1993 3.0L Taurus GL - Intermitent no start problem?

[cfrank2]

I am having a problem with my '93 taurus. Most of the time it starts up and runs just fine but when i turn it off and get back in and try to start it after a short time like going to the store or anything else, sometimes it will crank but not start. I have had the same problem with my 2001 mustang gt and that turned out to be a bad camshaft position sensor. But i tried a full tune up and still got the same problem. I tried a new distributor and still had the same problem, the distributor had a pick-up coil (cam position sensor) already on it so when i had the same problem i assumed that the pick-up coil was not the problem. What could be going on with my car?

Any help is greatly appreciated, Thanks!

[thisnametooktolong]

could be a bad temp sensor

[shorod]

Your symptoms are consistent with a dying fuel pump. Do you have a fuel pressure gauge that you can keep with you to measure the fuel pressure some time when it won't start? That would tell you a whole lot in a short time.

-Rod

[cfrank2]

Originally Posted by shorod

Your symptoms are consistent with a dying fuel pump. Do you have a fuel pressure gauge that you can keep with you to measure the fuel pressure some time when it won't start? That would tell you a whole lot in a short time.

-Rod

I know these cars are well known for fuel pump problems but i just checked today to make sure i was getting spark and fuel. I have fuel supply but no spark. So i checked the ignition coil that i just replaced and it is not getting it's 12V supply when the no-start problem happens, So could i have some kind of intermittent problem with the ignitions switch or a wiring problem?

[shorod]

According to the wiring diagram, the coil and ignition module (pin 4) get power in parallel with one another. At both devices it's through the Red/Light Green wire. This same circuit provides power to the Constant Control Relay Module (CCRM - pin 13) through a wire of the same color. Power to this circuit is sourced through a 10 amp 'Ignition Coil' fuse in the Engine Compartment Fuse Box and power to the fuse is through the ignition switch in the Run and Start positions. This circuit enables the CCRM "PCM Power Relay Enable." If you were not getting voltage to the Red/Lt. Green wire, I don't think you'd be getting fuel pump power either. Of course the fuel pressure you're seeing may be residual from when the engine was shut off. Are you getting pulse to the fuel injectors during the no-start condition?

I'd suggest checking for voltage at both sides of the fuse as well as at the CCRM next time it won't start.

-Rod

[cfrank2]

Originally Posted by shorod

According to the wiring diagram, the coil and ignition module (pin 4) get power in parallel with one another. At both devices it's through the Red/Light Green wire. This same circuit provides power to the Constant Control Relay Module (CCRM - pin 13) through a wire of the same color. Power to this circuit is sourced through a 10 amp 'Ignition Coil' fuse in the Engine Compartment Fuse Box and power to the fuse is through the ignition switch in the Run and Start positions. This circuit enables the CCRM "PCM Power Relay Enable." If you were not getting voltage to the Red/Lt. Green wire, I don't think you'd be getting fuel pump power either. Of course the fuel pressure you're seeing may be residual from when the engine was shut off. Are you getting pulse to the fuel injectors during the no-start condition?

I'd suggest checking for voltage at both sides of the fuse as well as at the CCRM next time it won't start.

-Rod

I will do that, if it turns out that i am not getting voltage what would you think the problem is?

[shorod]

That will depend on where you have voltage and where you don't. If you have it to the fuse and not out, then obviously the fuse or its holder would be the problem. If you have it at the CCRM but not the ignition module, then there is a wiring issue, etc.

-Rod