An enigma insues...

[Kb7tif]

Cam Timing?

[XfireZ51]

Originally Posted by Kb7tif

Cam Timing?

Since we know who did it, an impossibility!

[rhipsher]

Originally Posted by XfireZ51

He's checked that several times. Not plug wires. May not be that simple.

Really? I did'nt read anywhere in this thread that he'd checked the fireing order of the pluge wires. It's an easy mistake to make. I hope you geniuses get it figured out for Pauls sake. I feel your pain Paul. Hope you get it running right buddy.

[Pete]

We will fix her or my name isn't Pete

Pete

[Paul Workman]

Originally Posted by rhipsher

Really? I did'nt read anywhere in this thread that he'd checked the fireing order of the pluge wires. It's an easy mistake to make. I hope you geniuses get it figured out for Pauls sake. I feel your pain Paul. Hope you get it running right buddy.

I suspect by now this wasn't the ol girl's first dance - one melted valve and one bent one was discovered on the initial head- work. Perspective: My other hobby is competition rifle shooting. Even after 45 years of handloading, machining cases to exact specifications, weighing bullets, powders, primers, spinning bullets to check for internal concentricity, lead lengths, throat angles, seating depth, bedding, Jewell triggers, rebuilding triggers...even then sometimes something comes out of left field. And, so it is with LT5s. If it is what we think it is, I can tell you I ain't the first this has happened to: it haz happened to some of the best in the biz (so I'm in good company!)

It "could be this and it could be that"...I'd rather not speculate until we have the issue "to ground". Once she' running again, at that time we'll write it up: what happened, how to check for it, how to fix it - before going back in the car!

Let's just say it isn't wiring - at least not at the moment. (But! I can now pull my intake plenum in under 15 minutes - and I have the coil-pack wiring memorized!) Hotrodding SBCs was all I knew before the ZR-1. The unfamiliarity with the LT5 engine, coupled with the computer aspect of it - was (for me) intimidating, initially. It still has its mysteries, and I'll be on the learning curve for some time yet. But, as anyone that has followed his wrenches (no, I didn't say "wenches"...Pete) knows, the "shadows" give way to the comfort of familiar territory.

At 7:45AM yesterday morning I took a wrench to my 100% assembled Z. By myself, working off of jack stands (no lift) and cardboard, and all the tools I collected on the first go-round, I had the engine out just after 5PM. The exhaust is up against the wall, trans on a floor jack under the car, clutch over here, plenum over there...looks like a disaster again. Hopefully, once back together, it will be the last time for a while. But, if I have to pull the motor again for some reason, other than the time to do it, it falls into the "no big deal" category; and that's a good thing. I feel like I'm learning about this one of a kind Corvette, and in spite of the setbacks, each has been a learning experience, and it would be a lie to say I wasn't enjoying the learning part at least. However, I wanna drive it so bad I can taste it! So there's that aspect burning in me as well!

Stay "tuned"...

P.

[tomtom72]

J. C. on crutches! I'm hopeful that it is something minor Paul. I can't read this thread and not think...." jez if it can happen to the FBI brain trust...what would I do by myself!??!"

Man I do feel for you....wish I knew the answer as I'd fork it over in a skinny minute. I hope this is not as serious as I think it sounds.

That has got to be some kind of record for pulling an LT5 solo, no?

Here's to this bad dream coming to a speedy conclusion!

Tom

[rhipsher]

With freinds like Pete not far away you'll have it fixed soon. Even if you have to pull the engine again. Hahaha! That would be F'ed up dude. I sorry! I know it's not funny. I'd have to do the same thing and I don't have a guy like Pete to guide me through it like Yoda.

Id have to figure it out as I went along. And Call Corey for help when I needed it.

[bobbyhi]

Paul, think of it this way - with all the experience, you could probably become a new mechanic for Marc....more power to ya buddy!!
get 'er running..

[rhipsher]

The down side to that is Mechanics don't make squat unless your a Ferrari/Porsche mechanic. Unless you think $20 an hour is good money.

[Paul Workman]

Originally Posted by XfireZ51

With no knock counts and no knock retard, why would you suspect knock sensor?

Sorry for the mystery...
Last winter (while you were still on on Pete's garage probation) therein was a discussion about the KS. At one time, Bob G bought a new knock sensor, suppose to be for a '90. However, when firing it up, the engine would hardly run. The ECM was taking out (I think he said) 20* of advance, and it turned out that the knock sensor for the 90 is different from those of later MY LT5s.

The key distinction was the ohms to ground: The 90 knock sensor is approx 98-101kΩ, whereas the KS resistance used on the newer cars is considerably lower (Pete and I measured 3.8kΩ on one such KS).

When I bought my new one, I gave the GM dealer the AC Delco part number that Jerry posted. However, when the parts guy says, "Oh, this is the old AC Delco number. I'll cross-reference it to the "new" number", I became dubious...

So, when my LT5 was running like a box of rocks, and there was no apparent reason for the change, I remembered that conversation about the KS. However, in spite of no knock counts or retard values, I put the old KS back in. But, it made zero difference in the way it ran, and the knock counts and retard values were still zero.

Shoulda 'splained my reasoning better, Dom. Sorry for the cornfuzion!

P.