1990 SC will start then immediately die

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Worse it wont even start, the person i got it from said it had been sitting for 6 months. which pin on the crank connector do i put the test light on to see if the crank is sending correct signal?
 
Good evening

Have you checked the MAS sensor? Unplug electrical connector and remove the two safety torque screws to check the MAF sensor hot and cold wires for dirt coating. Wires should be shiny. Use an approve cleaner. Disconnect battery to clear memory (15 minutes) and restart.
 
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Yes I see the MAF sensor was replaced in post #1.



Have you checked the following:

1. The PCV tube driver side valve cover to intake duct and the "Y" hard line to the PCV passenger side valve cover.
2. The cam/crank sensor harness for chaffing against the supercharger belt.
3. The ICRM connector for corrosion/security.
4. The engine harness ground driver side back of the cylinder head for any corrosion/security.
5. The driver side battery ground at the engine mount and at the radiator support.
6. Fuel pressure at start and shutdown.
7. DIS harness connectors. Exposed wiring and or corrosion. Missing shielding wire connectors.
 
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Yep I’ve checked all those things, other people are saying the due to the no injector pulse would be the crank sensor or main ECM, Is there a way I can test the crank sensor while still in the car with a test light or multimeter?
 
Yep I’ve checked all those things, other people are saying the due to the no injector pulse would be the crank sensor or main ECM, Is there a way I can test the crank sensor while still in the car with a test light or multimeter?

Absolutely, but not with a meter because the pulses are so short. You need an LED test light, or you could probably jerry rig something with a noid light and some alligator clips.

Look for the "dis no-start" troubleshooting steps used by Ford posted all over this sight. Do a search and you'll find dozens of links to it. I'd upload it here but I'm replying on my phone. When I went through the steps for my no start condition it didn't solve the problem because mine was fuel-related BUT it certainly helped me understand exactly how the engine and all the associated sensors and controls work. One of the steps near the beginning tells you which pin to tap into on the crank sensor plug to test it.

Someone probably already mentioned it, but if your upshift light is on or flickering during cranking, there's a good chance your crank sensor isn't working properly. Not guaranteed as the DIS can cause this too, but definitely start with testing the crank sensor if you're seeing any activity on the upshift light. Also, make sure your battery is well charged and the various grounds, ESPECIALLY the ECM ground on the rad support near the battery, are in good shape and secure.

Keep updating and good luck....

Edit: Looks like someone beat me to it while typing on my phone LOL
 
Solved!!!

Crankshaft sensor is producing no pip signal= bad sensor.

Thank you all for your advice.

Does anybody by chance have a spare good sensor or know anyone that does??
 
Crankshaft sensor is producing no pip signal= bad sensor.

Thank you all for your advice.

Does anybody by chance have a spare good sensor or know anyone that does??


Congrats!

Bill at Super Coupe Performance has a few used ones left...
 
Crankshaft sensor

It might be the Crank sensor. If it is.. it would gets to some point it would even back fires when you rev it up. like the firing timing is out of whack.


I have the same issue. The part is obsolete. Mine has less than 100,000 miles and there it sits in my garage. Does anyone know of any place I could try to find this part? I called Detroit and I'm sol.
 
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