TB removal and then some!!!

[HAWAIIZR-1]

Congratulations Tom and great job with this project. Thanks for taking time to document and share. I'm sure you'll find a new project soon and I can't wait to follow along and I'll be a sponge sucking up this info.


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[gtcollins@maxnet.co.nz]

Hi Tom great to see it going again awesome to see it idling at the correct speed also good that you are happy with it

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[Roadster]

Originally Posted by HAWAIIZR-1

Congratulations Tom and great job with this project. Thanks for taking time to document and share. I'm sure you'll find a new project soon and I can't wait to follow along and I'll be a sponge sucking up this info.


Sent from my iPhone using ZR-1 Net Registry

Glad you are enjoying the thread Craig, still more to do with the minor adjustments. Always projects going on, never ending.....

Originally Posted by gtcollins@maxnet.co.nz

Hi Tom great to see it going again awesome to see it idling at the correct speed also good that you are happy with it

Sent from my SM-G930F using ZR-1 Net Registry mobile app

Hello and thanks Glen, yes very happy with the idle speed but as mentioned above and previous posts, just maybe another minor tweak or two, to keep those IAC's in an acceptable range. If I get them to stay up above a 10 count or higher during idle on a consistent basis, I will be satisfied......

[tnova]

I've been following the posts closely as I'm rebuilding my LT5 (160k miles) to with GVD full porting including the TB. I'll have to go through the idle setting. Short block is done, waiting on the top end but not rushing. Thanks.
Tony

[Roadster]

Originally Posted by tnova

I've been following the posts closely as I'm rebuilding my LT5 (160k miles) to with GVD full porting including the TB. I'll have to go through the idle setting. Short block is done, waiting on the top end but not rushing. Thanks.
Tony

Tony, glad the posts may help you out. On the idle issue from what I have learned from reading and relayed by phone conversations is to let the engine warm up fully to operating temps in Closed Loop. Check your IAC's and TPS settings. It would also be good to have access to a Tech 1 or similar scanning device. After fully warmed up check your IAC counts at idle to see where they fall and also check your idle. If your counts and idle are within the range, then go far a test drive and do multiple stops and starts making sure you come to full complete stops for more than a few seconds. Each time you come to a complete stop, check where your IAC counts are and what your idle is doing. If you need to make adjustments to bring your IAC counts up, you will need to turn the min-air adjustment screw counter clockwise (which will close the primary blade more) ever, ever so very slightly for each adjustment you do. Blip the throttle and let the idle settle down for a few, and then set your TPS to .54v, again blip the throttle and let everything settle down. Then what I feel is the most important item, is to go for a test drive like you previously did and follow the same procedure as you did before. Come back and take your readings again, make any adjustments
that you need to do to get your counts in range.
If your idle is higher than it should be, then you may have a different or additional problem that will need to be addressed.
Most of you probably already know this, but I thought I would post what is working for me. This has been quite a learning experience for me and I very much appreciate the certain individual who has educated me through this during this time.

[tnova]

Thanks. I've got a Tech 1 and will be following the procedure you provided.
Tony

[Ccmano]

Originally Posted by tnova

I've been following the posts closely as I'm rebuilding my LT5 (160k miles) to with GVD full porting including the TB. I'll have to go through the idle setting. Short block is done, waiting on the top end but not rushing. Thanks.
Tony

Not to hijack the thread, Tony why did u decide to rebuild at 160k miles? Mine is at 181k but compression is strong. Other than possible chain stretch is see no reason to rebuild just yet.
H

[tnova]

Agree, the LT5 is a stout high mileage engine. However I don't think the previous owner cared well for the car. I had excessive oil consumption, even for an LT5, and barely got through CA smog after 4 tries last time-probably the oil blow by. All the liners were out of specs and a few had fingernail snagging scratches so I replaced them all. And who doesn't need more power!
Tony

[Ccmano]

Originally Posted by tnova

Agree, the LT5 is a stout high mileage engine. However I don't think the previous owner cared well for the car. I had excessive oil consumption, even for an LT5, and barely got through CA smog after 4 tries last time-probably the oil blow by. All the liners were out of specs and a few had fingernail snagging scratches so I replaced them all. And who doesn't need more power!
Tony

I see. Mine was well cared for. No lower end issues whatsoever. When the time comes I will go for at least a 510 engine. I have a Fidanza/clutch, headers and exhaust going in shortly. Keep us posted on your build.
H

[Roadster]

So last night my throttle was sticking again in the garage later in the night. So opened the throttle all the way and left it like that for the next 15 hours. Also was thinking of what I could do to make the throttle non-sticky. It was operating very smoothly after I took out the plastic inserts. Then I applied a thin coat of White Lithium Grease on the ends of the blades so when they close they would be less sticky. It seems to work well, might have to do a little bit more on the top of the blades.....this is apparently what happens when you don't bake the "dag" in an oven as per instructions. It takes much longer to cure.....

I did do a minor tweak last night on the min-air screw, another counter clock wise turn, a very tiny adjustment. My TPS reads .54v with engine off, but will read .56v with engine running and sometimes will go down to .54v when stopped. The engine does not stall, the idle is where it should be IMO. The IAC's have somewhat stabilized during the stop and go testing, which reads anywhere from 15 to 10 count at a stop and after the second test drive right after the first test drive came down to a 6 count. But that 6 count was a result of me turning the AC on and off multiple times, so it may not have had time to stabilize.
Everything is where it is going to be, I could be splitting hairs forever trying to get the perfect balance. So I am very satisfied with the results, the only other tweak would be to the throttle blades again, with the white grease.
And my idle was in range with the desired idle reading of 662 rpm's when fully warmed up in Closed Loop. It could go as low as 637 r's or as high as 675 r's. And this does need repeating, at no time did the idle ever go up to the 900-1100 rpm range as before when I was having that problem. That alone is worth everything that was done with this plenum pull. With the corrections made and a lot of luck....lol, it is a very satisfying feeling!!!
Other than that, it's a done deal.......

keeping the throttle blades open all night and most of the day...

one of my readings during a complete stop....

TPS reading with engine running at a complete stop....

TPS reading with engine off and sometimes running at a complete stop...

Throttle opens to 100% with engine not running...

my last IAC count reading with engine idling after the second test drive for today.....and multiple AC on and off tests...