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TB rebuild?


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Good Day All,


I was thinking that I might rebuild my throttle bodies while I was in doing some other repair work. I observed some general clacking when I ran with the tupperware off (could have been plenty of other things). But most notably, my idle air screws (BBS) have always been off when I balance the TB's - guessing maybe a full turn difference between the two. I pulled off the TB's and I cannot discern any radial play on either shaft - certainly some axial play. So now I'm thinking this is not the source of what I presume is some sort of air leak. The stop screws have not been moved from the factory adjustment (original tamper paint).


I just check the BBS's from my last adjustment. The right side was about 1.1 turns from fully seated, while the left side was only only about.2 turns. I always adjust the TB's only after first doing the valves.


I guess I'm just looking for some confirmation that I don't need to mess with the TB rebuild (just yet), and maybe some of you will have suggestions for the cause of my BBS discrepancy. I'm at a relatively low 48K miles.


Thanks much.

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Afternoon Wayne


Even new or almost new TB cams can rattle on the idle stop screws (really means nothing).


If you don't have excess radial movement then no reason to rebuild.


Just make sure that your R/H lower (short) cable has a little slack with choke OFF & engine hot & TB cam on stop screw.


The thing you also need to verify is that: both side TB throttle cams lift of their stop screws at the very same time & hit WOT at the very same time when using the twist grip.

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Thanks DR. That is my routine (slack cables to ensure throttle cams are on the hard stops when balancing idle). When I re-installed the TB's after the top end rebuild, I did my best to ensure the cams moved off the hard stop at the same time. I don't know that I checked at WOT. Will do that when I put it back together. BTW, I had this issue before the rebuild, as well.


Thanks Lee. I did have the injectors serviced while the heads were out for the valve job. Not sure that I noticed much difference. Their report was kinda the same as others have had. Slight imbalance between the two before, and almost perfect after. Oh, and got some pretty pix, too.


The nagging feeling is that I have an air leak somewhere. I'll have to do some "sniffing" when I get it back together.


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