Hey guys so I just want some insight before proceeding with buying a nick Williams throttle body for my fast 92 intake. I have read and read and read every available thread in regards to cheaper throttle bodies and drive ability issues but just want clarification to justify spending $400. So with that being said when I bought my fast 92 I purchased a speed engineering 92 throttle body that came with a new iac and no tps sensor. I swapped on my tps sensor from my stock throttle body. Had a buddy come over to do a base tune just to get it to my dyno tuner an hour and a half away. Immediately we noticed the tps voltage was way way off, so we tried slotting the tps to try and get the right voltage and ended up having the tabs almost gone by the time we were done just to get the right voltage....so we got it running, wasn’t prefect but was at least driveable to the tuner. So I go to the tuner and he starts doing his thing, now this throttle body has no hole in the blade so he had to crack the blade open with the set screw. Well he gets it driving decent but because the blade is now cracked open I noticed at low speed the car was literally driving itself and when coming to a stop it would surge and stall out. Doesn’t do it all the time but most times at a red light or coming to a full stop I have to be ready to two foot it. Now the other thing is that I couldn’t test while at the tuner was cold start....well every time I cold start it now I HAVE to be on the gas just to keep it running or it will just shut right off. As well as when the car is warmed up if I gently roll into the throttle and let off the car will stall out no matter what it never catches itself. So after doing some research I found two things, 1. The iac holes are TINY compared to other name brand throttle bodies and 2. A lot of people say that having a hole in the throttle body helps a bit with idle but others say to rely on tuning but unfortunately tuning alone was not working. So I dremeled out both iac holes and started drilling a hole in the blade starting with 1/8th and starting the car to test cold start, eventually I ended up with a 3/16ths blade hole and had the blade all the way closed and was able to cold start it and have it somewhat start by itself, I had to coax it with the gas very minimally before it caught itself and idled fine but I noticed that it was running verrrrry rich so I’m assuming now it needs to be retuned again for the changes. The other issue I’m continuing to have even after all this experimenting is the stalling when I gently roll into throttle Still does it after dremeling the iac holes and doing the blade hole.
SOO, at this point I’m leaning towards just dropping the coin on a Nick Williams throttle body but wanted to know for those who have installed one was it literally just bolt on tune and go or have some of you had to modify them as well to work? I’m just sick of messing with this cheap *** throttle body I just want my driviablity back and not have to worry about cold start and stalling anymore

 

Yous should learn how to tune it yourself.

with the IAC tuning, you have to move the IAC/EA table over to the right a cell or two, and add a corresponding zero or two in front. That's really all you can do. The ECM really relies on that IAC/EA table heavily for idle calculations, and you can't mess with it too much. Start changing the numbers in it and you see weird stuff happen with the IAC counts over multiple drive cycles.

 

unfortunately I don’t understand much with tuning I can work a wrench but the computer stuff I don’t feel comfortable messing with.

 

Anyone else have any insight?

 

Maybe give speed engineers a call and explain the your situation with the iac hole being so small and no hole in the throttle blade. Maybe they did all of that for a reason. Maybe the can help with a few tuning tips since it’s there Tb

 

Common problem. Get yourself a nick William's 92 not the fast. The fast has idle issues because the hole is too small (maybe they resolved that by now but it has been a big problem in the past) you cant compensate and tune for a chinesium garbage throttlebody I dont care what anyone says. Edelbrock and holley also make great throttle bodies but the NW is proven and at wsystore it's only $389.

Also, I agree. Learn to tune it seems scary but if you can build it and understand how the engine operates then your smart enough to not blow it up and teach yourself how to make it run. It will need to be retuned anyways.

 

Need a 105 tb

 

I did that and they literally offered no help besides tell me it needed tuning...didn’t even bother to mention if there was anything in the tune specifically that should be reworked

 

What throttle body do you run?

 

Honestly, i think with some of the really cheap throttle bodies, the part of IAC passage where the IAC pintle seats is machined for crap.

A lot of the lower IAC count cells in the IAC/EA table are defined by the shape of the IAC pintle and the seat.

If you're only having issues at high IAC counts, it's likely the overall size of the IAC passage. Low IAC counts, geg a different tuner, or melt the throttle body into a lamp. Or both.

 

Just bite the bullet and get a Nick Williams TB

 

Sadly, a data log would show what’s going on.

It usually takes a few sessions of tuning to iron out the cold start issues. Since you modified your throttle body, the tune will need to be touched up again.

 

Yeah. I would get a better tuner, as well.

 

***UPDATE***

ended up biting the bullet and scored a used nick williams 92mm throttle body from a guy who upgraded to a fast 102, bolted it on last night and was a night and day difference, but I am noticing a couple of the same things. On cold start I did have to give it a little gas to get it going but literally was 2 seconds and the car was running and idling on its own no problem. Mind you I did nothing to the throttle body I literally unboxed it and threw it on! Second when fully warmed if I give it light throttle up to say 2500rpm the car still has a hard time catching itself, it did a lot better with it but eventually one of the times I did it the car stalled out so I’m assuming that all it needs is a little more tuning and I should be golden, overall I’m pretty happy with it and wished I never wasted my time with that cheap *** throttle body!