b2600turbo.com/images/IM001019.JPG http://www.b2600turbo.com/images/IM001017.JPG Link to comment Share on other sites More sharing options...
Indiana Posted April 27, 2010 Report Share Posted April 27, 2010 Replace or clean fouled spark plugs when you are finished. Link to comment Share on other sites More sharing options...
conquesterd Posted April 27, 2010 Author Report Share Posted April 27, 2010 (edited) Replace or clean fouled spark plugs when you are finished. Thanks for your response: I had already checked the pump test lead and got nothing but when direct power to the pump it worked. I'll recheck that and follow up on other connections you pointed out. Just to follow up on my question if there other relays than the one above the ECU? Edited April 27, 2010 by conquesterd Link to comment Share on other sites More sharing options...
Indiana Posted April 27, 2010 Report Share Posted April 27, 2010 Something is wrong with the wiring or someone bypassed it and rewired it all years have that pump test port and it hasn't anything to do with the relay. There is only the one relay. Here's how it works... 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. If your ignitor is dying there is no tach signal and no fuel pump after it starts but it may start then die, this is VERY common for these to die and when dying do strange things. Your car might start but run like crap, it might not start one day but it will the next, it may start then die. If you can put the jumper wire from the test port to the positive battery post and the car run that is a sign your ECI fuse link is bad/dirty and it plugs in from the top but harness wires plug in from the bottom that black box is just a holder for some double ended terminals. You put power to the pump and it runs so did someone replace the pump? OEM pumps look like this http://www.b2600turbo.com/images/IM001596.JPG http://www.b2600turbo.com/images/IM001597.JPG Link to comment Share on other sites More sharing options...
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