Throttle coolant block off.

[rhipsher]

It works great in the summer time. But when it starts getting into the 30's not so well. When it gets cold and the aluminum throttle body contracts it causes the butterfly plates to stay open. Get tired of idling at 4000rpm's at the light. Unblocked it and when the hot coolant makes its way back into the throttle body it works like a charm. Luckily or unluckily it doesnt stay cold very long in Texas before that "fry an egg on the sidewalk heat" makes it's way back. I'm going to put a summer/winter valve in line.

[Paul Workman]

It works great in the summer time. But when it starts getting into the 30's not so well. When it gets cold and the aluminum throttle body contracts it causes the butterfly plates to stay open. Get tired of idling at 4000rpm's at the light. Unblocked it and when the hot coolant makes its way back into the throttle body it works like a charm. Luckily or unluckily it doesnt stay cold very long in Texas before that "fry an egg on the sidewalk heat" makes it's way back. I'm going to put a summer/winter valve in line.

Hmmmm.... I'm not having that problem, and I have installed the plugs in the IHs and capped off the coolant line that loops thru the TB from the passenger side. Starts, idles, and runs just fine...28 degrees...no coolant in the TB. Having this discussion w/ Marc H, he and I agreed that once the engine fires, and runs for just a little while, there is plenty of heat under the hood to prevent frosting.

And, after all, these cars were taken to Canada in the dead of winter, something like -30 or -40F, if I recall, and fired them up. At the moment the engines fired, the coolant would be at ambient temp, or waaay below zero. There was no discussion about them having issues like you describe, FWIW.

My point is, if your throttle plates are sticking at +30F, then something needs to be adjusted, methinks. But, just to be sure, I'll fire her up (temps in the low 20s now) and let you know how it goes.

P.

[rhipsher]

Yes my dear Workman! But you've also got to remember I have those 3/8 thick finalic plenum spacers and even after hours of driving my plenum is only luke warm to the touch. And my throttle body is cold to the touch. Those things really work to keep the top end cool. As soon as I unblocked it the throttle body was very warm to the touch and my butterfly valves worked great. Makes perfect sense. Of course iknew that's what the problem was. Just kept forgetting to unblock it.

[xlr8nflorida]

Yes my dear Workman! But you've also got to remember I have those 3/8 thick finalic plenum spacers and even after hours of driving my plenum is only luke warm to the touch. And my throttle body is cold to the touch. Those things really work to keep the top end cool. As soon as I unblocked it the throttle body was very warm to the touch and my butterfly valves worked great. Makes perfect sense. Of course iknew that's what the problem was. Just kept forgetting to unblock it.


Are those spacers to keep motor cooler and not lose HP due to heat soak?

I can't remember who sold those? Do they work?

[rhipsher]

The plenum spacers take the place of the brass plugs cuz they totally block coolant from entering the plenum from the injector housings. So by unblocking the drivers side coolant hose it only allows coolant to flow to the throttle body and back hence keeping the throttle body warm and freely working. If you take a 1.00 piece of aluminum and measure it then hold it tight in your hand for a minute the heat in your hand will cause it to expand .001 of an inch. And when your talking 150 degrees irt will expand even more. Carter will back me up on that so its not unreasonable to see how going from a 98 degree day to a 30 degree day that the aluminum contracting could cause the plates to stick open and not close all the way. I know because I just proved it today by allowing coolant back into the throttle body and that was the end all be all of the problem. Sometimes its just that untechnical.

[carter200]

Rick is very correct on his explaination. Replacing the OEM throttle body plate with my billet plate is worth up to 50hp. The spacers Rick mentioned are a tried and true way to keep heat soak from the plenum.

Rick, it's getting cold here so how about sending some of your heat my way. :dancing

[USAFPILOT]

what plate are we talking about that can get you 50HP? Are you serious?

[Paul Workman]

Yes my dear Workman! But you've also got to remember I have those 3/8 thick finalic plenum spacers and even after hours of driving my plenum is only luke warm to the touch. And my throttle body is cold to the touch. Those things really work to keep the top end cool. As soon as I unblocked it the throttle body was very warm to the touch and my butterfly valves worked great. Makes perfect sense. Of course iknew that's what the problem was. Just kept forgetting to unblock it.

A new wrinkle...In your OP there was no mention of thermal spacers. But, at the moment you first fire it up after a 30 degree soak, the coolant will be close to 30 degrees too, and if, as you say, the problem is binding of the throttle plates due to the cold (not saying your TB isn't doing what it obviously IS), are the plates bound up upon start up??

Again, I refer to the development documentation in "Heart of the Beast" where these LT5s were cranked after cold soaking in temps at least 60 degrees colder than your +30 degree experience...and there was no mention of sticking throttle plates. And, like the HOTB report, I'm not having the problem - even running the Z in the teens (temperature, degrees F)

"I'm just sayin'"...Somethin' ain't raht 'bout your stickin' plates. Temp might be the ingredient that points it out, but if your one example proves removing the bypass will prevent it, then my one example proves it isn't necessary and we have a conundrum.:icon_scra

Anyone else with a bypassed TB having idle issues - with or without a thermal isolator?

P.

[Paul Workman]

Rick is very correct on his explaination. Replacing the OEM throttle body plate with my billet plate is worth up to 50hp. The spacers Rick mentioned are a tried and true way to keep heat soak from the plenum.

Rick, it's getting cold here so how about sending some of your heat my way. :dancing

Using a relative hp vs. air temp (http://www.anycalculator.com/enginehorsepower.htm)(only) calculator, for a 400 hp motor there is a 56 hp difference for intake air variance between 110 degrees and 30 degrees ambient air temp (pressure fixed at 30"Hg and humidity fixed at 50%) Not to get OT, but at WOT I'll wager with or without the spacer the difference in air temp entering from the outside until it enters the IHs is nowhere near the 80 degrees it would take (according to the calculator) to make a 50+ hp change due to intake air temp. I'm not arguing that air temp doesn't make a difference to hp. But, I'm dubious that the spacer in question can directly or indirectly affect intake air temp - especially at WOT - to the extent as to make anywhere close to the 50 hp difference. JMO.

P.

[rhipsher]

Paul it doesn't happen on start up. Only after you push the gas peddle. And im willing to bet that the cars you mention that were started in -60 degrees didn't have the throttle coolant blocked off either so it would of never of happened to them.

[Aurora40]

Paul it doesn't happen on start up. Only after you push the gas peddle. And im willing to bet that the cars you mention that were started in -60 degrees didn't have the throttle coolant blocked off either so it would of never of happened to them.

What he was saying though, is coolant to the TB or not, starting an engine that's been sitting overnight in the cold, it would exhibit the same problem when you drive away (dunno about you, but my coolant doesn't warm up in 20 seconds) if this were in fact a normal issue. -60 degree coolant isn't going to warm up a -60 degree throttle body.

I have to agree with Paul, that does not sound like a normal issue. However, if hooking the TB coolant line back up works and is easy for you, it sounds like a satisfactory fix.

[tomtom72]

Hey, on an EFI car you don't step on the gas to cold start it. That's what the IAC is for, isn't it? The blades do not move, rather by-pass air is allowed in thru the IAC? You just turn the key over to "start" and when it fires you release the key and it idles on the fueling program labeled "cold start" in the PROM, no? Okay, I know that is an over simplification as the coolant temp and closed loop stuff comes into play...but basically just turn the key. If you don't step on the gas you would never know that the T/B contracted around the throttle blades, right?

The rest of the stuff about the HP gain from having the spacers is open to debate. If the T/B is cut off from coolant it would take awhile for it to warm up due to conductive heating. If the ambient temps were low enough, and the insulator blocks actually do what is advertised, it could interfere with the conductive heating of the T/B. In theory, if the spacers are true insulators you could wind up with steel throttle plates binding on an aluminum hole.

[carter200]

Paul and USAFPILOT,
Paul needs to take a chill pill and read my response about the billet throttle body plate. I, in jest, put that it was good for "up to", meaning from 0 to 50 hp. It was a joke!
Yes, USAFPILOT, I was funnin with you guys as NO throttle body plate makes any HP.

C'mon everyone don't take everything people say as the gospel. Humor is your friend in these tough times. Rick can back me up on this one, too :dancing

[carter200]

what plate are we talking about that can get you 50HP? Are you serious?

A 50 hot of NOS is the only plate that would do that. No, I was funnin with you all. :mrgreen:

[carter200]

The rest of the stuff about the HP gain from having the spacers is open to debate.

No where in any of the posts did anyone say that the insolating plates Rick has makes any HP. Please read the complete posts before reacting.........

[tomtom72]

You are right Carter!
:o I should have wrote that the magnitude of the effects upon the HP production are open to debate as a result of using the insulators. My apologies. :o

I think anything that keeps the intake system from becoming a heat sink should deliver cooler air to the cylinders, and cooler is always better, right?

[xlr8nflorida]

No where in any of the posts did anyone say that the insolating plates Rick has makes any HP. Please read the complete posts before reacting.........

There is a company that makes spacers for plenum, ih, tb etc that claims horesepower gains.

I can't remember name of company now maybe randy woods?

[Paul Workman]

There is a company that makes spacers for plenum, ih, tb etc that claims horesepower gains.

I can't remember name of company now maybe randy woods?

Long as were havin' fun, there is also a company claiming their "Tornado" will add up to (something like) 25 hp and gobs of improved mpg. Sheeeiiitt! You mean I coulda got the same results with a spacer and a "Tornado" that I'm getting with full porting and exhaust upgrades????

BTW...I wasn't intending to take anyone to task: I fully realize hp claims abound for all kinds of gadgetry. Some work, most don't (except under the most bisare special circumstances, circumstances that so often negate anything remotely resembling a scientific approach...)

:cheers:

P.

[xlr8nflorida]

I'm not talking about some crappy tornado.

The company I'm talking about has a good reputation of quality products.

Does it work to manufacturers horsepower claims, I doubt it but I guarantee it helps with heat soak. Many drag racers ice down their engine between runs to avoid heat soak.

[VetteMed]

To add to the confusion a little here, I have experienced throttle sticking in other cars with the TB coolant bypassed (TPI motors), but the interesting thing here is that a new throttle body corrected the problem - which leads me to believe that sloppy throttle plate shafts or bearings may predispose to sticking of the throttle. On a "new" motor, it's probably less sensitive to the minor changes in dimensions associated with thermal expansion/contraction, but throw some slop in tolerances into the mix, and maybe there's enough change in geometry to create a problem.

[rhipsher]

Hey, on an EFI car you don't step on the gas to cold start it. That's what the IAC is for, isn't it? The blades do not move, rather by-pass air is allowed in thru the IAC? You just turn the key over to "start" and when it fires you release the key and it idles on the fueling program labeled "cold start" in the PROM, no? Okay, I know that is an over simplification as the coolant temp and closed loop stuff comes into play...but basically just turn the key. If you don't step on the gas you would never know that the T/B contracted around the throttle blades, right?

The rest of the stuff about the HP gain from having the spacers is open to debate. If the T/B is cut off from coolant it would take awhile for it to warm up due to conductive heating. If the ambient temps were low enough, and the insulator blocks actually do what is advertised, it could interfere with the conductive heating of the T/B. In theory, if the spacers are true insulators you could wind up with steel throttle plates binding on an aluminum hole.

Exactly! Now I don't feel like I'm the only one this makes sense to. Sometimes these threads turn into so much over analyzing it's ridiculous. Just cracks me up.

Lets Recap:

1. High idle does not happen on startup in cold weather.

2. Whether its 30 seconds after startup or a half hour after startup, when engine is hot, it makes no difference.

3. High idle only happens after you push the gas peddle down and the throttle plates don't come back down and fully close and sometimes just a quick tap of the gas peddle will un-stick them and they will fully close and idle at normal rpm. Simply a mechanical binding problem.

4. Steel does not expand and contract like aluminum. Throttle plates are steel or some kind of alloy. The throttle body is aluminum.

5. Allowing coolant back into the throttle body 100% eliminated this totally. Case closed.

You guys can do whatever the heck you want to if it happens to you. I shouldn't of even bothered posting this. It seems half of the time to be implied that I'm wrong and there's some other reason things are happening or I just got lucky or something by some of the guys on here. It just couldn't be because my solutions are common sense. No! there has to be a more complicated reason. That just grows old after awhile.

My car runs just great because I know how to fix it. I don't have Heart of the beast or one FSM on the car. Nor have I ever needed them to fix it.

The only reason I post anything like this is to help somebody else out that might be having the same issue down the road. Not to brag that I fixed it or to feel smarter than everybody else. Just simply passing info along that's all.

Idios Amigos

[xlr8nflorida]

I was talking about something else in this thread:


Plenum Insulator Kit


Low profile (1/8" thick) phenolic insulator plates assist in plenum temperature reduction, while minimizing the chance of hood interference. Plates incorporate a bypass port for proper coolant system venting. Kit includes: plates, throttle body coolant bypass line, line plugs, and fasteners.

Throttle Body Insulator Plate

Thin (1/16") phenolic insulator plate is designed to assist in the reduction the throttle body
temperature while maintaining proper mounting
location and throttle cable slac

[xlr8nflorida]

Is there more informaton about the Plenum Insulator Kit (write up, discussion, pictures)? :cheers:


Perhaps later?


Running to store to get:

$4 Mobil 1 Extended 10W-30
$4 Mobil 1 High Mileage 10W-30
$4 Mobil 1 Regular 5W-30

Going get 2 Shopping carts full!

With my savings, I'm going get 2 Tornado's.

[sammy]

just go to randy woods site he has a plenum and t body phenolic spacer . i have this setup on my white car and at the drag strip i can now put my hand on the plenum right after a run compared to burning my hand before . how much it helps i am not totally sure ,,but it cant hurt . randy has results from a dyno on his site

[sammy]

rick thanx for sharing, knowing you as i do a standup guy , you would never share anything that wasnt totally true . also i dont think they make a tornado for our cars

[pantera1683]

Perhaps later?


Running to store to get:

$4 Mobil 1 Extended 10W-30
$4 Mobil 1 High Mileage 10W-30
$4 Mobil 1 Regular 5W-30

Going get 2 Shopping carts full!

With my savings, I'm going get 2 Tornado's.

Get the Euro 0W40, that's the good stuff

[carter200]

You are right Carter!

I think anything that keeps the intake system from becoming a heat sink should deliver cooler air to the cylinders, and cooler is always better, right?

Tom,
That has always been my thoughts. Cooler the better.......

PS: Paul I have a tornado on my 2500HD and you would not believe the added MPG........NOT!!! :mrgreen:

[carter200]

To add to the confusion a little here, throw some slop in tolerances into the mix, and maybe there's enough change in geometry to create a problem.

I like em' nice and tight, too :dancing

[xlr8nflorida]

Perhaps later?


Running to store to get:

$4 Mobil 1 Extended 10W-30
$4 Mobil 1 High Mileage 10W-30
$4 Mobil 1 Regular 5W-30

Going get 2 Shopping carts full!

With my savings, I'm going get 2 Tornado's.

I was joking about the Tornados.

Randy Woods is the one selling them - www.zr1products.com

[sammy]

oh darn i wanted to try on tooo.. to see if the swirl really worked