Is there any way of finding out what pistons and rods are in an engine without complete disassembly? I'm not really talking brand but something along the lines of 'is this better than stock'? While messing in the drivers side foot well I noticed there was a button switch wired in under the go-fast pedal. At full throttle it trips the switch. I can't think of any reason to have a button set up to go at full throttle unless my car used to run nitrous.
Can anything useful be told with compression psi's?

 

You could pull the heads off, to see the pistons, not a quick process though.

 

can you contact the previous owner?

 

It could be a swithc that shuts off the a/c pump clutch. My brother has a similar set up on his LS1 (only his is a micro swith on the throttle linkage at the throttle body). The only problem is when you let off the gas at 6000 rpm, the pump re-engages and blows up. It seems it can handle spinning up to 6000, but if you just engage the clutch at 6000 it blows up the a/c pump, kind of like side stepping the clutch at 6000 does to the u-joints.

 

I wish I knew how. I got the car from a dealer. Do names show up on carfax? I don't think they do.

GTA - Could be but I've never seen a factory job look so amateur. It had a tab going to the fuse box (was bent around one of the fuse tabs) and it had store bought connectors on it.

 

It could be a few things. Does your car have a TH400 in it? It could be a kickdown switch for a TH400. Does your car still have the ECM in it? It could be an attempt at a TC lockup switch disenguagement device.

 

I have the 700r4 and the tcc still works.
yes the ecm is still in the car and working.

 

I thought I remember reading somewhere that the ECM already disengages the compressor clutch at full throttle. Am I wrong?

As for the switch under your pedal...are there anymore wires other than the one that goes to the fuse block? If not then there's no telling what it was used for. A few months ago I found a rocker switch wired under my dash and after investigating it, it was wired in to the ignition switch. If the switch was flipped, the car wouldn't start. I guess a previous owner felt the need to install it. You never know what kind of crap has been done to these cars in the past.

 

I must clear up my last post. I didn't mean to imply that the switch would be factory, I kind of figured that it would be a home job. As for the ecm turning off the a/c pump, mine stays engaged at WOT. Since my brother has the LS1 in an 87 IROC, the LS1 brain needed to be re-burned to disable the VATS. When he got the LS1 running in his car (Painless did not have a harness available yet when he did it so he used the factory harness) his a/c pump did not turn off at WOT, so he wired up a micro switch on the throttle body to accomplish that. I don't think that they are supposed to shut off the a/c pump at WOT, or people would be blowing up a/c pumps left & right.
Viprklr-try starting your car, turn the a/c on and have some one push that button and see if it turns off the a/c. If it don't, see if it does anything under the hood. I don't know what else it could be. You would figure that if you had NAAAWWWWS you'd want to be able to tap into it anytime, not just at WOT. Curious. Maybe it turns your car INVISIBLE to the police, or activates the flux-capacitor for time travel. :lala:

 

how about tracing the wires??
there isn't a blue bottle in the trunk is there............

 

Look around under the back of the car for holes where there may have been a nitrous line exiting the passenger compartment. Also look for holes from bottle mounting screws.

 

lol, wouldn't THAT surprise ya.


"Wow, I've got nitrous."

 

Other than the wire going to the fuse box there was another that dead ended under the center console. I also found a rocker switch with wires under the center console. I figured that one to be for a sub box or something.
I'll look around for some bottle mounting holes. Aren't they normally mounted through the bottom of the car?
Can't try the a/c suggestion. My a/c is outta there.

You know I always wondered why I found an NOS sticker under the carpet. j/k

 

The ideal place to mount an N2O system in the car is the rear fender wells, either pull the spare tire or hide it under the rear storage compartment. Not too mant places to hide things in these cars. Who knows you might find the hold down straps still in place, most people dont bother to take them out.

 

Many, if not most, Nitrous sytems are installed to work at wot only. Most sytems have a swiotch that is wired by the throttle linkage. Not that Im saying thats what the switch is for, just clearing something up.