Recently I got tired of my sticky uneven throttle body. I was stuck in construction traffic and inching forward became almost impossible. I decided to repair mine. The throttle body shaft has no bearing. It is steel against aluminum. In time the round hole becomes an oval one. This makes the throttle plate operate erratically. It even sticks when in the closed position.

I made a setup in my machine shop to repair these. I accurately locate the shaft hole and boar it to fit an oilite bushing. I have done a dozen of these so far. In my car, the difference was incredible. I expected the operation off idle to be improved which it did but I also found the operation was smoother through the operating range.

I decided I could offer this as a service. In this, I will clean the body and install the new bushings. This operation requires special machining in order to keep things aligned properly. At this point, I am not plating anything. I am only cleaning the steel components. I may offer plated parts later but not at this time. I will need a core in exchange for one I send out or I can repair yours but there will be a delay in doing this. There are some that have 2 ports and some with only one. Some have a built in return spring and the other does not. You can see the differences in the ones pictured.

If you are interested in this service, My starting price is $125.00 plus shipping

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Sounds like a great deal!

Nice. Have you thought about doing this with Weber carbs too?

The late Mike Cooley also provided this service. He pressed Oilite bushings in and reamed to fit. He did a number of them, but it wasn't enough to keep him busy, so eventually he sold off the tooling. When people started asking him to do more of them, he tried with the wrong tooling--and it didn't work very well.

Glad to see someone is providing this service again!

--DD

Harry Bieker of Bicker engineering did Webbers but it took forever to get them back but his work was tops. He had lots of special jigs. Drilled bushings out and then pressed new ones in and fit new shafts.

Bob B

I am sure I could. Let's see where this goes first

Definitely interested. But I need plated parts, so I'll disassemble mine and include pre-plated hardware to reinstall.

Hi Mark

If interested in this, please include any plated parts so I can make sure all fits smoothly. Plating will be available in the not too distant future

Very interested in this service. I can send it to you when you're ready - just let me know. Thanks!

I'm interested as well, do you offer core service so my car is not down during the process?

Got a spare TB stripped down. Wire brushed all the steel parts. Ready for zinc plating. Polished the throttle plate for fun. And soda blasted the body. Once I get the steel back then it'll head your way. It actually feels like it's in pretty good shape, but I'll send it along anyway and wait for your assessment.

I can do that!

Hi Mark

That look really nice. I realized more people are going to expect a better finish that what I pictured. My camera does seem to make things look worse than they are. I have started to glass bead blast the parts. They are looking better. I am also replacing the nut with a silver colored zinc plated nut. I am also replacing the 2 washers with Stainless steel ones. These are also silver but will never corrode and are very smooth. I am looking into plating.

Let me know what needs to be done. I have a 75' throttle body with a built in return spring.

I also seem to remember someone offering to open up the throat with a larger throttle plate, does this offer any performance enhancement?

I am planning on making this available also

Mark or Anyone does modification this make an appreciable difference with a stock euro piston 2.0L with SS heat exchanges and Bursch exhaust.

thanks

I have no idea but I did do a calculation on this. The TB is 45mm. A 10% in area (2.0L to a 2.2L) it needs to be 47.5mm

Need to be vigilant with thorough cleaning when bead blasting anything that will introduce particles into a motor's internals. Glass beads will destroy a motor's internals.

May I suggest soda blasting as Mark has done? I've seen motors destroyed due to captured, then dislodged glass beads.

Of the almost three hundred throttle bodies I have machined only a few customers have asked to bore the throttle body casting larger than was necessary to clean up the grooves left from the throttle plate wearing down into the bore and the opinion in almost all cases was that the extra overbore did not contribute a great deal to performance, my goal in re-machining these throttle bodies is to provide a very smooth and long lived assembly that will give the driver a sense of driving a different car by having a stable idle and eliminating the sticky throttle.

Phil

I too was concerned about this. I also have soda blasting and it did an OK job. I am bead blasting the steel parts. The bodies I have blasted are followed up with a real cleaning with soap and water. I am sure they are clean

Pine-sol will do a real good job cleaning the bare AL casting.
But it strips the finish off of plated parts and discolors brass.


http://www.914world.com/bbs2/index.php?showtopic=109676

Maybe a shake session in an ultrasonic tank (HF sells an fairly inexpensive one) would dislodge any captured beads?

Good Idea. I have an expensive one. I will see if it fits

I remember seeing this awhile back. I had forgotten about it. Thanks for the reminder.

Walnut-shell blasting is popular for cleaning ports of coking found in modern DFI-equipped engines. Some BMW and MINI models, in particular, seem to need this periodically. The blasting is done without disassembling the motor, so presumably the walnut material is harmless if it gets into the combustion chamber.

At least worth thinking about.

--DD

Mark,
I'm in and sent you a message and picture of my current throttle body on Sunday, any idea on the ETA?

Thanks,
Dan

Bump for a great service. Installed my refurbished TB yesterday. Thanks again for offering this

I shadow, Shadowfax's sentiments..

I received mine last night and will install this weekend and report back.

Glad you got it OK.. Thanks for the feedback

I am running into a busy schedule so repairs may be on hold until my work schedules clears.

Installed the TB today set the TPS, Dwell and Idle.

Now I have to get used to not expecting the throttle initially sticking.

Thanks Mark

New bronze bushing
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My attempt to grease the original throttle shaft a while ago
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Top shot of the new throttle body
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I am glad you like it!

Is that like remembering exactly where there's a scratch in a song on vinyl LP album?

...

how about adding an overbore option like Ed Mazula used to do?

it makes a great midrange boost on a 2.0 type 4

apparently his biz is no longer - bigborethrottlebodies.com

Got mine back a little while ago and finally took pictures. This'll be going on my 1.7 Turbo engine when I have time for that. I thought the part I sent in was in great shape. I didn't even think it really needed rebuilding...but what I got back was even better.

Bottom line is that pretty much everyone needs this service.


Pictures- I sent my own parts for zinc plating, and the TPS is for my MicroSquirt setup.

Mark are you still offering this service? Sent you a PM but haven't heard back.

-Shawn

Do you still offer this service? Thank you.

Ditto?

Mark rebuilt my throttle body this summer.
Quick turnaround and very reasonable price .

After installing Mark's rebuild it eliminated my annoying high idle and now it's perfect @ about 900-RPM

Tom Highly recommended & good guy.

Sorry Mark
Those are the original photo's & I don't have a finished photo, but it was excellent workmanship
Tom

Well take a finished photo Tom! We’ll wait