87 2.5 no spark

[thejim42]

I just picked up am 87 4cyl 5 speed and it has no spark. Ive tried replacing the coil, the icm, the cps, and the ecu. I still have no spark. Anyone have and ideas?

[Marine1Texas]

It may not need parts but need to check the wiring. I don't know if the 4cyl is got the ground issues like the 4.0 does. I am sure some owners of the 4cyl will chime in.

[thejim42]

what tells the computer to send voltage to the coil for spark?

[Marine1Texas]

CPS

[thejim42]

cps is good. still no spark. fuel pump comes on and i know the injector is firing because i keep getting fuel in the oil. but i have no voltage out of pin 27 at the computer which is ignition output. I also have no voltage on pin 6 which is input from the fuel pump relay. I know the relay is good because the pump comes on. so what is the voltage supposed to be from the fuel pump relay to the computer, and is there any connection or component between the relay and the computer? Where does the relay get its ground from?

[Dzimm]

Go through and check ALL the grounds. Always start with grounds because they usually are your problem. The easiest way to find them is to start at the battery and just start following wires to their destinations and clean every ground you find along the way with a wire brush or sand paper. Replace any super rusty or broken terminals along the way.

[Ωhm]

ECU pin 6 controls the grounding for the FP relay (pin 2(85)). If FP runs and injector is hot, good CPS. ECU pin 27 supplies square wave for ICM. Try reading voltage on a VAC scale while cranking the car. Hold gas pedal to floor, should shut injector off.

[thejim42]

what should my voltage be?

[Ωhm]

I have no voltage value for you. Any reading above 0vac would indicate action on that circuit. Take reading at D2-9, no need to disconnect anything.