Cranks but won't start. No injector pulse maybe?
86 fc3s n/a 52k miles pure stock stored since 2009. I've removed, cleaned, and replaced the tank, new fuel pump, filter, slow hand cranked with oil then new plugs. It has spark at the plug wires and fuel at the top fuel rail. Cold compression is about 60 psi in both rotors. I've checked several electrical things per Haynes, all ok. Pulled the plugs after each cranking and they are dry. It does pop on ether. Why won't the injectors squirt? Or maybe its another problem. Thanks.
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Oh, OK. Before I take the top off the motor to clean the primaries, is there a way to see if electrical pulse occurs in the leads to the injectors? I'm trying to do easy stuff first. Thanks again.
Originally Posted by Mallory2
Oh, OK. Before I take the top off the motor to clean the primaries, is there a way to see if electrical pulse occurs in the leads to the injectors? I'm trying to do easy stuff first. Thanks again.
You could check at the ECU. The pins for the two primary injectors are 3E (Light Green wire) and 3C (Light Green/Black). Place one end of a LED light to one of the pins and the other LED lead to pin 3I and w/key to start the light should flicker. Do the same thing for the other injector pin.
Sometimes the AFM can interfere w/things and you might want to try unplugging it and jumper the fuel check connector and see if the car starts (if it does start do not run the car too long because it will be supplied w/way too much fuel).
Sometimes the AFM can interfere w/things and you might want to try unplugging it and jumper the fuel check connector and see if the car starts (if it does start do not run the car too long because it will be supplied w/way too much fuel).
Excellent answers, thank you very much. Do you think an analog multimeter needle bounce might reliably replace the LED test light? And, er, where is the ECU? (I'm old AND dumb.)
If you have a test light, you can back probe one of the primary injector driver wires with the test light connected to the positive terminal of your battery. You are just watching the PCM pulsing the ground to the injector, so obviously your test light will need to be flashing whilst cranking, that will tell you a lot. The easiest place to do this is at the engine computer itself, under the passenger side carpet, close to the firewall, you'll have to remove the metal cover over the computer to gain access to the connectors. I wish I had a pinout diagram on this computer to post up for you, but I imagine someone has one posted on this forum somewhere.
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jeremyferguson4444
2nd Generation Specific (1986-1992)
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Feb 18, 2016 06:29 PM






