Was sick of my sticky stock throttle body which GM so thoughtfully made non-rebuildable. Got a Holley thinking it was the best made of the aftermarket models. I swapped it and a set of LS1 injectors, found my engine idled like crap, and immediately suspected the injectors were not spec'd correctly. 4 hours later with the old injectors back in place, engine still runs like crap.

Put the stock TB back on, eyeballed the TPS to see it was near the correct position, and fired it up. Ran without any problems at all, except the throttle shaft, which was still sticky. Growing sick of this mess, I put another wrap on the thottle return spring and fixed the problem (for now).

Earlier posts indicate people have experienced idle problems after installing a Holley TB. The workmanship of the piece seems excellent, but even the best workmanship can't make up for crappy engineering.

I would spend more time comparing the two to try to figure out what is wrong with Holley, but I am at the moment more interested in having a vehicle that actually runs properly.

Has anyone actually installed one of these and had it run correctly with a stock BIN? In the meanwhile, I'm going to try to clean it up enough to get Summit to take it back. Right now, it's a $300 paperweight as far as I'm concerned.

 

Mine works fine. The only complaint I had was that I had to grind down a bracket on the throttle linkage so my cruise control cable would attach properly.

 

Do you have a pre- or post-1989 plenum? I'm wondering if Holley got something wrong with the EGR routing. Mine is a 1987 part.

 

my car is an '87. It's been a while since I ordered it, but I'm about positive I would have ordered the early model unit.

 

My suggestion would be to have the original one rebuilt by Dave Koldos. It's cheaper and you are using a proven design. He does outstanding work. Can bore it out also, as he did to mine. Follow the link, LeadheadRed listed his email and at the bottom I put up a sample of his work ( My 89 L98 Throttle Body)

https://www.thirdgen.org/techbb2/sho...hreadid=293727

 

I have a holley 52mm with no problems, high quality piece. There is no way you can"eyeball" a TPS setting you either need a digital volt meter or a scan tool, guaranteed your TPS has changed- you could be way out of the ball park, that could cuase it to run like crap, or if you have not done the IAC set up correctly ( PCM procedure to set it ) the car will not run right - that is a promise - it's not the TB - from what you have said - you haven't set it up at all - more than just a bolt on and go type item- one if you haven't tuned the chip the LS1 injector constant is different 25lb HR vs a 22 lb hr stock, even if you had a chip for 24lb hr it would still run a little different.

Set it up properly and I bet you will cure all your problems.

I like my holley, car runs great with it. - set yours up and you'll like it too

 

[QUOTE]Originally posted by Kennerz
[B]I have a holley 52mm with no problems, high quality piece. There is no way you can"eyeball" a TPS setting you either need a digital volt meter or a scan tool, guaranteed your TPS has changed- you could be way out of the ball park, that could cuase it to run like crap, or if you have not done the IAC set up correctly ( PCM procedure to set it ) the car will not run right - that is a promise -

Oooops!!! yeah, good points!! Must be my late night tunnel vision as I only focused on the throttle sticking. Definitly need to set your TPS and idle speed.

Cant say much regarding the Holly TB as I never owned one but I was definitly happy with the results of my rebuild.

AHHHHhh, but when the rebuild was done, had to break out the scanner to dial in the TPS and IAC numbers.

Regards

 

Saying that I "eyeballed" the TPS after replacing the Holley with the old throttle body was to make the point that the old 48mm unit obviously runs much better even before bothering to set the TPS properly. I tried everything I knew with the Holley, short of reprogramming the PROM.

I went through the whole minimum air and TPS adjustment cycle with both the Holley and the stock throttle body. I am also still running stock injectors (22 lb/hr).

Would gladly check the IAC settings and possibly change the injector constant to install the LS1s again (would be my third time to have the intake apart this week), but it seems my Pocket Programmer has crapped out, as well. This just hasn't been my week.

 

I remember it took me a few times to get it right. when I was setting the base timing the idle speed would change, then I would have to do the minimum air adj. (idle screw) and the IAC routine, and check , and reset the TPS setting every time you move that Idle screw, you change the TPS voltage.

Of course the 48 works close - it's stock - stock stuff should work in the ballpark. Every manual out there lets you know that a bare TB ( new IAC, or R&R IAC, TPS) is not plug and play, the holley is sensitive to settings. Be patient, follow steps for adjustment to the rule - there are no short cuts for this - make sure you did the steps in the right order -
1.time it - get it to run -set base timing - if it didn't change for any reason - ignore this
2. I think next is IAC setting - jump the ADL port with a paper clip, wait 30sec~ 2min till IAC pintle fully extends and closes the port - disconnect IAC plug
3. set minimum air speed ( Idle ) with the screw on the side.
3A. plug IAC conn back in.

3B. Does it idle ok now? - if not - procedurally something may have been wrong
4. set TPS - if TPS is way out you may need to repeat step #2 , then #3 and then #4 again.

Pain but once it's right - don't touch it - it won't change

- did you use an new gasket on your IAC? the IAC can be a booger if you arent carefull with it - it can make your car run like crap.

I went through this a couple of times till I got it right and the IAC counts on a scan tool were in the correct range at idle.

just because your stock one works doesn't mean your holley is a POS-

I found if I didn't do this in order and follow the steps closely my car did not run right.

Best of luck