Always stick to the basics, no short cuts....!!!!!

[XfireZ51]

Originally Posted by Ccmano

Yes had the same thought, that this was the cause of some if not all of the tuning peculiarities we were seeing. But boy it ran really well. Too bad we can’t see it run with the issues fixed.
H

Well Hans, we’ll have a more accurate base tune to work off of for this new motor.

[Paul Workman]

Originally Posted by Ccmano

I was somewhat hesitant to post this, because, as you will see, it is really embarrassing for me. My hope is that by posting this it will save someone else from making the same mistake I have recently made.

You're not alone! My (Navy electronics instructor) troubleshooting mentor always stressed: "Never assume. You don't know something to be true until you VERIFY it to be true. He also said, one first has to know exactly how (whatever) works...to be able to determine when it isn't working as it should! Makes sense.

I usually feel confident, being a "wrencher" since high school. But, when in doubt or the least bit puzzled, I often will attempt to pick an experts' brains for their experience and clues to further investigate.

But forget just once, and ol' Murphy (Murphy's Law) seems to be just waiting every time I forget and try to assume something! GOTCHA!!! Then, after being fully chagrined, I'm going back to the basics...like I knew I should have in the first place.

Well...no teacher like experience. Serendipity is a good thing! Your among friends, Hans. And, thanks for posting!!

.

[XfireZ51]

Hans,

Remember.

"He who is without sin can cast the first stone"?

Jesus was prescient and was actually prognosticating about working on the LT5 when he uttered these words.

[Wigert]

Thanks for sharing! My Z is using tons of oil so this would be something for me to look into. Is the only way to see the problem by removing the injector housing? Can it be done with the engine still in the car?

Sorry for any stupid questions...

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[XfireZ51]

Originally Posted by Wigert

Thanks for sharing! My Z is using tons of oil so this would be something for me to look into. Is the only way to see the problem by removing the injector housing? Can it be done with the engine still in the car?

Sorry for any stupid questions...

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First thing is to look at plugs. There is no need to pull motor for a check of IH gaskets. Just part of doing the top end.

[Ccmano]

Originally Posted by Wigert

Thanks for sharing! My Z is using tons of oil so this would be something for me to look into. Is the only way to see the problem by removing the injector housing? Can it be done with the engine still in the car?

Sorry for any stupid questions...

Skickat från min GEM-701L via Tapatalk

The plugs will give you an indication of where the issue is. (Which cylinders are most affected) Then there is no way around it. The plenum, fuel rail with injectors and injector housings have to come out. This can all be done with the engine in the car. A fairly straight forward process. If you do go in plan on doing both sides.

Good luck, hopefully my error helps you out. How many miles on your car? I suspect this is a high mile thing.
H

[Wigert]

Originally Posted by Ccmano

The plugs will give you an indication of where the issue is. (Which cylinders are most affected) Then there is no way around it. The plenum, fuel rail with injectors and injector housings have to come out. This can all be done with the engine in the car. A fairly straight forward process. If you do go in plan on doing both sides.

Good luck, hopefully my error helps you out. How many miles on your car? I suspect this is a high mile thing.
H

Thanks for the feedback! My Z is a 1990 with 7700 miles on it, which is not that much. But if I go highway 15 miles it drinks a quart of oil. I have read some of the posts regarding exhaust seal, which I lack and maybe that is a reason. There does not seem to be any blue smoke but if I hold a paper towel behind the exhaust and someone gives is some gas the towel becomes very black...

I have just changed the PVC lines (to Jerry's) in case that is related to the issue. The previous owner had done a strange connection from the top of the PCV valves and the bottom line had been pinched somewhat. Havent driven the Z since the update but it feels like there is a bigger issue.

I have not noticed any noticable oil leak either until just recently. Something I am looking into as well.

Sorry for the long post! Ill need till check the plugs as you suggested.

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[Ccmano]

With only 7700 miles I seriously doubt you have the same issue. With mileage that low I wonder if the rings have properly seated. I would do a compression and leak down test.
H

[Wigert]

Originally Posted by Ccmano

With only 7700 miles I seriously doubt you have the same issue. With mileage that low I wonder if the rings have properly seated. I would do a compression and leak down test.
H

Okay good to know. A compression test is a good idea and probably the best way forward. I will do it when spring arrives.

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[5ABI VT]

wow thanks for sharing. Very interesting I wonder if this may have been the issue with many cars I have seen threads about oil consumption etc. What did the plugs look like?