Throttle body question ????

[vetfever]

I installed one of those good looking throttle body covers on my 96 LT1 last night. For some reason, I could not get all of the screws to "seat" fully. Two of them didn't screw in all the way. I didn't want to risk stripping the head, and it really feels very secure with the others all the way in.

Is there any harm in leaving it like it is? What is the purpose of the cover anyway? Any technical help appreciated!! Thanks.

 

[sothpaw]

I think the cover is just aesthetic.
But, you don't want a loose screw
flying around in the engine compartment!!

I would use loctite (high temp) to secure
the screws or put the
old plate back on.

 

[Ken]

The plate is called a "Clean Air Cover" and if it's not sealed properly it will cause driveability issues. Other that that, you're right - it has no real function.

_ken

 

[vetfever]

Thanks guys. I spoke to a mechanic about it over the weekend. He said that there is actually a vacuum there and if not sealed properly, that the intake could pull in dust, etc. I have it sealed pretty well, but he will run a tap down into it to clean out the threads and get it looking right. The look of it bothers me as much as the mechanical concern! Thanks again.

 

[topless82vette]

ken

about these driveability issues just how severe would they be ? I have a 84 trans am that I did a tpi conversion on its a speed density setup .... that surges really bad under light acceleration but has all the power in the world under full acceleration I know this plate you are talking about mine only has like two bolts in it with no gasket so Im just curious maybe this is the culprit as to why it never runs right also car is using a painless harness new injectors sensors etc., and just how bad of a vacuum leak can this loose cover cause, also what driveability issues would no speed sensor cause and the nuetral start switch not being wired into to ecm cause

 

[Vettelt193]

it all depends on how bad the leak is, but if it is getting a good amount of air through there it would definitely act they way you describe... under full throttle the car is trying to get as much air as possible anyway, so it wouldn't matter then.... Does the car idle fast too? it would cause a high idle condition (but the computer may compensate for it after awhile) If you fix it, you may find the car won't idle, or has a hard time doing so... if this is the case, disconnect the battery for a few minutes to re-set the computer.

 

[Ken]

Bob just about covered it Jeff.

_ken

 

[topless82vette]

vettelt

vette its been so long since Ive driven my baby but I remembered it always had a small stumble when idling, starting it always fired first turn of the key, Im sure electrically speaking its not suffering as it to has a camaro serpetine system with the high out put alternator, Ive see so many of these conversion that ran so well it often left me dissapointed that mine ran so (it will be masked so why type it LOL ) to the point that I was ready to rip the system off and stick the old feedback rochester back on it, this weekend I will pull it from its resting place behind the house LOL and tell you more specifics on what it is doing

 

[topless82vette]

ken

in another post you did about sagging bumper covers I had a body shop send my cover out to a company that would take your cover and heat it and restore it to its original shape I had it done on my trans am after it had a small bump in the rear end the body shop excalibur sent it out and it came back real nice but Im not even sure there still around and I didnt get there name from excaliber

 

[Ken]

Jeff, I'm sure heating it would allow it to regain its shape, but would it hold it? The problem most likely will reoccur because that area of the fascia is pretty weak and susceptible to sagging. It needs some extra support in the center of it.

_ken

 

[topless82vette]

ken

where do I find info on corvette shows/meets/cruises I want to start going to them when the vette is finished, I really only interested in southern california events since I just don't have the time to travel

 

[Ken]

First off, I'm sure that you keep an eye on the Calendar we have here, right?

Secondly, I would suggest finding a club that is close to you. There are many here in SoCal; if I knew where you are I could possibly recommend one for you, seeing as how I mail a copy of our (Southwest Corvettes) newsletter to about thirty to thirty-five clubs each month. They range along the coast from the Santa Barbara area in the north to San Diego on the south, and from Bakersfield to Riverside on the inland side of things.

_ken

 

[topless82vette]

ken I live near riverside about a hour from where you are

throttle body ok I untarped the t/a today it started right up after a year of sitting but has a real rough idle that cover on the throttle body has 3 screws in it but doesnt have a gasket, also what effect would no vss signal have on tpi and when I installed the painless harness it said connect a terminal to brake switch thats nomally close/open and one to the shifter nuetral start switch thats normally closed/open oh and also my cat convert. is open, Im not to great at wirring issues so what do these switch signals do for the computer car holds approx. 700rpm idle whether its in gear or neutral, Im a 100% sure its not the engine itself as it was replaced about 20,000 miles ago and ran great prior to tpi installation and all vacuum lines are new and routed correctly & fuel pressure was at like 40-50psi but I cant remember exactly what it was, the distributor was also completly rebuilt alll new sensors, ecm, prom was supposedly programmed for my gearing, trans, and motor unless they were just passing bull onto me, fuel pump is a unit from tpis can feed up to like 400hp but it was so noisy I went to a in tank gm pump (the tpis ones for sale LOL ) Ive tried vacuum leak detection but none were found around plenum, runners, injectors.

well any help would be appreciated

 

[Ken]

Events in California? Go to California Car Clubs.

Wiring issues? Who ya gonna call? VIGMAN!!

The throttle body issue: If all that stuff came from TPiS then they weren't BS'n you. If it's been sitting for a year or so, the Idle Air Control (IAC) could be dirty, but I doubt it. The rough idle is more likely due to the missing gasket on the throttle body "clean air cover" (the plate on top of the TB ).

Maybe someone else can offer up a few suggestions.

_ken

 

[topless82vette]

the trans am has defeated me, after many hours off messing with the tpi system, Ive come to the conclusion it quite possibly could be my camshaft, I have no idea what make it is or the specs on it, but I do know at idle (timing right on, no vacuum leaks) I'm only pulling like 13-15 inches of vacuum, I readjusted the valve to no avail, still no improvement, keep in mind this is a speed density tpi system, its still running rich, and also surging very bad while accelerating, I did change plugs, new wires fuel filter the whole nine yards, with no improvement seen, can this low engine vacuum be the ultimate heart of my problems since the map sensor is seeing such a weak signal ? if so I have a painless harness for use with a mass air flow system, would I be better off switching to mass air flow since I do have this low engine vacuum problem, you probably have questions about whats in the motor so I will answer them the best I can, first off its a 78-84 305 thats been bored .30 over, flat top pistons, I am using the stock heads that came with my trans am (no porting or anything like that has been done to them, they were however milled just enough to to rid them of imperfections, machine shop told me they had no cracks or any signs of excessive warpage) I'm using new bosch 19#lbs injectors, compresion is 170-175 per hole, however as I said before the guy that built the shortblock didn't know what the cam was.

so whats your opinion switch to mass air flow, Im not really to thrilled about changing the cam and will mass air flow be able to not depend on any vacuum signal, I really dont know much about how the two systems differ, but this tpi system used to be a mass air flow unit, still has the 9th injector so putting a new harness in it shouldn't be hard I HOPE

 

[Ken]

.,.. so whats your opinion switch to mass air flow?

:L Don't get me started there. I don't know if you are familiar with my engine project, but I am currently in the process of switching to speed density FROM mass air flow. Of course, mine is a little more radical than what you've done, but our headaches are the same I'll bet.


In other words, I don't have an answer for you at this time.

_ken

 

[topless82vette]

sad huh ken, Ive got speed density, and going back, hope you don't end up going back its pretty frustrating, hey if you ever need a good tpis pump let me know mines has maybe 2 hours on it and best of all its free

 

[Ken]

... best of all its free

Sometimes I can't even give things away for some reason. :L

Thanks for the offer, but I don't know if that'll be enough for mine: I estimating approximately 535 horsepower at the flywheel.

_ken

 

[topless82vette]

ken

if your interested its a tpis pump part # 300-177 ... just was reading and wonder if it is just way to much fuel for my system

 

[topless82vette]

ken

535 hp. astounding, I guess I'm still in the dark ages I have yet to get close to 250 hp. LOL .... remember if you see a nice blue 82 convertible vette namely mine, do remember it's not in your league and have pity for the driver LOL

200hp cfi speed machine