Hanging idle after throttle body install

07GtS197 · Jul 31, 2016

Hey guys, recently I swapped in a generic 75mm tb and ever since Ive had a hanging idle when coming to a stop. I reset the computer and checked for binding but neither had any effect. I know bbk tb's are know for this and it looks like a knock off bbk (its an ebay special) so it could have that problem too I guess. Any ideas? Im going to reinstall the tps, maybe its not sitting flat?

On a side note, Im swapping my drivers side front caliper and I have abs. Will I run into any problems bleeding the brakes afterwards? My 00 gt had the same caliper lock up after a brake install, it seems like a common problem on these cars. What causes it though? Is it the caliper itself or something else like the brake lines collapsing?

Frank.JD.Perez · Jul 31, 2016

im guessing youre talking about the 99 04 twin piston pbr calipers right?

any updates on the tb? i would be kinda cautious around an ebay special but thats just me

07GtS197 · Jul 31, 2016

Yes sorry this is about my 02 gt with the stock pbr calipers. It seems like a common problem but I dont want to replace the caliper if its not the problem. Ive read it could also be the hydroboost going out. Yay.

No I havent done anything to the tb yet I need to get the brakes done then I can test it on the street. Theres nothing wrong with the tb but it does have the same issue that the bbk's have. Maybe theres a common design flaw or maybe because Im on the factory tune, I dont know. Ill reseat the tps on the tb and see if that has any effect. I remember when installing it, the tps wouldnt sit flush, close but not all the way. It was a nightmare to install and I just wanted it done so I left it.

Frank.JD.Perez · Jul 31, 2016

07GtS197 said:
Yes sorry this is about my 02 gt with the stock pbr calipers. It seems like a common problem but I dont want to replace the caliper if its not the problem. Ive read it could also be the hydroboost going out. Yay.

No I havent done anything to the tb yet I need to get the brakes done then I can test it on the street. Theres nothing wrong with the tb but it does have the same issue that the bbk's have. Maybe theres a common design flaw or maybe because Im on the factory tune, I dont know. Ill reseat the tps on the tb and see if that has any effect. I remember when installing it, the tps wouldnt sit flush, close but not all the way. It was a nightmare to install and I just wanted it done so I left it.

id say go over the tb again to make sure its all together. i doubt a tune/stock set up will be making a difference like that, but i could be wrong. and im trying to remember my pbr upgrade when i did it... i dont really remember any issues like what youre having, but they did have a lot of dust which totally fvcked up my 98 cobras that i had. if i were you i would upgrade to the 13 in cobra style. since youre in florida you should be able to find a full set for relatively cheap, and its a total worth while upgrade.

ttocs · Jul 31, 2016

its a common problem when you swap tb's. Some have a screw on the top that you can adjust to slow the air the idle air control gets and some do not. A lot of people do a band aid fix and make an aluminum plate with a hole as a restrictor to slow it down. There was a piece made that went before the idle air that has two screws you adjust to get it right but it is not cheap for the small piece it is

07GtS197 · Jul 31, 2016

I went over everything again and all seems well, nothing out of place nothing loose... The tps is sitting correctly, it was the bottom screw that wont sit all the way. Ill reset the battery again to see if the idle just needs to be reset. When I datalogged earlier under the tps open/closed it said learning so Im guessing it still needs a few drive cycles.

As far as the cobra brakes, Id love to upgrade but Im on a budget now. Im going to swap the calipers and lines with a new set I have lying around and flush the brake fluid entirely. The car sat before I bought it and the front calipers kept sticking, among other problems. Id take the tires off and work them free so they would slide freely on the slide pins. The passanger side caliper is fine its just the drivers side is locking up and its not the slide pins being dry.

My iac doesnt have a screw and its not that big of a deal so I wont mess with it for now. Thanks.

Nighttrain · Aug 2, 2016

That plate is easy to make if it continues to bug you. You will probably get a hanging idle to. Caliper rebuild kits are cheap and easy tk do. Probably had water collect in the system and corroded the pistons. Whatever you do id flush it. Make sure there's no junk in there from sitting.

07GtS197 · Aug 2, 2016

I just found a resistor plate on ebay for 6 bucks. Ill get it and see how it goes.

As far as the brakes, if thats the case then our calipers are prone to corrosion. Ive read so many articles about the 99-04 v6/gt calipers locking onto the rotors its crazy. I had the drivers side front caliper lock on my 00 gt and now the very same caliper is going the same thing on my 02 gt. What I want to know is what the common cause is. Like I said I have another set Ill install with a flush and go from there. I bought 2 rebuild kits a while ago, Ill rebuild my old calipers either to sell or as backup if/when these ones Ill be installing fail.

ttocs · Aug 2, 2016

I have a set of cobra calipers I need to sell. I would be willing to make a good deal on them as they need to be put back together but they have been freshly powder coated.

07GtS197 · Aug 3, 2016

Nighttrain · Aug 4, 2016

07GtS197 said:
I just found a resistor plate on ebay for 6 bucks. Ill get it and see how it goes.

As far as the brakes, if thats the case then our calipers are prone to corrosion. Ive read so many articles about the 99-04 v6/gt calipers locking onto the rotors its crazy. I had the drivers side front caliper lock on my 00 gt and now the very same caliper is going the same thing on my 02 gt. What I want to know is what the common cause is. Like I said I have another set Ill install with a flush and go from there. I bought 2 rebuild kits a while ago, Ill rebuild my old calipers either to sell or as backup if/when these ones Ill be installing fail.

Yes they are prone to it. First break fluid, like any other chemical/hydraulic fluid/lubricant has a certain life span. Normal maintance is flushing and replacing said fluid. Normal everyday use, heating and cooling will cause moisture to accumulate even in a closed/sealed system. Heat is probably the biggest cause of this. That moisture will then cause corrosion and so forth. But anyway, if you got the rebuild kits already, plus extra calipers swap em, rebuild em, and if you gets Scotts cobra's swap the gt fronts to the rear. That would make a killer brake set up my man.

07GtS197 · Aug 4, 2016

Nighttrain said:
Yes they are prone to it. First break fluid, like any other chemical/hydraulic fluid/lubricant has a certain life span. Normal maintance is flushing and replacing said fluid. Normal everyday use, heating and cooling will cause moisture to accumulate even in a closed/sealed system. Heat is probably the biggest cause of this. That moisture will then cause corrosion and so forth. But anyway, if you got the rebuild kits already, plus extra calipers swap em, rebuild em, and if you gets Scotts cobra's swap the gt fronts to the rear. That would make a killer brake set up my man.

That would be sweet! I have another set of s197 gt calipers laying around I wanted to swap on but 18 inch rims are not in the cards for a while but cobras will clear the stock 17 inch bullitts. And the added braking performance is just icing on the cake lol.