A Stumble

[nickygn23]

Hey guys, a little help please, by the way 'Go Giants'..
I'm having a little problem.. Its really a two part problem .First if I grab the throttlebody and if I spin it up too fast the engine will stumble a little then catch.Thats mostly when its cold. Not so bad under running temp. Second part of the problem. When I grab the throttlebody and rev up the motor then release the throttlebody it seams like it going to stall when it hits the bottom revs then catchs at the last minute.This is driving me crazy. Please help. Here are my #s
AF=08
L8=53
BAT=13.4
INT=123
BL=129
CLT=201
ATS=140
R=1300
TPS=44
IAC=00
CC=03 and rises
MAL=00

 

[fastblackttype]

thats steaming from your maf sensor its too high at 08 its supposed to be between 4 and 6 .You have to ajust it and your temp is alittle too high.

 

[nickygn23]

I'm running a stock M.A.F. Not sure if I can adjust that.

 

[fastblackttype]

go to a site that is called vortex buicks .com there you will get a better understanding for your buick , it will also show you how to adjust your maf with your scanmaster.

 

[Blazer406]

looks like you need to back off the throttle screw until iac's get around 25. Then re-adjust TPS to .46.

You need to verify the TPS doesn't have a dead spot........ it could be causing a stumble......

 

[nickygn23]

I get how to adjust the Throttle screw. Right now I have a reading of 42. I'll turn it counter clockwise a thread or two to bring it down to 25 then shut it off and restart to save correct? One question ... how do you re-adjust the TPS? I'm still learning. Only had my car a year and just got my scanmaster. Been reading up on all stuff related to scanmaster. My eyeballs hurt from reading.
Thanks

 

[Blazer406]

Set the scanmaster to show IAC......then when the engine is hot idling....... back off the throttle screw a turn or so....let it sit idling for 15 sec or so......observe the IAC number in the scanmaster.......keep tweaking the throttle screw and waiting 15 sec or so before you read the scanmaster.......try and get the IAC between 20 and 30. Once you get the value there........set the scanmaster to show TPS....... loosen the two screws on the tps a little....bump the snout of the tps where the connector is either up or down......see what the TPS value does on the scanmaster........keep tweaking until you get it to .44-.46. You should be set then.......

HTH

 

[nickygn23]

I just broke the little arm off the throttle body the hits the T.P.S !@#$$%^&*(*&^^%%$#@@!!!!!!!!!!!!!!!

 

[nickygn23]

Can I repair this or rebuild the throtlle body.... GGGRRRRR maybe drill out the broken piece and retap it..... Buying a new throttle body is the last resort.. I'd rather repair it. Any ideas?

 

[nickygn23]

Another picture

 

[lost2a6]

If you want to bring the IAC # down, you turn the screw clockwise and open the throttle plate, then readjust the TPS sensor. The less the IAC #'s are, the computer is calling for less air through the IAC to maintain idle RPM.

 

[Blazer406]

If you want to bring the IAC # down, you turn the screw clockwise and open the throttle plate, then readjust the TPS sensor. The less the IAC #'s are, the computer is calling for less air through the IAC to maintain idle RPM.

In his original post, the IAC was already"00", so it needed to come up......

 

[Blazer406]

Can I repair this or rebuild the throtlle body.... GGGRRRRR maybe drill out the broken piece and retap it..... Buying a new throttle body is the last resort.. I'd rather repair it. Any ideas?

You should be able to pick you up a used one on here pretty reasonable.......sorry for the bad luck......

 

[nickygn23]

Fixed the throttlebody.Now I tried to fix the stumble.I set the I.A.C to 25 I think it was. Perfect.Then I set the T.P.S to 44. The motor sounded like pure Rock and Roll. No Hesitation... No Stumbles then I took it for a ride..... Perfect. Brought it home ,shut it off and restarted it just to check and apon restart it reset back. Ran Like crap again.... I don't get it. I brought it back to the sweet spot settings three times and when I shut it off and started it same result. The I.A.C would read 00. Baffled.

 

[Blazer406]

You might have a bad IAC motor. It has been my experience if the idle isn't fairly steady... and the IAC numbers at hot idle aren't fairly steady..... you need to look hard toward the IAC motor. Maybe someone can help me confirm this.

Sounds like you are headed in the right direction.....

 

[nickygn23]

It was so nice to hear the motor stumble free. Weird huh that it would reset like that. Three times in a row.

 

[blackdeathtrap]

thats good i had same probleme but turned out i had major header leak

 

[nickygn23]

I don't think its a header leak even though my drivers side manifold has a crack. When I set all the numbers prefect T.P.S and I.A.C motor runs amazing but when I turn it off the I.A.C resets to 00.

 

[nickygn23]

Is there a step I'm missing? I want to keep the perfect settings even after I shut off the car. Any Ideas would be apprecaited.

 

[Blazer406]

Is there a step I'm missing? I want to keep the perfect settings even after I shut off the car. Any Ideas would be apprecaited.

I don't think so....Your throttle blade return spring is returning the throttle all the way every time isn't it?

If it is.... you might try a new IAC motor.....