Will not start when Hot( Vacation starts tomorrow)

tamperproof35

Registered User
I got my a\c repaired and not when the car is hot it will not start. Checked for spark there isn't any.Replaced DIS module & camshaft senor 1 yr ago and crankshaft senor 2yrs ago.Is it one of these or the coil pak.How do I tell which?
 
Year and Auto or Stick.

If Auto does the upshift light flash when cranking?

Do you get a check engine light after a cold start?

Pull the codes for sure even if you don't get a check engine light.

And what do you mean by hot. how hot? Just driving to the store, or after driving 30 minutes to work?
 
Pulled codes got 111 system passed,as far hot meaning operating temp.This is the thing can drive car for 30 mins operates fine,cut it off and it will start back up let it sat for maybe 5mins nothing,will not start.It's a auto 91 year.
 
Well theres nothing wrong electicaly then, it has to be mechanical.
This is a shot in the dark but maybe your fuel filter is dirty. Sometimes they will cause that problem.
 
car starting problems at hot combined with working perfectly other times is usually crank sensor

even though you replaced crank sensor 2 years ago....could still have gone again....could have been misaligned or stress on wires, or crap getting in there.....who knows....

also look for upshift light on when starting....
 
Does the 91 have the 3 digit codes? I thought it was 93 and up?

Next time it does it try this:

Key on, crank, no start.
Key off.
Key on, Crank, no start.
Key off.
Key On, Crank, no start.

Do that a few times and see if it starts. If it does start, then it would be the Cam sensor. With the computer not able to see the cam sensor, it will use the crank sensor and guess. It guesses what cylinder to fire each time you key off, and back on. Eventually it will get it right and the engine will start.

Since it's an auto, you can verify the Crank Sensor function during no start by watching for the Upshift light when the engine is cranking. Normall it should be off. If it's on, that is a signal that the ECM is not receiving a signal from the Crank Sensor.

I'm thinking Cam sensor... but if it totally won't start no matter how many times you do the above process, then it's not cam. Then it might be the crank sensor, or wiring to the crank sensor.

Don't forget to do the #1 test on our SC. Make sure the bolt is still retaining the Harmonic balancer on the car! And with the car running make sure the big pulley on the crank is not wobbling. If you are missing the bolt, or the pulley wobbles, the harmonic balancer needs to be replaced.
 
Thank everyone I think I found it there was a wire running out of the DIS module that the outer casing was screwed up it may have been touching some metal I taped it up "So far it starts every time",(he said hopefully).
 
As you just learned codes do not neccasarily mean a sensor has failed. The codes are telling you that its a problem with that circuit meaning it could be the sensor OR the related wiring.
Always check the wiring before buying new sensors.
Tamperproof35 just saved himself alot of money as well as the frustration of putting a new part on only to find it was a bad wiring connection which cost him NOTHING! to fix.
Glad you got it figure out.:)
 
Mike, when I first got an SC and ran into this sensor problem, Ford (more than 1) told me flat out you can't diagnose the cam or crank sensor problem on codes.
There are a multitude of problems with this car electrically that cannot be diagnosed with codes or their $100,000 test equipment at Ford.

Fortunately now we know that there are "rules of thumb" on the cam and the crank sensor.
 
Actually, you can not diagnose the CRANK sensor on codes. It's failure doesn't cause a code to be set in the computer system. Intermitant failure of the sensor might cause other sensors to throw codes, but the CRANK sensor won't set a code if it isn't working. (the car won't start either).

The CAM sensor will set a code if it fails. But as with all codes in electronicly controled systems, all that setting a code means is that the computer didn't get the expected response from that sensor.

That could mean the sensor failed.
Or it could mean the wire between the sensor and the computer is grounded
Or it could mean the wire between the sensor and the computer has high resistance
Or it could mean the sensor is experiencing odd values due to the failure of another system.
or..
or..

Thus any Dealer mechanic should follow the documented trouble shooting procedure for any car they work on.

And of corse, their procedure includes some tools that without, make it difficult to follow the procedure. For our cars, the biggest help would be the ECM breakout box. It is referenced in all of their troubleshotting guides and greatly simplfies the measuring of voltage and resistance values, and sensor outputs within the wiring system of the car.
 
Well let me recomend some good reading about the EEC-IV system. Take a little time and study how it goes about setting codes and why sometimes it mysteriously doesnt set a code for a particular problem. Theres a reason for that and its not the ECU's fault, its part of the adaptive strategy built into the ECU and oporator error that usually causes that. There are codes for every problem mentioned and if you dont get a code for one of those problems there is a reason for it and its generaly operator error.
George Davenport added this link in the FAQ forum yesterday and there is alot of good info on the system there. Check it out.
www.fordfuelinjection.com :)
 
All that interests me is Dave's easy crank sensor replacement and other "how tos"....

maybe someday someone will make a harness to put the DIS on the fender....which some report is a big improvement....

meanwhile....a considerable amount of human endeavor has gone into making a modern automobile....now with GPS systems....you name it.....but with electrical systems that plain suck.

There is only one way to make a good electrical system like this with sensors and that's to have redundancy so that if a system fails you see the one sensor go...but you still keep driving with a backup system. As far as I know, no such system exists on any car today. At the very least, here in the year 2003 of life on planet earth we should have evolved to that point.

Although I love all my SCs....I would never consider taking one on a long trip because of the possible electrical problems. For that I take the crown vic wagon or sedan, with an extra distributor module I can put in in minutes.
 
Well its obvious that you didnt go to the website and read up on the system. Because if you had you would learn that the system does that to a degree. Its called adaptive strategy.;)
I can only take you to the water I cant make you drink it.:)
Moving the DIS module is simple. I dont understand what the big problem is.:confused:
At that site you can learn in simpler terms how the system works how to troubleshoot it and how to modify it properly.
There are alot of myths out there about the EEC-IV system and that site pretty much lays them to rest.;) But if you dont want to learn you will just have to go on depending on others to point you in the right direction.:rolleyes:
Good luck to you.:)
 
As a matter of fact I did go to the website and I printed it out....
but I'm not going to read it thoroughly just yet....

thought I'd put it in the glove compartment...
It'll make some interesting reading while I'm waiting to be picked up by my wife or AAA the next time I break down....
 
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