Gyvven Posted October 13, 2010 Report Share Posted October 13, 2010 I was driving around this past weekend when the did a small stutter and ran a little poorly. I got home and didn't think much of it until I tried starting it the next day and it would start for a second then die. I checked spark, that was fine. I checked everything I could think of and found the fuel pump wasn't coming on. So narrowing it down to that I started checking that, but not having my multimeter on hand I could only make some guesses. I checked all the fuses, they were good. I put in a tested good fuel pump and that wasn't it. I replaced the fusible link that's on the battery with a piece of wire, because it felt like it had a soft spot, and that wasn't it. I should have my multimeter back tonight and will be able to see if I'm getting juice to the pump connector. If I'm not getting signal to the plug what other things can I check? Link to comment Share on other sites More sharing options...
87Black_Stallion Posted October 13, 2010 Report Share Posted October 13, 2010 Is your fuel gauge working? Link to comment Share on other sites More sharing options...
87Black_Stallion Posted October 13, 2010 Report Share Posted October 13, 2010 Fuel pump is driven by a control relay that sits above the ecu. Did you run a power wire to the fuel pump test connector by the airbox while the fuel pump line wass off the throttle body? Link to comment Share on other sites More sharing options...
Gyvven Posted October 13, 2010 Author Report Share Posted October 13, 2010 I haven't yet. I do hear a relay over by the passenger kickplate clicking, so I was assuming the relay was good, but I'll try the test connector tonight. I'm guessing that if that doesn't work, then that relay is bad? Link to comment Share on other sites More sharing options...
Gyvven Posted October 13, 2010 Author Report Share Posted October 13, 2010 Oh, yeah. The fuel gauge is working. Link to comment Share on other sites More sharing options...
Indiana Posted October 13, 2010 Report Share Posted October 13, 2010 What year is your car? If its a pre88 your ignitor might have just died. No ignition pulse and the ECU will not fire your injectors and the fuel pump will only run with the ignition key in the cranking position. You can check wiring back to the pump and if the pump works by using the pump test port. Early model http://www.b2600turbo.com/images/Fuel%20P1.jpg Late model http://www.b2600turbo.com/images/pumptestport1.jpg Link to comment Share on other sites More sharing options...
Gyvven Posted October 13, 2010 Author Report Share Posted October 13, 2010 It's an 89. And if the test port works, then what? Link to comment Share on other sites More sharing options...
Gyvven Posted October 13, 2010 Author Report Share Posted October 13, 2010 I just ran out and tested the fuel pump check terminal and the pump comes on. Then I found my big green book, that says 1989 Chrysler Conquest on the front, and looked up the fuel pump circuit and it showing me a sub fusible link 2, which I don't have. When I was working on the fusible link for my headlight I mentioned that and was told that the later models didn't have a sub fuse 2, BUT IT'S IN MY BOOK! So now that I know the fuel pump is good, where can I start looking for this problem? Would it be the main eci relay? It makes clicking sounds like it should. Link to comment Share on other sites More sharing options...
Indiana Posted October 13, 2010 Report Share Posted October 13, 2010 The negative coil terminal has two wires on it, one is for the tach in the dash that's the metal thing with the two wires from it one is white and one is black and the other wire leads back to the ECU. The ECU doesn't get a tach signal from the "tach" in the instrument cluster it comes from the coil. That metal thing is a resistor for the instrument cluster tach. Link to comment Share on other sites More sharing options...
Gyvven Posted October 13, 2010 Author Report Share Posted October 13, 2010 So you're saying that because my ecu doesn't think the car is turning over it's not letting the fuel pump turn on? Would this also explain why my tach would occasionally stop working? I'll run out and check it now. Link to comment Share on other sites More sharing options...
Indiana Posted October 14, 2010 Report Share Posted October 14, 2010 The ECU doesn't turn the pump on but it does send a signal, voltage, to hold the relay closed so the pump stays on and if there is no tach signal the ECU cuts out that voltage to the relay and the pump shuts off. The cranking position of the ignition switch is an over-ride that gets the motor started then just the ECU holds that relay closed so the pump runs. If the coil is bad or the wires to it have bad connections that is a possible cause. http://www.b2600turbo.com/images/ignsequence.jpg Wires to the control relay, this relay rarely has any problems and I've never seen a bad one http://www.b2600turbo.com/images/IM000985.JPG http://www.b2600turbo.com/images/IM000989.JPG http://www.b2600turbo.com/images/IM000993.JPG. 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. Link to comment Share on other sites More sharing options...
Indiana Posted October 14, 2010 Report Share Posted October 14, 2010 There under the mounting bolts of the ignitor of that bracket that holds the small relays are two black wires with band markings to a singal ring terminal, that's the ground for the ignition components and that must be clean. Is that connection dirty or screwed down into paint or under a rusty screw? Link to comment Share on other sites More sharing options...
Gyvven Posted October 14, 2010 Author Report Share Posted October 14, 2010 Thanks for all of the input Indiana. Your suggestion about the resistor prompted the fix. I checked the resistor last night and found that it was 2.36k ohms. I figured that was probably ok since it read something other that infinity. I then decided to start checking the wires going back to the ecu, and guess what I found... The stupid ecu plug had fallen out, but not so far that you could tell by looking at it. That was it, car's fixed. I just wish I had come across that idea before I swapped in a fuel pump. On the plus side I got a new multimeter and timing light. Thanks for all the help. Link to comment Share on other sites More sharing options...
Technology Posted October 14, 2010 Report Share Posted October 14, 2010 I'm going to remember that you have a timing light now, haha. Link to comment Share on other sites More sharing options...
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