xavier_87conquest Posted February 23, 2008 Report Share Posted February 23, 2008 i have a 87 conquest last week i change my bad wiring harness, i use a 88 harness. the problem is the engine dont last more than 5 seconds running. i check with a multimeter and all the sensor dont have any signal. i check everything is conected except the plug in the computer area. the plug should be in that area where the evaporator use to be but i can find it. this plug is for the gauges? or i have a bad ecu or something else disconected. Link to comment Share on other sites More sharing options...
Shelby Posted February 23, 2008 Report Share Posted February 23, 2008 please tell us what sensor or sensors do not have any signal , don't lump them all togather B38 or the body connector on the 87's is right near the ecu,, with in a foot or so,, on the 89's it's to the left behind the left edge of the glove box do a voltage test on the fuel pump test lead while you trying to run the engine Link to comment Share on other sites More sharing options...
xavier_87conquest Posted February 23, 2008 Author Report Share Posted February 23, 2008 ok i check again i have two problems one the fuel pump dont turn on i believe i left something desconected and two i check the tps, mas air flow, and the dont give me any signal. that plug what controls? Link to comment Share on other sites More sharing options...
mikec Posted February 23, 2008 Report Share Posted February 23, 2008 What you're describing is a non-working ECI control relay or dead ECI fusible link circuit. Basically: battery --> ECI fusbile link --> ECI relay --> Fuel pump, injectors, etc. The ECI relay (located above the ECU, behind the glove box, tucked into the "A" pillar bodywork) is held ON by the ECU when the ECU "sees" ignition pulses from the ignition coil "-" post - the same wire that drives your tachometer. As long as the ECU sees ignition pulses, it holds the relay ON. The ignition key START position is supposed to TURN the ECI relay on; that's what gives the pump and injectors power while starting the car... then once there is ignition the ECU takes over, keeping the relay on. Your symptoms sound like a problem in the ECI fusible link wiring OR the wire from the ignition switch START terminal to the ECI relay is not working. Go to www.starquestgarage.com and you'll find PDF files of an 88 factory service manual set; download the electrical chapter and the fuel system chapter. The diagrams are easy to read and quite complete; they also include the physical location of all connectors shown on the diagrams so you can use a voltmeter (not a test light!) to trace the +12volt signals I've described. Note that, unlike many fuel injected cars, StarQuests DO NOT run the fuel pump for 2 seconds or whatever when you first turn the key to ON. Instead, the key must be in START to trigger the relay & pump; then the ECU holds them ON. For troubleshooting, try this trick: on the starter motor (actually on the solenoid portion of it) there is a smaller wire... unplug that one wire connector. Now when you put the key in START the engine won't be turning - you won't be killing your battery needlessly. Have a helper hold the key in START while you use the voltmeter to follow the circuits. mike c. Link to comment Share on other sites More sharing options...
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