Assuming this is a Mk3 Turbo - Look on the passenger side, front part of the head. There should be a device protruding out of the head, w/a round-ish black plastic cover. There should be a bundle of wires coming out of it. Jiggle the wires a little bit, follow them to their connector (should be a few inches) and toy with it a bit, make sure it's connected. Try cranking. Do this a couple of times. If this makes it start, you need to replace the wiring on your Cam Position Sensor.

 

Yes, it's an Mk3 turbo... '87.
Thanks for the help. That however didn't seem to be the fix. In poking around with the wires though, I noticed that there was 1 screw (the top screw) missing and the black casing was actually cracked. I'm assuming now that it's gotten water and dirt inside of it. The wires appeard to be connected securely, but even so, does it sound like I just need a new cam position sensor?
I'll start my ebay search I guess... if you think it might be something else, let me know!

Thank you

 

Yes, it's an Mk3 turbo... '87.
Thanks for the help. That however didn't seem to be the fix. In poking around with the wires though, I noticed that there was 1 screw (the top screw) missing and the black casing was actually cracked. I'm assuming now that it's gotten water and dirt inside of it. The wires appeard to be connected securely, but even so, does it sound like I just need a new cam position sensor?
I'll start my ebay search I guess... if you think it might be something else, let me know!

Thank you

It could be that, but it's kind of unlikely. The CPS runs on a magnetic switch mechanism (effectively) a little fluid in there wouldn't likely kill it and many people run without the cover even being on. Have you checked for spark and fuel?

 

No, I haven't checked yet. I thought being that the problem for some time now was intermittent I was sure to have spark/fuel. I don't really know what's involved with vapor lock, but I've heard the term thrown around here and there... could that be the problem?

 

Vapor Lock applied to carbeurated vehicles, on our EFI cars it's not an issue anymore.

Definition: When gasoline overheats and boils inside the carburetor bowl or fuel pump of a hot engine, it ceases to flow. This can cause stalling or hard starting. This is called vapor lock, and it usually happens during hot weather.

I'm thinking it's either a worn component or wiring. For now, confirm you have both spark and fuel, your findings there will decided what line of diagnostics to proceed down.

 

Believe it or not, and embarrassingly, I think I've figured it out... corroded positive battery terminal and connectors.
I'll find out for sure tomorrow morning when I go to start it after it sits over night.
Thanks for the help though.

 

Still no luck...

Alright... still having the same problems. Cleaning off the battery must have been a coincidence. I'm going to check to make sure I have a good ground connection. Other than that, I'm stumped again.
It's almost guaranteed now that if I drive long enough to heat the engine up, it won't start until it sits for a good while to cool down. It always starts if the engine is cool.
I'm not having any overheating problems... I had the head gasket replaced 14 mos. ago.

I'm wondering if this has something to do with the alarm system. There's also an aftermarket kill switch underneath the glove box. Maybe that's something to do with it. It just doesn't make sense to me.

Any other ideas?

 

heat soak maybe? could be wrong....

 

Have you tried replacing the starter?

 

I looked into the 'heat soak' topic and found several past posting on that problem. My symptoms are similar to the heat soak guys, but the strange thing with mine is that when I jump my car (when it's not starting), it starts right away.
The heat soak problem (at least from what I read) sounds totally unrelated to electrical issues. I'm thinking now that I've got some relay that is failing or has failed.

In response to Jeeves starter question... no, I haven't replaced the starter... it seems to turnover just fine. However, it may make a slightly different sound when the problem is occuring... like the engine turns over faster.

But again, the car starts every morning and every night on my way to/from work... it's when I make side trips and turn the car off and then try to turn it back on after a short time.

UGH!

I called 'Sound Performance' in Bloomingdale, IL where I had my head gasket/valves replaced/rebuilt.... they told me to call back during the week. I'll let you know what comes of that if nobody else can think of anything.

Thanks

 

Also... I check my ground, and it's fine.

 

This is not sounding like a starter issue. If it was the engine would not turn over. This is sounding like a fuel/spark issue. It could be the coil packs or the fuel pump relay. Both of them sit in the engine bay.

I had a problem like this on my old 280Z. The starter relay sits on the inner fender well. After a long drive the car had to sit for an hour so that the old relay could cool down enough to trigger the starter. Something similar may be happening to your coil packs or fuel pump relay. With the engine hot I would check for spark and listen for the fuel pump.

 

Have you tried checking the battery for discharge,corrosions,frayed wires,etc.?

 

I'm wondering if the solenoid's not kicking the starter in, and it's just sitting there spinning, hence it sounds different.

 

Many changes later... still same old problem. Replaced the CPS, battery, coil packs, igniter pack, fuel pump relay, ECU, insulated the wiring harness, reset the ECU, checked ground...

Is there a crankshaft position sensor on this car? Someone unfamiliar to the mk3 recommended I check the crankshaft position sensor. Again, I've already replaced the cam position sensor, but if a crankshaft position sensor exists, then maybe that's something to look at.

Thanks

 

Those two are similiar terms for the same type of device. In this case, we only have a CPS.

I personally still wonder about the starter, but again, I can't hear/see what you're running into.

 

I suppose you may be right... the only way I can see the starter being the problem though is if somehow the starter is telling the ECU not to spark... too hot, not enough voltage, etc. Something to check anyway.
Thanks

 

My issue is that you say it sounds different. I have no explaination for why it would sound different.