88 Iron Duke fuel pressure regulator screw (Page 1/1)
Worcen DEC 19, 10:20 AM
So I messed up big time...I was working on my 88 Iron Duke, putting a new fuel pressure regulator on, and one of the 4 torx screws broke. The head completely sheared off... Picture from Google of the screw I'm talking about for reference.


Really don't want to try and source a new throttle body. Does anyone have any similar experiences or any tips on how to get a small screw extracted from the tbi without completing messing it up? I tried super glue and I'm waiting on it to dry. I'll try that when I get home from work tonight, I'm doubtful of its success though...

Also, does anyone know what size the screws are? I tried a 6/32 x 3/8 screw but the threads seemed too course. There's an 85 at a junkyard near me but I know the tbi on those are different from the 88s. Maybe there's a similar screw in there somewhere?

Thank you for any help
Vintage-Nut DEC 19, 11:57 AM
Remove the TBI from the Engine
Obtain a Professional Screw Extractor Kit {Counterclockwise Drill Bits and Extractors}
Counterpunch the Screws in THE CENTER
Start with the smallest drill bit, use the second drill bit, up the bit size to remove metal WITHOUT hitting the TBI threads
If you're luckily, the screw will back out, if not, use the extractor

If the TBI threads are damaged, use Helical Inserts {another kit}

------------------
Original Owner of a Silver '88 GT
Under 'Production Refurbishment' @ 136k Miles

Worcen DEC 19, 01:04 PM

quote
Originally posted by Vintage-Nut:

Remove the TBI from the Engine
Obtain a Professional Screw Extractor Kit {Counterclockwise Drill Bits and Extractors}
Counterpunch the Screws in THE CENTER
Start with the smallest drill bit, use the second drill bit, up the bit size to remove metal WITHOUT hitting the TBI threads
If you're luckily, the screw will back out, if not, use the extractor

If the TBI threads are damaged, use Helical Inserts {another kit}




Thanks! I have some extractors coming in Saturday. Gonna try my luck at it then and will report back. Hopefully I won't damage the threads but I'm definitely going to look into the Helical inserts in case I mess it up. That'd be my luck...haha.
Vintage-Nut DEC 19, 02:28 PM
Counterclockwise Drill Bits are the KEY, many times I have found that the screw will back out IF you remove enough 'meat' from the screw....

Good luck
cartercarbaficionado DEC 19, 06:24 PM

quote
Originally posted by Worcen:

So I messed up big time...I was working on my 88 Iron Duke, putting a new fuel pressure regulator on, and one of the 4 torx screws broke. The head completely sheared off... Picture from Google of the screw I'm talking about for reference.


Really don't want to try and source a new throttle body. Does anyone have any similar experiences or any tips on how to get a small screw extracted from the tbi without completing messing it up? I tried super glue and I'm waiting on it to dry. I'll try that when I get home from work tonight, I'm doubtful of its success though...

Also, does anyone know what size the screws are? I tried a 6/32 x 3/8 screw but the threads seemed too course. There's an 85 at a junkyard near me but I know the tbi on those are different from the 88s. Maybe there's a similar screw in there somewhere?

Thank you for any help


a ace hardware will carry a similar torx screw it will look different (rounded vs squared edge) but at least it should be torx also this is NOT imperial so its probably gonna be a like a m4? take another one out and take it to an ace hardware and they will have a higher grade torx screw plus the size finder and uh word of warning DO NOT BUY STAINLESS. it tends to cold weld itself into whatever you bolt it into and it looks like your access is pretty good but that might be the fact im not looking at it... can you fit vice grips in there? if not then be careful and hammer a slightly bigger torx bit into the remains of the bolt and apply alot of pressure once it is in there a bit and slowly turn
edit: im a dumbass and didnt read. yeah your gonna have to drill it... if you take the tbi off and strip it down then you can get some heat in it and take it somewhere to use a drill press to have a higher chance of drilling straight in and not messing it up, the hammering a torx in it would still work if you got a pilot hole and has a lesser chance of being unrecoverable if you break that off too. worst come to worst then drill it oversized like you plan and dont use a helicoil use a NUTSERT style insert since they tend to seal better from leaks

[This message has been edited by cartercarbaficionado (edited 12-19-2025).]

Dennis LaGrua DEC 19, 07:05 PM
I don't know Duke engines all that well but that broken screw stub shown in the picture looks large enough to grab onto it and turn it out with the smallest ViceGrip pliers. Am I seeing this correctly?

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Vintage-Nut DEC 19, 08:33 PM

quote
The head completely sheared off...Picture from Google of the screw I'm talking about for reference

[This message has been edited by Vintage-Nut (edited 12-19-2025).]

82-T/A [At Work] DEC 19, 08:56 PM

quote
Originally posted by Worcen:

So I messed up big time...I was working on my 88 Iron Duke, putting a new fuel pressure regulator on, and one of the 4 torx screws broke. The head completely sheared off... Picture from Google of the screw I'm talking about for reference.


Really don't want to try and source a new throttle body. Does anyone have any similar experiences or any tips on how to get a small screw extracted from the tbi without completing messing it up? I tried super glue and I'm waiting on it to dry. I'll try that when I get home from work tonight, I'm doubtful of its success though...

Also, does anyone know what size the screws are? I tried a 6/32 x 3/8 screw but the threads seemed too course. There's an 85 at a junkyard near me but I know the tbi on those are different from the 88s. Maybe there's a similar screw in there somewhere?

Thank you for any help




If you can make it to the yard, last time I remember the screws are rounded, but the screws in the 84-86 TBI are the same thread as the one for your 87-88 TBI.
Worcen DEC 19, 10:43 PM
Well fellas, it wasn't pretty, but I got the screw out. I mangled the hole pretty bad but I checked and the screw still threads in there, so I'm going to call that good! Haha



Also, At Work, thanks for letting me know! I ordered a few bolts online for dirt cheap i think might work, but I'm definitely going to go check that 86 out tomorrow at pull a part. I've been meaning to get up there for some interior bits anyway (if it's gray...car is gold so I'll bet it's Brown) I hope to get that black bezel piece by the cigar lighter. Mines missing. I'm definitely grabbing all the screws I can out of that tbi though!

Thanks again guys! You're all always very helpful
82-T/A [At Work] DEC 20, 09:04 AM

quote
Originally posted by Worcen:

Well fellas, it wasn't pretty, but I got the screw out. I mangled the hole pretty bad but I checked and the screw still threads in there, so I'm going to call that good! Haha

Also, At Work, thanks for letting me know! I ordered a few bolts online for dirt cheap i think might work, but I'm definitely going to go check that 86 out tomorrow at pull a part. I've been meaning to get up there for some interior bits anyway (if it's gray...car is gold so I'll bet it's Brown) I hope to get that black bezel piece by the cigar lighter. Mines missing. I'm definitely grabbing all the screws I can out of that tbi though!

Thanks again guys! You're all always very helpful




Definitely use some anti-seize when you put everything back.

And when you check out that 86... make sure you get a lot of the interior screws as well. Those hex-head screws in the interior were not common. GM used them in only a handfull of course, a GMC, a couple of Buicks and Oldsmobiles, Pontiacs, and pretty much that's it... and only for about 5 years. You can't buy new ones, but people lose these and they get messed up when they sit in bucks of random screws.