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Latest update is that there is no spark emanating from the coil to distributor. I'm going to start going through shoebox's testing procedure, if I can correctly match up connectors on the page with real life.
The ICM connector pushes in to the ICM. Hopefully you checked to make sure it was plugged in. Do you have any idea why the other connectors like those in your photo were disconnected?
The ICM connector pushes in to the ICM. Hopefully you checked to make sure it was plugged in. Do you have any idea why the other connectors like those in your photo were disconnected?
Thank you, I do now have a good idea of what I'm looking at.
The IAC plug did check out and that is now connected. The yellow one is weird, as it would seem that there is no way it could stretch down that far. What is puzzling is the fact that according to the 95 diagram, it is coming out of the bundle right at the #8 and #6 injector plugs - right where the Optispark harness wire would be.
I took some more pictures. I found something weird in the harness bundle, but I don't know if it is factory or not. I could not put eyes on the Opti, but I did see four individual wires headed that way.
Comes out right where #6 and #8 injectors do. Cannot reach exhaust. No Opti connector Missing vacuum line? To EVAP cannister? Four wires headed down front of engine. Weird multi-wire junction. Four into one, one being away from ECU.
I think I need to check which Opti I have.
Last edited by It's Cochese!; Sep 18, 2023 at 05:26 PM.
What happened to the car? We’re they parting it out?
I genuinely have no idea. May have been scavenged by the guy I bought it from, he has a shop and buys junk cars and parts most of them out. This one he wanted the exhaust and hood from, and I guess was complete enough to sell as whole.
Or, something happened awhile back where the lack of wire wasn’t noticed while reassembling from a failed Opti, it sat for awhile, and developed the seized motor. Or some other time combination.
I have one that should be here tomorrow. I doubt it will ultimately resolve the issue, but it’s another step.
You're also missing the rubber hose that goes from the top connection on the EVAP Canister Purge Solenoid to the passenger side of the throttle body. It's shown (ar least the solenoid end connection) in the photo I posted of the Opti short harness connector. Hard part to find to replace.
My problem is that as well as I know the the 1994 LT1 (I bought my 94 Formula brand new and kept it for 27.5 years), I no longer have the car so I can’t go out, pop the hood and check the details. Car was also highly modified per the info in my “signature” below.
You're also missing the rubber hose that goes from the top connection on the EVAP Canister Purge Solenoid to the passenger side of the throttle body. It's shown (ar least the solenoid end connection) in the photo I posted of the Opti short harness connector. Hard part to find to replace.
My problem is that as well as I know the the 1994 LT1 (I bought my 94 Formula brand new and kept it for 27.5 years), I no longer have the car so I can’t go out, pop the hood and check the details. Car was also highly modified per the info in my “signature” below.
I need to take a look on the TB as to where this would go, hopefully I can just fab something up easily.
It's just this short piece, right? I would think a short rubber hose might work.
The original part is molded. To make a replacement it’s possible to use a short, straight length of vacuum rated hose, and an 90° angled spark plug boot.
A good reference is the “Shoebox” LT1 info site. That's where I am getting the links I'm posting. He has detailed photos of many of the sensors, connections, etc.. The site has been maintained for more than 20 years and was recognized in a national auto magazine for its excellence. Rob (Shoebox) does drop in here from time to time to help. Like me, he no longer has the 1995 Z28 he used for the photos, how to's, etc. He knows this stuff better than I do.
OK, for my future research needs, this is GM PN 10105324 if I ever find it. I'm going to go check and see if it's just disconnected, or yet another part that was scavenged. Guess I'll just make something like you said.
Ok, so what is going on here? Is this a coolant bypass? Top hose is EGR, bottom hose routes to radiator neck.
Top outlet of TB goes to valve. EGR I assume.
Middle outlet/inlet of TB goes to radiator neck.
Bottom outlet/inlet of TB goes to junction of water pump/radiator line.
Steam pipe is sitting uncapped
Last edited by It's Cochese!; Sep 19, 2023 at 10:18 AM.
The top hose on the throttle body supplies clean air to the positive crankcase ventilation (PCV) system. It connects to a plastic elbow pushed into a grommet on the back/top of the passenger side valve cover.
The lower connection on the throttle body is for the hose from the EVAP solenoid. Definitely do not want coolant attached there, and if that’s what they did it would certainly explain water getting into the combustion chambers and locking up the engine. On a 93/94 you pull the two hoses off the connections on the bottom plate of the throttle body and connect them together.
One hose comes in from the heater return line, see hose clamp labeled 6.
