Sho died on road

[John L. Mickevich]

Driving home, Saturday afternoon from doing errands, the Sho died and I couldn't restart her. The engine turns normally, the tach moves to about 500 rpm's, I can hear the fuel pump kicking in, but no go. I checked the reset button in the trunk, that seemed to be ok also.

A police car pushed me to side street and I called AAA. The mechanic
said the plugs were not firing. He checked the fuses, they seemed to be ok, but by this time it was getting dark. I had the Sho flat bedded to a mechanic
but he won't look at it till Monday and maybe then we can get some codes.

I did a search and I guess there's a few grounding points to check out.
Any ideas?

Thanx,
John

 

[Racer X]

This is a complete shot in the dark, but....

- Unplug low coolant sensor
- Replace blown IGN fuse (under the hood, yes I know you said you checked, but it was dark, so who knows...)
- Make sure coolant level is ok
- ???
- Profit!

I was almost ready to say CPS, but your tach moving while cranking sort of rules that out. Next guess would be DIS, but that's usually a partial failure (2 cyl), and not a complete loss of spark.

 

[John L. Mickevich]

This is a complete shot in the dark, but....

- Unplug low coolant sensor
- Replace blown IGN fuse (under the hood, yes I know you said you checked, but it was dark, so who knows...)
- Make sure coolant level is ok
- ???
- Profit!

I was almost ready to say CPS, but your tach moving while cranking sort of rules that out. Next guess would be DIS, but that's usually a partial failure (2 cyl), and not a complete loss of spark.

Yeah, thanks. We'll check that first thing tomorrow.

John

 

[LOUDSHO92]

It could still be the CPS.

 

[jedhead]

X2 on the CPS. Crankshaft Position Sensor.

Bob

 

[JRA2000TL]

So many no-start SHOs are CPS failures. Have you ever had the car stall out suddenly on you before? If so that's definitely something to check. Also, pull codes to see if anything is stored even if you don't have a CEL on. www.shophoenixproject.com will tell you how to do that.

My old big boss at the dealer once told us the obvious...gasoline engines require fuel, fire, and air. You seem to have a fuel pump priming; have him check the fuel pressure at the schrader valve on the top of the intake. Firing...if you pull a wire and leave it close the the plug while cranking, you can see an arc if it's firing...although that can be kind of dangerous. Air...as long as you're not getting codes for this, it should be fine, MAF will cause a rough idle if it's dirty as will a dirty air filter...but you should be getting air to it.

Again, so many SHOs have CPS failures, I'd check that first. Cam sensors can cause the tach to go crazy IIRC not the CPS. Let us know what you find out.

 

[John L. Mickevich]

It could still be the CPS.

Ok, I just thought that if the tach moved, that the cps was ok.

John

 

[rubydist]

no, if the tach moves that means the cam sensor is okay (or likely okay) but the crank sensor can be bad (which causes no spark) and the tach still moves.

 

[John L. Mickevich]

So many no-start SHOs are CPS failures. Have you ever had the car stall out suddenly on you before? If so that's definitely something to check. Also, pull codes to see if anything is stored even if you don't have a CEL on. www.shophoenixproject.com will tell you how to do that.

My old big boss at the dealer once told us the obvious...gasoline engines require fuel, fire, and air. You seem to have a fuel pump priming; have him check the fuel pressure at the schrader valve on the top of the intake. Firing...if you pull a wire and leave it close the the plug while cranking, you can see an arc if it's firing...although that can be kind of dangerous. Air...as long as you're not getting codes for this, it should be fine, MAF will cause a rough idle if it's dirty as will a dirty air filter...but you should be getting air to it.

Again, so many SHOs have CPS failures, I'd check that first. Cam sensors can cause the tach to go crazy IIRC not the CPS. Let us know what you find out.

I can't remember the last time the Sho stalled, it's been that long ago, but
on route to do my errands, it did hesitate once. Thanks for the listings of things to check. I'll check the fuses though first. But once again, with the tach moving, I thought that meant that the cps was ok. We'll focus on that next.

Thanx,

John

 

[JRA2000TL]

Tach problems and some hard starts = Cam Sensor, Shut off/Stalling problems = Crank Sensor.

 

[John L. Mickevich]

Ok, Monday morning I stopped in to talk with the mechanic and tried to leave with him a listing of possible causes compiled from the forum. He seemed to take offense and said he knew how to diagnose the situation.
No big deal.

Later, in the afternoon, he called and said that it was the the crank sensor and they replaced it with a Ford cps which cost $160. for the part. Things seem to be ok now. Well, thanx again everyone for your responses.

John

 

[ViPER1313]

Just something to think about... usually when the crank position sensor starts to fail, it is because the water pump is leaking.

 

[sperold]

I would be nervous about a mechanic who doesn't welcome advice while troubleshooting.
And, by the way, your super-confident mechanic could have sourced an Airtex/ Wells or Std. Motor Products crank position sensor for half that amount. But he won't welcome that advice either.

 

[.RaMpAgE.]

yea crank sensor or check your ground on the intake just for fun, wouldnt start after i replaced my cps grnd was disconnected lol