i just joined this message board today because i have a problem that is driving me crazy. i have a 95 z28 with all the standard bolt ons, nothing crazy. i got a 58 mm holley throttle body a few months ago and heres the problem. this is the third throttle body from summit because i thought i might be a defect but is obvisiouly not. with the car off, the linkage moves open and closed prefectly smooth. when the car is running, it sticks all the time. i have a scanmaster, and when i let off the gas, the throttle position percent (tpp) won't come back down to zero. it sticks at anywhere from 1 to 9 percent which makes it a real pain to drive. i set the tps to .48 volts and tried it everywhere else and still have the same problem. this thing is installed perfect - torqued and port matched. the coolant is bypassed, and can't be that because as soon as the car shuts off, the linkage moves perfect again even when hot. it has a new iac also. i moved the stop screw all the way in and out and adjusted the tps back to .48 volts each time and i always get the same problem. when i get under the hood with the car running, it is tough for the linkage to come off of the fully closed position and wont return to fully closed unless i give a nudge back to closed. one thing that i noticed though is that i know that the iac should be between 20 and 40 at idle. if i put the stock throttle body back on, everything is perfect. but the holley, the iac will drop to zero, and i figure that is because i am so far out on the stop screw to get past the "sticky area." this sticky area is only between 0 and about 9 percent when the car is running. please - does anybody have any ideas what the heck could be causing this??? vaccuum problem maybe?? all readings are perfect and no signs of a leak when stock unit is put back on. the egr is not stuck open either and this has nothing to do with the cable, i've heard that plent of times already. holley has no idea what this could be. please help!!!

 

Its a common problem with the Holleys. Mine does it too. I did get it better by removing the blades and filing them so they dont touch the body. Also added a small return spring. Occasionally spray oil on the shaft. Thats about all I can tell you. Oh,and welome to the board.

 

I didn't have your problem, however, my Holley opened greater than 90 degrees and I had to build a WOT mechanical end-stop. Also, it was generating TPS voltage high DTC and causing shift issues.

WD

 

Sounds like the blades are sticking in the closed position. As noted in the first response, they may need to be sanded down a bit. My Holley was just the opposite... a huge gap between the blades and the bores.

You can also increase the tension in the return spring, by moving the end of the spring to another hole on the side of the throttle body. But if the blades are wedging into the bores, they need to be resized.

 

Call Holley they have a link about that.

 

Had a sticky throttle that was due to crappy design.

The solution: Arizona Speed & Marine.

 

Reason why I chose my Edelbrock (Older version, no BBK on Plate) I have a monoblade AS&M too I'm going to be using on my spare engine. IMO they all kind of have their own flaws. It usually takes a little bit of adjusting to get anything aftermarket to perform right.

 

/\ /\ Very true statement for most aftermarket performance parts! I had to work-over my Holley to get it right. Now it works great!

Also, my MSD Opti and about every other aftermarket part I've got on my engine.

WD

 

I have seen a lot of people on here have problems with Holley tb's. I personally have a professional products 58mm and I have not had 1 issue with it. I did the research before I bought it and read all of the negative stuff that was said about their products but no one could ever say anything bad about their throttle bodies. Yet all other tb's are apparently not great either. I decided to see what kind of product they could produce for myself and I must say that I am very impressed. BTW when i first recieved my tb i took it to my machine shop at my job and they couldnt find anything wrong with it either. I have had it on since November 07.

 

Mine sticks a little too. I just hit the gas real quick with my foot while I'm driving just prior to a stop just a tad and realy quickly without getting the car to actually jolt forward to get the blades to slam shut. That does it for me.

Once I get to it I'll install an extra spring to help it out while I'm driving so I don't have to do this. As stated above with the slight modifications to the part I'm sure you'l get it working correctly.

 

I have had mine for 7 years no prob at all just you have to modify the tps so the car will idle fine basically you have to drill a hole on the tps screw and start adjusting.