Fourthgenfreak

I just tried to install a brand new Holley 58MM throttle body on my 95 Z28.When I would crank the car it was fine,but when I pressed the throttle it would hang up around 3000RPM.Has anyone ever had this problem?Is there anything to do without sending back?

2000GTP

I would check to make sure there are no kinks in the throttle cable, there are no obstructions in the way preventing it from properly opening and closing, and maybe try lubricating the spring on the throttle body.

Fourthgenfreak

I oiled the spring and no help.Also it only does it when the motor is running, it like the spring is not strong enough to shut the blades when its pulling air through it.

Buttercup

More than likely the spring is the problem and it has inadequate tension. I believe this is very common with the Holley TB's. On my BBK I simply wound the spring a bit tighter to fix the problem. I know some people install a helper spring between the cam and cable bracket.

Fourthgenfreak

Also I removed the EGR valve and installed block off plates but did not have anything to stop up the small fitting on the driver side of the intake.Could that have that much effect on a throttle body closing?

Buttercup

By the "small fitting on the driver side of the intake" do you mean you left the vacuum port completely open???

If that's the case it would have nothing to do with throttlebody closing but would definitely cause engine problems as it would be a vacuum leak. Plug it, plug it now.

Fourthgenfreak

No doubt! Its plugged now,I just could not find a rubber sleeve at the time.I may try to take the throttle body apart and wind it up another turn ,if not I guess its back to Holley!!

89TramsAmGTA

Had that problem on my L98. Turned out that the arm on the TPS switch was rubbing on the side of the Holley throttle body. All I had to do was take off the TPS switch and grind down on the arm some for clearance. Check to see if that is your problem.

12SCNDZ

Adjust your cruise control cable. It's probably causing the betterflies to hang open.

Frank
CPT

LT1 POWR

I had this problem with my NOS Holley 58mm TB. When it was off, it would return to 0% throttle, but while running it would only close to about 2% throttle. I tried everything you can think of, then I got smart and thought it must be vacuum related. So I drilled a hole through the IAC opening so that some idle air would pass through without having to go through the IAC motor. I haven't reinstalled it yet due to polishing, but I believe this will solve it. Here is a link to exactly what I did.

http://web.camaross.com/forums/showt...ghlight=holley
In this link, there is another link with pictures of how to fix this problem.

Injuneer

There are holes in the side of the body that allow you to tighten the spring by moving it to another hole.

Also, take the cable off and rotate the blades by hand. There should not be any binding. If there is, the blades may be rubbing on the bores of the body. If there is binding of the blades in the bores, make sure the blades are properly centered in the bores. Then check to see if the blade diameter is too large to allow the blades to move smoothly all the way closed.

91RSLT1

No need to adjust the spring. I was having the exact same problem, I used graphite lubricant to lubricate where the shaft goes through the TB housing and around the blades. I did this ~2yrs ago and zero problems since. Before i would have to blip the throttle to get them to shut. Also make sure the TPS voltage is correct.

Dennis93TA

X2! Same thing happened to me.

Heatmaker

Had the same problem with my Holley... tried everything but finally after months of frustraition, I finally found a solution to fixing the damn thing......
I sold it.

350 HRSS

I read about the issues people were having w/ the Holley, so I bought a BBK instead. Maybe it's not too late to exchange it?

Good luck w/ your issue.