I'm Lost

[firethorn]

I have a 1998 1/2 ton with the 4.3L and standard trans. When going down the road with one of my dogs in the truck she jumped on my lap while making s shift missed the shift and the engine really whined out. Now the timing does not appear right. Doesn't seem to miss just like the timing is really off. Any ideas?

[Silverado4x4]

Have someone check your timing but I dont see how reving high could do this as the over rev would kick and limit the rpm's to prevent damage to the engine.

[03GMCz714x4]

I agree with previous post. Rev limiter should have prevented any damage due to high rev. If you have high mileage then it could be a worn / streched timing chain or belt.

[firethorn]

It have high miles but was running fine until this happen. The high rev would cause the timing chain to stretch?

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If his is a manual, the limiter isn't gonna keep the engine from revving dangerously high, like for example he was going along at 65 and accidentally shifted it back into first. The rev limiter has nothing to do with that type of over revving. If it feels like the timing is off, not sure how that would feel other than lack of power or knocking considering if it's not backfiring or anything else, then take a timing light and check it. Look for codes in the computer also. The question is exactly how high did it rev?

[firethorn]

God I don't know have high it went but was high (I'm 60 and been around a little while). And It is a standard. You know how your engine runs ruff at idle while it's not time properly, that how it feels. When this happened I had to get it home and it seem the faster on the freeway I went the smoother it ran but slow down and you can feel the ruff idle.

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You can always check your plugs. Sounds like it's skipping a cylinder now then. I don't even know if the timing on that truck is user adjustable like the older trucks were.

[firethorn]

You are right, for the 4.3L there is no adjustment for the dist. I did replace the plugs but still runs the same.

[Silverado4x4]

If his is a manual, the limiter isn't gonna keep the engine from revving dangerously high, like for example he was going along at 65 and accidentally shifted it back into first. The rev limiter has nothing to do with that type of over revving. If it feels like the timing is off, not sure how that would feel other than lack of power or knocking considering if it's not backfiring or anything else, then take a timing light and check it. Look for codes in the computer also. The question is exactly how high did it rev?

 

He didnt go to a lower gear he missed a shift so he was in netural when the engine reved so the limiter kicked in if he got that high in RPM'S. Factory rev limiters are set well below the mechanical rev limit of the engine.

 

It is possible you may have jumped a tooth on the timing gear, do a compression test if it jumped the compression will be way off.

[[email protected]]

If his is a manual, the limiter isn't gonna keep the engine from revving dangerously high, like for example he was going along at 65 and accidentally shifted it back into first. The rev limiter has nothing to do with that type of over revving. If it feels like the timing is off, not sure how that would feel other than lack of power or knocking considering if it's not backfiring or anything else, then take a timing light and check it. Look for codes in the computer also. The question is exactly how high did it rev?

 

He didnt go to a lower gear he missed a shift so he was in netural when the engine reved so the limiter kicked in if he got that high in RPM'S. Factory rev limiters are set well below the mechanical rev limit of the engine.

 

It is possible you may have jumped a tooth on the timing gear, do a compression test if it jumped the compression will be way off.

 

 

True, I thought he said he got the wrong gear. Scratch the earlier post.

[jro909]

strange, i did that a few times on my 4.3 with no side effetcs

[firethorn]

Thanks for all of your commits. I had to take it to the repair shop. Timing is fine, the vib. appears to be coming from somewhere else. Looking at that today.

[firethorn]

Pressure plate had a couple of straps that broke. Just fixed and it drives nice again.

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Pressure plate? Straps? Edit: oh, we're talking about a manual, I forgot. Damn they had to pull the tranny?

[Wingnut]

That sounds like an odd thing to happen due to an over-rev.

 

But...Glad you got it taken care of