ctandc

When I first got my IROC, it needed a GOOD bit of work. One of the things that happened when I first started tuning it really pissed me off...I broke the bottom TPS screw off. I was using a 1/4" flex extension and ratchet...it snapped like I was using a breaker bar.

I ended up adjusting everything to spec, and using just the top TPS screw to hold the adjustment. There was a good bit of the bottom screw left in the TB, so it held up fine.

Now as it recently got cold, and with the addition of headers, I needed to tweak it a bit. Set the timing, set the idle in gear and minimum air setting, went to adjust the TPS and the top screw snapped. It broke JUST the head off the alum piece of scrap, and I wasn't using any kind of effort.

After searching fastener supply, hardware and other stores, I then searched these boards.

The factory TPS screw is a 30mm long bolt with a 4.5mm diameter and .75mm thread pitch. GOOD LUCK finding one. For those who want the factory replacements...the ONLY way to get the TPS screws from GM, is to order up pt # 17110848

This includes the TPS screws, as well as the screws for the top plate on the TB.

GM list is $25
Shipped from www.gmpartsdirect.com is right under $20.

Yup, you got NEW screws, but they are the same lightweight pieces of crap you had to replace.

Go to a tool store and spend $20 or so for a good SAE and or metric tap and die set. ( You'll really want one if you ever build a motor anyway ) and if you don't have it get some good drill bits.

IF you DON'T have to drill the holes out for the TPS screws ( you were able to get those screws out ) it's simple. Take a 10/32 tap, and MAKING SURE you start it straight / level in the hole(s), slowly work it in ( not hard, it is alum ) the existing hole.

Back it out slowly, blow the shavings from the hole, or use a trick I learned and put some grease on the tap ( works on drill bits to ) and it will keep most of the metal on the tap or bit.

Now get some 10/32 Stainless machine screws with a Phillips head. I used a length of 1 1/4" and it worked fine. Also buy a few washers for each screw. Now just replace the screws and mount the TPS.

If you're drilling broken screws out, use a #21 drill bit for the 10/32 screws.

You'll never had to worry about breaking a TPS screw again. You'll strip the hole LONG before you'll break the screw



Chris
85 IROC

Jekyll & Hyde

I went and purchased a new TPS sensor from autozone. The brand was wells and came with two new screws and the satisfaction of a new sensor on the car.

Jim85IROC

iTrader: (2)

I bought the proper size screws either at Aubichon Hardware or at Advance Auto... I forget which place. I also have no doubt that Fastenal or a similar store can get them. They aren't that hard to find, you just need to look in the right places.

Forget about getting them with a torx head though. I broke off a few of the bolts that hold the IAC housing to the throttle body (same thread pitch I believe) and replaced them all with more bolts like what I mentioned above.

I will say, however, that the Holley throttlebody comes with a different, much easier to find thread size for the TPS bolts, which is a good thing because the dolts include bolts that are TOO SHORT TO WORK with the stock TPS. Pure genius. They can mill a throttle body from a solid chunk of aluminum, but can't include the right length bolts.

RRustenholtz

I too just got done fighting with the same issue. I adjusted the TPS on one day.... then a few days later removed the whole throttle body to clean the carbon out of it. I broke both tps bolts with no effort, and one of the bolt on the bottom plate as well. The threads stuck in the plate so it is still secure, just sucks I didnt get to clean that out. 32 Year old 1985 Iroc Z28. Im sure im going to break even more stuff when i pull the motor.

Tuned Performance

iTrader: (92)

15 year later ... lol

RRustenholtz

yeah I just bought my second camaro. First one didn't last long. I'm actually surprised people are alive here lol. All these threads are older than at least 2 of my kids! :P 32 YEAR OLD SCREWS SUCK.

RRustenholtz

Yup.