P0320: Ignition/Distributor Engine Speed Input Circuit Malfunction. I have a 1998 Mustang GT automatic with about 83,000 miles. About 2 months ago, it started backfiring while running and turned off on me and would not turn back on, so i had to push it home. Since then , it would turn on whenever it wants to and i have replaced the spark plugs, spark plug wires, ignition coils, gas filter and speed sensor. For a couple of days, it was running ok it would just backfire once in a while, then one morning it just would not turn on again. I bought the car just a few months ago and before me, the car was sitting for about 10 years. Now, the car turns on but I would have to keep holding the gas pedal at least a little bit or else it will just idle for a bit and then die. It does not turn on right away either, it takes me a few tries until it does. It weirds me out that it just turns off while idling or when i turn it on and put it on reverse right away to see if i can get it running i only get a few feet before it turns off. Has anyone else experience this problem? please help…I have checked fuel pressure on the rail and it squirts up high so pressure is good. I've also checked spark on the cylinders while cranking the engine and they all spark. Next thing to do is probably replace the crankshaft position sensor but i don't want to keep throwing parts at it and not be the problem. I have also checked the wiring from the crankshaft sensor to the computer and it seems fine.

 

Honestly with that particular code, the crank pos sensor is the most likely culprit.

 

I am going to change the crank position sensor this weekend and see what happens. But I was wondering, doesn't that sensor have its own trouble code?

 

Hey for the crank sensor, if you loosen the ac pump you can pop it in. Dunno how the book says to do it, but after a head gasket change, we pulled the sensor to avoid damaging it and forgot to put it on. That's how I ended up doing it and it didn't take long.

 

Thanks I will keep that in mine. Do i need any special tool?

 

No, but it has been a few years since I had to do it. Most likely 10mm wrench, and if you have one with a ratchet end it will be even better. A socket should be fine though. So I am not sure if it has to completely come off, or just loosen enough to slip the sensor on. You won't have to disconnect anything either(other than taking the drive belt off). Just keep it supported so it doesn't hang if the bolts come out. I know I did it by myself, so if you have buddy to hold the pump up when you screw it back on...things will be easier.

 

so i changed the cks and the problem persists. The car still backfires pretty bad and turns off

 

Does anyone have anymore suggestions

 

I assume you've already checked the air filter to see if it's clean, and cleaned your MAF? Could also be a bad coil giving the crank sensor error, that happened to me and I finally had to take it to a real mechanic. He said crank sensors never go out unless you hit it with something and the problem is usually a coil, which it did turn out to be.

 

yes the air filter is new but no I haven't checked the MAF i should do that next. How do you clean the MAF?I replaced one coil because it was broken by the harness but not the other one.