Author Topic: Throttle body bushing - David Koldos (Read 12860 times)

Stingraynut · « **on:** April 02, 2005, 12:40:22 PM »

The bore for the throttle blade shaft in my 88 is worn and the pressure of inrushing air when the engine is running, even at idle, makes the throttle stiff and sticky.

It's a fairly well known problem of the metal shaft wearing an oval bore in the aluminium TB because there's no bushes.

I spray grease into the shaft bore every 12 weeks which makes it smooth for a while.

Yesterday I contacted David Koldos in the US from a link on the Corvette Forum - he fits sealed bearings to the shaft,

His reply was quick and he's quoted US$145 for the work and $20 for shipping - very reasonable prices I think.

He seems to have a good name on the forum, but I'm just checking here to see if anyone has used him or knows anything ?

thanks

Stingraynut

Thunder Kiss · « **Reply #1 on:** April 02, 2005, 01:48:05 PM »

Never heard of him, but then I don't really spend too much time on any overseas forums.

I have a similar problem to yourself (maybe not as bad though) so I would also be interested to find out a little more. Would it be easier/better to purchase a used trottle body in the USA and have it shipped directly to him for rebuilding? Less down time that way, although I guess it would depend on what a used throttle body sells for.

The other question, what's a new throttle body worth?

Stingraynut · « **Reply #2 on:** April 02, 2005, 02:11:51 PM »

Hi Thunder Kiss, that's a brilliant action pic you have there.

David is going to send me a rebuilt TB and then I post mine to him, no core charge, he says "No core fee, I used to charge one but the logistics of returning it just wasn't worth the trouble. It seems that if people go to the trouble of searching me out, they're of the personality not to screw me out of a core. Also, I've been doing business with the cvette forum people for years now, great people to do business with.

To be 100% sure on application, it would be wise to get a couple of photos from the throttle linkage and opposite side of the throttle body. The early vettes used a couple different styles as far as vacuum fittings on the side opposite the throttle linkage."

As my 88 is my daily driver I have to minimise down time - I had been looking for a TB to buy or borrow for about 18 months - now I don't have to bother.

At first I thought the sticking throttle was my cable, so I replaced it - that's when I found out that the suction from the motor causes the shaft to bind in the oval holes it has worn.

I'm reallly looking forward to a smooth throttle!!! Sealed bearings will be better than original.

Like you, I try to source parts from Aus, this forum is great for that but it's not always possible. The Corvette Forum is very useful for info, providing you realise that some people post first and think later - I look for a concensus of opinion and weight replies from the known good guys.

Work done on my vette so far - http://www.users.bigpond.com/mphealey/Corvette/Maintenance.htm

S'nut

Thunder Kiss · « **Reply #3 on:** April 02, 2005, 08:06:26 PM »

I checked out your website, Stingraynut and all I can say is, "What a sweet ride."

With regards to your computer turning the fan on at 116 degrees, I was under the impression this only happened as a fail safe if the fan switch in your engine block dies. A standard fan switch should turn the fan on at around 109 degrees and you can buy lower temp fan switches which come on earlier.

86er · « **Reply #4 on:** April 04, 2005, 02:05:23 PM »

Hi Guys,
Have you thought about an aftermarket Throttle Body.
New in the States they are $299.00 US

Stingraynut · « **Reply #5 on:** April 04, 2005, 06:59:45 PM »

Yes I did think about it - but at today's rate that's Aus$388, and then there's the shipping - the major places like Ecklers seem to charge heaps for that - say $45 - we're up to Aus$433

Then it arrives in the country and you get charged GST and Duty, the GST is more than 10%...... you can guess how I know, I got hit twice last year - thought I was saving on the shipping by making big orders. A big mistake

Say Aus$140 for duty and GST- total cost could be around Aus$573

Luckily my third order last year - a complete weatherstrip kit including window rubber in/out, and steering wheel, was marked with a low value, so no duty to pay, but the major places put the true value invoice on the package.

My choice is US145+$20 shipping (Aus$214) for a TB with bearings - better than original, sounds very good to me!!!!

David has asked for pics of my TB to make sure he sends the right one, and requested a further close up of the RH Side - he seems to be very careful and precise, which is v good.

BTW - There may be about 5 different Tb's for the C4 - 85-88, 89-91, 92 - 93 , 94 and 95 here's link to pics of them - http://www.hotrodlane.cc/throttlebody/throttlebody.html

I doubt there's much difference, probably just the throttle linkage and /or vacuum port

S'nut

86er · « **Reply #6 on:** April 06, 2005, 07:49:14 PM »

Yeah I know the duties are rediculus, where did you you did you get the weatherstrip kit from & what was the quality like, aftermarket of genuine?

Stingraynut · « **Reply #7 on:** April 06, 2005, 11:17:13 PM »

I got the weatherstrip and steering wheel from Contemporary Corvette - http://www.contemporarycorvette.com

The weatherstrip appears to be good and was highly recommended by good guys on the Corvette Forum. Got the views of several people who have used it and they reported good results and longevity. Just post a question there and you should soon have some info on the quality.

I haven't fitted any of it yet because I'm doing a slow think about a respray. I ordered because the Aussie dollar was so good at the time and they had a special on a full kit. I also bought the door/windows strips too - then the Aussie dollar went even higher - luckily this order was not hit for duty. ;41

The other reason the w'strip isn't fitted yet is that I only have one leak - and it's BAD - it's taken me a long time to work out what it might be - the join between the side roof rubber and the side of windscreen rubber - it's fine in ordinary rain, hardly a drip, but in the Cairns Wet Season I was getting something like the flow from a garden hose turned on about 25%.

I was reminded that they also make swimming pools out of fibreglass. I want to be very sure when I glue the new w/strip on that I get it right and cure problems like that.

S'nut

Stingraynut · « **Reply #8 on:** April 06, 2005, 11:27:13 PM »

I see Contemporary Corvette are now on ebay - here's a link to the complete weatherstrip kit US$399 http://www.contemporarycorvette.com

S'nut

Stingraynut · « **Reply #9 on:** May 06, 2005, 08:02:46 AM »

I fitted the new throttlebody yesterday - all is now smooth!!!! It probably feels no better than a new one, but it will last forever!

I normally don't report success so quickly but in this case I can't see that anything will go wrong now - so it's a big thumbs up for David Koldos and my new improved TB

The TB comes bare and all plates TPS and IAC have to be transferred over - I bought a complete gasket set from D Koldos. Then the base idle and TPS voltage have to be set - as per the tech tip by Lars Grimsrud on the Corvette Forum.

I did this procedure last year and it made a big difference - the base idle was way off which I think then upsets the TPS setting etc.

S'nut

86er · « **Reply #10 on:** May 06, 2005, 12:23:30 PM »

Glad it worked out for you

Stingraynut · « **Reply #11 on:** March 23, 2006, 10:15:21 AM »

Just found this old post of mine - I posted results after only a short drive so now confirming that the D Koldos TB with sealed bearings is still working fine, almost a year later.

I had a problem at one stage with a sticky throttle but it turned out that a mechanic had put the throttle cable on the cruise peg and vice versa!!!! Idiot

S'nut