Takes 10-15 tries to start??

[Steve Myers]

When I go to start my SHO it just turns over and sometimes makes a clunk sound. I'll keep trying it and around the 10-15th time it will fire up and run just fine except the check engine light will come on. Also, sometimes after I get it started the Tach won't work. Other times the tach works just fine. My mechanic is not quite sure what it is after coding it. He thinks it might be ignition module or possibly a wiring problem somewhere. Can anyone help??

 

[Brian685]

If the tach isn't working, I get the feeling that the CPS (Crankshaft Position Sensor) is acting up. I've always heard that if the tach lays flat at Zero as you're cranking... the cps is bad.

Just a thought!

- Brian

 

[Huntervf]

Sounds like a CPS problem to me. The CPS tells the computer what position the crankshaft is in (hence the name crankshaft position sensor). When it doesn't work, your car won't run. Your tach also works off this sensor, so an easy warning sign is your tach not working. Sounds like your CPS is on it's way out...eventually your car won't run at all.

Do a search on the CPS, this topic has been covered WELL. Also, go to http://www.shotimes.com and look under MAINTAINENCE, you'll find a complete description of how to replace the CPS.

 

[Shoman94]

Steve Myers:
When I go to start my SHO it just turns over and sometimes makes a clunk sound. I'll keep trying it and around the 10-15th time it will fire up and run just fine except the check engine light will come on. Also, sometimes after I get it started the Tach won't work. Other times the tach works just fine. My mechanic is not quite sure what it is after coding it. He thinks it might be ignition module or possibly a wiring problem somewhere. Can anyone help??

Well, sir, what are the codes he pulled up?

Even though the CPS is the major failure, the tach signal does pass through the DIS module.

Jason