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420A Turns over but won't start... 420a

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Probationary Member
Feb 6, 2012
Kingston, Tennessee
This all started when my radiator cracked and caused my '96 420a to overheat. One of my buddies suggested that it might be vapor locked but it turns out thats not the case, at least he doesnt think so anymore. I personally dont know all the much about vapor lock. So...

I opened the schrader valve on the fuel rail to make sure i had fuel pressure and got a nice money shot of fuel LOL. Havent checked injectors...

Checked voltage on the black/red wire going to the coil and its getting ~8 volts. Im about to check the coil to see if its bad, but any suggestions/help would be awesome.

Thanks in advance...
U need fuel, air and spark to run.... Grab a plug put it in a wire lay on valve cover and have ya buddie turn over the car, if u see spark u r good, if not chech cap roter ect.... If u do, pull you plugs see if they have fuel on them.... Just an idea or 2 to get ya started
I had this happen to mine too... Stomp your pedal to the floor and hold it there while you crank it. Try this for a solid 5 secs with a second or two interval. If you do this for more than 30 seconds and no start, don't try it anymore. You will fry your starter.
Could my cam position sensor cause this? I know i got my head pretty Fn hot when it overheated, im just thinkin that maybe it fried the CamPS.

Correct my if im wrong but, the PCM bases the timing off of the CamPS and the CrnkPS right? Anyways, im gonna go check that...
Try what I just told you to do man, I'm telling you mine does this. Tricky to start. If you can't get it started that way then try to get into it. Trust me I have the 420a too, I think this is more common then you think.
well, that was a no go...

im about to check my cam pos sensor and in my haynes book its telling me to check the voltage going to the crank sensor from the PCM. any idea why it would tell me to do that?
So, first things first. You need Spark, Fuel, Air. Air is given to you, so you need to move on to Fuel & Spark. You have stated that you have Fuel so there is nothing left, but Spark. You did overheat your car, so do a (compression test) to see what the condition of the engine is internally. How (hot) did it get? If anything it would have been along the lines of (vapor lock), then you would have a BHG & Hdyro-lock it for good. Do not think this is the case, maybe.

Moving on to the "No-start". You move back from (Ign. coil) back, check the harness side to see if you are getting power to it.

Checking the (CMP) Sensor, if you believe that is the problem/ you can at the least eliminate it could be that.

1. Ign switch "ON", check at #1. & "ground" should be between 8-9 volts.
2. #3. & "ground" should be 5-5.5 volts.

To answer you question, you are testing the harness side to ensure that the (sensor) is getting power to it.

My advice is first, check to see if you have any OBD II codes, double check with a scan even if the light is not on. The ECM should have something on it causing the NO-START.....
already checked the trouble codes, but the cam pos sensor's signal output voltage is very low. not even one volt. when i crank the engine, the voltage varies inbetween 0-0.3 volts, instead of the 0.4-3 volts that the haynes/chilton book says is normal.

and yes, the coil is getting around 12 volts
whats the easiest way to see if an injector is moving any fuel? just to pop it out and crank the engine im guessing?
So your car ran then the radiator cracked and you overheated. So you replace the radiator, and now it won't start?

My guess is that you may have jacked up your head gasket. When you have an issue like this, it's typically due to whatever happened out of the ordinary.

Pop off you radiator cap and crank the car over. When you do that, if it shoots out coolant you will know that your head gasket is junk. Or do compression test.

But my honest opinion is this is directly related to and cause by you overheating.
So if your head gasket if jacked will that also cause it not to start cuz I'm having the same problem with my 98 eclipse gs
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