69 mm tb problems

[Ghost93]

I've had a 69mm throttle body for a while now and I just put it on. When I first started the car the Idle jumped up to about 2500 rpm for about 20 seconds, and then came down to about 1100 where it usually is. After I took the car out for a test beating the idle stays at around 1500 rpm all the time now. Also while moving with the clutch in the idle surges really bad now. It always surges, but not this bad. I'm not sure if the idle screw is in a different place on this TB, and if it is how long would it take the computer to adjust? Any ideas or should I take this thing back off? Thanks in advance, Kevin.

 

[Eric VerValin]

Yea its all outta whack.... when I put mine on... I set the screw just to where it was "closed" or just before maybe... but only like 1/8th of a turn... then you need to reset the idle memory in the computer.... gotta disconnect the ground from the ECU, or pull the battery cable for a while... then when you reconnect it, your supposed to start the car, turn on everything, lights, a/c, fan on high, rear def, radio... then when the idle comes back down to its normal range, take it out and show it a few WOT events, shut her down, and restart and it should have relearned itself.


PS... do it on a warmed up engine... seems to work better I found..


PSS.... what throttle plate do you have? is it one made for it? or are you using a stock one.. if its a stocker I would imagine it would be real hard to keep it idling nice... I dunno

 

[Ghost93]

Its a new plate. The car is tuned with an LPM, is that going to be a problem with relearning the idle?

 

[Ishodu]

With the car at normal op temp unplug the IAB vavle and see if the car stalls and if it doesn't see what the car idles at with it unplugged. This will test too see how much that TB is leaking by.

 

[Eric VerValin]

Nope, shouldn't be.. I got one of those too.. I had to hold mine up to the light when I centered my plate in there to get it just right.... so if your pretty sure she's tight, and you let it relearn itself... if there is still an idle issue.. its gotta be that IAC, or a dirty intake / IAC passages.. possibly a loose vac hose also.. thats what I'd be looking for anyway..

I wanna put some clamps on my butteryfly valve vac lines, because it looks like they shrank a little and should be clamped in place...

 

[jayro]

I also have had some idle issues with my 69mm. It seems to idle fine, but after some wot pulls my idle will bounce. If I turn off the car and restart it the idle is smooth agian. Already searched all over for vac leaks with no success. Gonna clean the iab next. I've heard from a couple of other people with 69's that had idle issues.....wonder if it's just the nature of the beast?

 

[Phoenix]

I also have had some idle issues with my 69mm. It seems to idle fine, but after some wot pulls my idle will bounce. If I turn off the car and restart it the idle is smooth agian. Already searched all over for vac leaks with no success. Gonna clean the iab next. I've heard from a couple of other people with 69's that had idle issues.....wonder if it's just the nature of the beast?

I got that exact issue on my 75mm TB, once in awhile it will bounce and come back to normal. I tried to fix it with the tweecer without any succes.

 

[jayro]

I'm gonna clean everything up real well and try readying the idle. Hopefully it will iron it's self out. The bigger tb must reek havoc with the iab system.

 

[SinisterSHO]

Whatever the issue is, I think the answer is to put a stocker back on, and drive it to the convention.

 

[jayro]

Whatever the issue is, I think the answer is to put a stocker back on, and drive it to the convention.

I'd like to hit the convention, but I don't think it will happen this year.

 

[Ghost93]

Whatever the issue is, I think the answer is to put a stocker back on, and drive it to the convention.

Yeah, about that. I had to burn up all my vacation when I blew out my knee.

I have interesting results. I pulled the throttle body off and checked it to a light, and sure enough there was plenty of light getting through. So I backed the the idle screw off all the way until the plate was stopping the throttle. I then added about a turn from there. The car runs great, its the first time that the car has ever not idle surged. But now the idle is so low, about 600-700 rpm, that now it sometimes stalls as a result of the aluminum flywheel. And in addition the car has a very lopey idle due to the cams, sometimes the idle dips so low that the oil pressure light flickers. I took the car out on a long ride and the computer never bumped the idle. It's a bummer because I love that the car doesn't surge, but I'm not comfortable with the low idle. An old hot rodder at work suggested drilling an 1/8 hole in the plate for more flow, and then put a bolt in the hole if the results are unfavorable. I don't know, if this thing wasn't painted to match the intake I would have canned it already.

 

[jayro]

Did you do thi idle reset procedure after this? What happens if you open it just a touch more? Opening the throttle a touch more would have the same effect at drilling a hole in the plate.....just let's more air by.

 

[Ghost93]

Did you do thi idle reset procedure after this? What happens if you open it just a touch more? Opening the throttle a touch more would have the same effect at drilling a hole in the plate.....just let's more air by.

Yes I did the idle reset. I did open the throttle a little more, and it didn't help much. I going to try to open it some more and see what happens.

 

[speedysprocket]

This sounds like a great mod. Since i have a y-pipe on order, I need to start working on the intake side of things. Where can I get one of these?

Thanks!

 

[Ishodu]

IMO its not a great mod it should be used as a last resort to let high powered cars get the air they need. Should be one of the last things to do.
Too many reliability issues arise from the bored out TB for most people to over come.

 

[jayro]

IMO its not a great mod it should be used as a last resort to let high powered cars get the air they need. Should be one of the last things to do.
Too many reliability issues arise from the bored out TB for most people to over come.

X2. This would be one of the last things I would do. Probably only see benefits in a full bolt on sho with cams.