Help! ZR1 NOT STARTING!!!!!!!

[TRU ZR1]

Zr1 not starting!!!!!!!

This is my first corvette but i have been a fanatic ever since i was 6. the zr1 is my dream car but it wont start nowad. so the story starts as i was driving it down the road and when i turned the full power key on and got on it the car cut out and died there was smoke everywhere. i got the car home and discovered that the motor had sucked up about a quart of oil from the cam cover breathers into the intake manifold. i have pulled the manifold and cleaned it out, i have also cranked the motor with no plugs in it to clean the excess oil out of the cylinders and replaced the spark plugs. i put it back together and all it does is crank, i have great spark got plenty of fuel. but my fear is that i have glazed the rings. compression is only 80 in 5 cylinders and 60 in 3 of them. wondering if anybody has had this problem and what they did to fix it. i really dont want to pull the motor and put new rings in it. but if i have to i will. i just want my car back so please let me know of any fixes or if my worst fear has come true.

THANK YOU

GARY BULLINGTON.
Boise, id

 

[Schrade]

Welcome to the boards...

LT5 bores are bulletproof. I think they have nickel sleeves. If your squeeze is low, you probably have a ring problem.

That can be checked with a drop of oil in each cylinder. Pull all the plugs, get a breaker bar on the crank, and spin it with a few drops of oil in each hole, and the comp gauge at each hole. If you get a significantly higher squeeze with oil, it's probably rings.

It should start tho', even with worn rings, unless the plugs are really fouled.

 

[TRU ZR1]

UPDATE. the compression is between 150 and 80 now on the cylinders after is squirted some carb cleaner down them and blew them out and recoated them with a little bit wd40, but i was checking my spark again and i had good spark until i tryed to check 5,6,7,8 then i had no spark. so i checked 1,2,3,4 and they didnt have any spark. i have been checking some of the wiring and i found a pinched ground wire on the back of the block that i am currently fixing. and to also ad, i dont know if this is related but after it stopped running the windshiel wipers dont work:ugh?

thank you for any input.

Gary Bullington
Boise Id

 

[TRU ZR1]

adfixed the grounds that were pinched and still no spark!!!! there is no power to the coil packs and also there is no power to my mirrors and another fuse that says fp. i dont have a manual so i guess its time to buy one, lol. what could be causing these componets to all of a sudden not get any power. i also was wondering where the ignition fuse was located. please help i need my car back i miss it badly

 

[Schrade]

adfixed the grounds that were pinched and still no spark!!!!

If you have 150psi in some holes, and 80 in others, I think you do NOT want fire, although you can still troubleshoot. That is a pretty significant strain on the crank and bearings.

I suggest that you get EXACT squeeze readings for each hole, without any oil, to get a definite condition check of each cylinder. Maybe the only reason you got a 150, and an 80 is because of different amounts of oil for the first check. But, I think you should definitely confirm...

My .02

 

[vigman]

On one of my other projects

( ok BOO HISSS )

I've been busy with a 300ZX TT project...

The engine was wasted... with comp of 85-90 psi... 115 with oil..

and it would fire... but it was a smoke generator...

I would fix the electrical first..

I have no reference info for a ZR-1 ( drool ) so I cannot be much help.

Vig~

 

[TRU ZR1]

heres the compression with out oil. 1- 110, 2- 120, 3- 90, 4- 110, 5-95, 6-152, 7-124, 8-82.
trying to still figure out the electrical problem though.

 

[TRU ZR1]

well i have power going into the ignition module and i have a good ground on the connectors but i have no power going to the coil packs even when cranking it. now does the coil packs see a switched hot when the ignition is on or only when the motor is being cranked. and what sends the signal to the module is it the crank sensor or the cam sensor. i dont want to be throwing parts at it that are not going to fix the problem. please let me know of anything you might think it will be and how to test it.

 

[Hib Halverson]

If you have compression at 80 in one cylinder, 90 in another, 95 in a third and the compression does not come up when you squirt oil in the cylinder, as they say in NASCAR, "Ya done blowed her up."

My guess is you've either bent some valves, broken some rings, fractured some ring lands, cracked a piston or any combination of the above. If any of those are the case, you're looking at an engine overhaul and, done properly, they run from 8,000-12,000 bucks.

With compression numbers like that and which won't come up with oil squirted into the bad cylinders, I think you're wasting your time trying to fix an electrical problem.

There was a comment earlier about the liners being nickel.

Actually, they are Nikasil-plated aluminum liners. Also, the bores are not "bulletproof" as the same post said. The cylinder walls in an LT5 can be damaged in the same way cylinder walls in other engines can be. The Nikasil coating is quite thin and only makes the aluminum hard enough to match, or perhaps modestly exceed cast iron bores in durability. It does not harden them significantly greater than cast iron bores such that their durability would be like steel or hard-chromed cast iron liners. Bottom line, a Nikasil liner will not survive something like, say the end of a broken ring scratching the bore or FOD by ingestion of sand or dirt or...(dare I say it) debris from broken valves.

 

[Schrade]

If you have compression at 80 in one cylinder, 90 in another, 95 in a third and the compression does not come up when you squirt oil in the cylinder, as they say in NASCAR, "Ya done blowed her up."

My guess is you've bent several valves or may have broken some rings. If either's the case, you're looking at an engine overhaul and they run from 8,000-12,000 bucks.

With compression numbers like that and which won't come up with oil squirted into the bad cylinders, I think you're wasting your time trying to fix an electrical problem.

There was a comment earlier about the liners being nickel.

Actually, they are Nikasil-plated aluminum liners. Also, the bores are not "bulletproof" as the same post said. The cylinder walls in an LT5 can be damaged in the same way cylinder walls in other engines can be. The Nikasil coating only makes the aluminum hard enough to match cast iron bores in durability. It does not harden them significantly greater than cast iron bores.

Yeah - I was wrong about the nickel composition statement. 14% silicon carbide, 86% nickel.
:eyerole

"The bullet-proof LT5 engine had proven itself in testing by running at high power levels for hundreds of hours."

-John Heinricy, Corvette Assistant Chief Engineer

But what does Heinricy know. He's just an assistant.

 

[Mac]

Yeah - I was wrong about the nickel composition statement. 14% silicon carbide, 86% nickel.
:eyerole

From the look of things, you're quibbling over details. You said nickel but didn't mention it was a coating. Hib gave the name of the coating but didn't mention the nickel content.

But what does Heinricy know. He's just an assistant.

I've never seen an engine which was incapable of being damaged. I don't think such an engine exists. Calling something bulletproof, whether you're an engineer or an assistant, is just an expression. It isn't meant to be taken literally.

-Mac

 

[KANE]

...you're looking at an engine overhaul and they run from 8,000-12,000 bucks...

hnoes


I can't say as disagree with TRU ZR1 for not wanting to pull the engine.

 

[catbert]

hnoes I can't say as disagree with TRU ZR1 for not wanting to pull the engine.

Nobody WANTS to pull an engine, but that's how this is going to have to go from the sound of it. :cry Opening it up may be the only way to really insure that the diagnosis is correct, let alone the repair. Unless there is a genuine ZR1 guru out there who has been there, done that....

 

[Hib Halverson]

Yeah - I was wrong about the nickel composition statement. 14% silicon carbide, 86% nickel.
:eyerole

But what does Heinricy know. He's just an assistant.

Oh for gosh sake...you've probably never met Heinricy and you're twisting his words.

I've known John since 1984. We've been personal friends since then. Back in 1994, he was the one who got me into the 2nd gen ZR-1 hobby by suggesting I buy one. At the media preview for Chevrolet's 1995 models in the Summer of 94 at Road America, he and I were sitting on the pit wall chatting about the upcoming final year of ZR-1 production. A ZR-1 went flying by and (I'll never forget his words) he paused then said simply, "Hib, you need one of those cars.".

When I visit Detroit, I sometimes stay with John and his Wife. I've interviewed him countless times and gone out for dinner and beers with him about as many times.

What John meant when he said...

"The bullet-proof LT5 engine had proven itself in testing by running at high power levels for hundreds of hours."

...was that, in general, and when properly maintained, the LT5's durability is outstanding. I'll add that, the long time since that statement was made has proven John correct.

That said, what he didn't mean was that the aluminum liners in particular are a significant measure more durable than the walls in a cast iron block, ie: they're not going to survive a broken ring or operation with no air filter. But, yes, Nikasil plated liners will last a long time given proper maintenance and lack of abuse.

The composistion of Nikasil aside, the facts remain 1) the liners are not nickel they are aluminum coated with Nikasil and 2) the engine in question most likely has been damaged and may need to be overhauled.

It is unlikely that any amount of electrical trouble shooting will fix that problem.

Rather than diagnosing a cranks-but-won't-run-issue, I suggest a cylinder leakage test. That will tell a) how bad the problem is and b) what's broken. Once you connect the tester, if you hear a hiss at the exhaust pipes, you've got an exhaust valve problem. If you hear a hiss when you open the throttle plates, you've got an intake valve issue. If you hear a hiss when you listen in the PCV hose coming from the crankcase, you've got a cylinder sealing issue.

 

[vigman]

1st things 1st

I would verify the cam timing BEFORE I tried to light the engine again...

If the cam timing is off ( for whatever reason ) then the engine comes out..

Or at least the heads...

Then you can see what exactly is wrong.....
The compression being that far off per hole and uneven.. is a very BAD sign PLUS sucking all that oil in....

my .02

Vig~

 

[TRU ZR1]

I KNOW THAT I WILL HAVE TO PULL THE MOTOR NOW AND DO A OVERHAUL THATS FINE. BUT IT IS NOT GOING TO DO ME ANYGOOD TO PULL IT AND OVERHAUL IT IF I HAVE NO SPARK WHEN I PUT IT BACK IN. SO I WOULD LIKE TO TRY AND FIGURE OUT WHERE I CAN FIND THE INFO ON TESTING THE CAM AND CRANK SENSOR. LIKE WHAT KIND OF OHMS OR VOLTAGE I SHOULD BE SEEING AND AT WHAT PINS. IF ANYONE CAN HELP ME WITH THIS I WOULD GREATLY APPRECIATE THIS

THANK YOU
GARY BULLINGTON
BOISE, ID

 

[vetteboy86]

This may be a good time to get a Factory Service manual. I'm not sure of their availability due to the ZR1's limited production. Just a thought.

 

[Yoda]

Gary,

I know nothing about the ZR1 other than I would love to have one

Here is website that might help ZR1 Troubleshooting Also a friend of mine from California does most of the work on his ZR1 engine himself.. his log on is ßill shoot him a PM he may be able to give you a few idea’s too

Bud

 

[JimVette]

Go to the ZR-1 registry site. There are a lot of ZR-1 gearheads hang out there. If there is sound advice to be had you will get it there and confirm Hib's answer.

 

[TRU ZR1]

THANK YOU I WILL TRY THAT. I APPRECIATE IT