WOW! With all this knowledge on how to bring a C5 back from the dead, we could develope a security system that will be KILLER!

 

I'm going to remove my ignition switch and mail it off to Bill to get rebuilt just in case - his thread with pics and instructions is amazing and even though there's nothing currently wrong with mine, I just can't resist sending it off to him! BTW - I haven't seen Bill wrong yet and he gives sound advice

 

Nothing against Mr. Curlee, but that switch can be pulled, disassembled, cleaned, reassembled, and reinstalled in an hour or two by someone who's never done it before. (like me)

The second time took me maybe 30 minutes.

 

I agree 150% and Im Bill!

In not always correct either! I try to limit the times IM wrong!

BC

 

Yep, we knew that, and you do a pretty good job of it.

 

I took the liberty of putting my key w/ 10key chain on it and driving car in to work just now.

With the engine hot--parked--I pulled on those keys, shock the hell out of the whole thing, and wagged them back and forth right and left and down towards bottom, pulling all the way.

The cylinder held and gave me no signs it was going to come loose any time soon. It didn't move at all.

Car is a 2002 w/40kmi; mostly highway; I don't think of it as worn.

This really seems torque related--on track, I could pull more g's without the gremlin acting up by not applying much/any throttle coming out of the corner. It was when I gave it throttle (esp. in 3rd gear) out of a corner that the gremlin showed up. And then, never on the 1st laps, into the session a bit after the car was warm/hot.

I'm still going to track all this stuff down that's been mentioned here but I'm less convinced now it is the switch itself. Maybe the wiring leading to the switch after all is more likely.

 

It doesn't surprise me that you couldn't replicate your problem like that. There's no vibration from the engine, no bumps in the road, etc.

Was the engine running? Did you try my experiment and try to see just how little counterclockwise motion it takes to break that circuit?

 

Yes--engine was idling and operating hot--maybe 200F--not road course hot. Yes, I tried cc motions to break the circuit--I couldn't break it. It takes a substantial torque on the cylinder to turn it at all. Touching the key, it takes a decent amount of force to get it to turn off--it's not something you can do by accident.

Incidently--the inertia effect of left turns pulls the key right. So that does not tend to rotate it CC. What does is when it's pulled right and then suddenly pulled down (groundward)--vertically down will put a little torque on it. I yanked on it though down, right, left and it would not turn off/cylinder move at all by this action.

 

I'm posting this PM from the OP so we can all stay in the loop, since many are contributing.....

Mike,

Is the serial data line the same as the class-II data purple wire? Mechanic says there's this class-II data purple wire that runs all over the car that will pull the HUD and cluster down.

I think this is what he suspects.

He did not pull the ignition switch itself--he pulled the panel down under the column and looked for something amiss in the connectors/wires there and may have moved them around a bit w/car turned on.

I'll have to look at the specs--I'm interested to see if I can find minifuse 19 and the wire running to the ignition switch itself.

Thank you so much for pointing this stuff out,

Andy

Andy, the mechanic is correct in that the class 2 serial buss connects many systems.....and some of the instruments are included...but not all. What is particularly interesting in your case, is that you lose ALL the instrumentation....like the car is off. This is not consistent with a class 2 problem. A class 2 problem will typically manifest itself one of two ways:

1) loss of control of doors, radio,etc.. and instruments go crazy....usually shorting the serial buss
2) no start, or intermittent stalling, communication....usually bad grounding to the PCM causing no communication.

Since you loose EVERYTHING, that tells me you are losing ignition to the instrument cluster, which suggests you have a bigger issue than just a serial data short, ground, etc.

That's why either the 12 volt battery feed to the ignition switch, or the ignition switch itself is suspect.

The ignition switch must be disassembled and the contacts inspected....period.


On a side note, you should fill out your sig.....might bring some local help. You also might consider taking your car to another mechanic. A competent mechanic ,familiar with C5's, should have come to the conclusions already discussed in this thread........

 

Ok, then just humor me. Run the same course without anything else dangling from the key.

I'm telling you, I've seen this happen before.

Pulling the bottom of the key to the right will rotate it counterclockwise.

 

Believe me--I'll never run again w/the keys on the chain. But it will be a while before I have a chance to run on course and it's expensive...I want to fix this before I commit.

 

Ok--that's what I thought you meant in your 1st PM--serial line is the same as class II data then.

I'll look into the manual tonight and see what it takes to get the switch & wiring out on my own. I have looked at the diagrams last winter but at that point I didn't see that the HUD was going down and that the HUD also goes down the same way when you turn the key off.

The puff of smoke is still in play...that was seen by another driver back in the fall and I want to say he thought it was a right front tire...which I also saw smoking at VIR 2 weeks ago as I sat motionsless on the grass...but couldn't get out to inspect.

Another thing I'll try to do is look at your posted diagram and trace down the full path of wiring from the switch to the battery.

With the headers...maybe there's something we just can't see (I've looked with it up on jackstands too--at length!!)

Andy

 

A thought having just looked at this 'switch'. Next to the oil pressure sensor just behind the intake manifold on the driver's side there is a switch that monitors fuel and oil pressure which I believe is essentially a binary (off/on) device. Would an intermittent with this switch or wiring connected to it cause such a problem? I just asked the local Chevy parts dealer what this 'thingie' was for having pulled the intake manifold and I got the above reply. It has three wires coming out of it if I remember correctly. Ken Goodwin

 

What are you talking about? The only sensor next to the OPS is the camshaft position sensor. There is no "switch" that monitors fuel pressure.

 

Right you are, can't rely on everything you're told. But in defense of the dealer's part department, the way I described it, I had the oil pressure sensor reversed with the camshaft position (CMP) sensor which was the initial response. Sorry.

 

Read this post carefully.

rebelhart was not very clear. I will expound.

If you look carefully at the + battery cable where it crosses over top of the frame rail you will find a spot where a sharp edge of metal contacts the battery cable and it possible for this sharp edge to cut into the insulation of the battery cable and ground it out.

If your car has this condition, it is very possible that the stress placed on the chassis during racing causes enough flex in the car to make the battery cable with worn insulation dead short resulting in a dead electrical system.

This could also result in a puff of smoke from the right front tire area.

Inspect your +batt cable very carefully! Look at every inch! Especially where it crosses over the frame rail!

Here is a picture of the suspect area in my car. Mine does not rub, but you can see the standing metal seam that it could rub on. I've seen pictures of guys cars that had that seam cut completely through the cable insulation.

 

GOOD DATA!

I will have to remember this! Yep. ALL TRONS to ground will make a C5 unhappy. When you speak 550 amps to ground,,,,,,you should see visions of LOTS OF SMOKE, SPARKS and NOISE! That damage wont be difficult to find.

BC

 

Since this is a crap shoot, I want to enter the contest and propose that your battery cable going to the starter is in close proximity to your hot headers and has the insulation melted off exposing the bare wires. When you're at the track and all the conditions are just right, your headers short out your battery and kills everything for just and instant. No ignition, no spark, no codes, but a puff of smoke is present due to unburned fuel. Sorry, I don't buy the ignition switch trail.

 

Now that is good info, and it sounds like something we all should go check.

 

Yes this is an issue my porsche 911 had some sort of switch issue from having too many keys in the key ring. The PO was a teacher with lots of keys. I only run with 1 vett key and the house key period.