Slow Return to Idle

Reply Subscribe

Thread Tools

Search this Thread

Dec 27, 2011 | 01:33 PM

#16

cbass139

Thread Starter

Senior User

Joined: May 2009

Posts: 382

Likes: 0

From: Chicago

Ross, power valve that was changed last spring to match the vacuum I was getting and because it was torn. I hope it isnt that again, would rather not have to take it off the truck again. I dont have power anything so the only vacuum line is to the dizzy so I will take a look at that and see if I need to replace it. I will be checking for the usually leaks with a can of cleaner, almost hope it is something like that and thus I can fix it during my week off of work starting tomorrow.
Thanks again guys
Cbass

Dec 27, 2011 | 03:23 PM

#17

ALBUQ F-1

Fleet Owner

Joined: Jul 2004

Posts: 27,294

Likes: 1,055

From: NM

In Chicago, you should be running the stock (usually) 7.5 power valve. What one are you running?

Dec 27, 2011 | 03:26 PM

#18

cbass139

Thread Starter

Senior User

Joined: May 2009

Posts: 382

Likes: 0

From: Chicago

That is what I put in it (I believe, would have to look it up to be positive), the truck came from florida and I went with what ever the Holley rep. that I spoke with on the phone said would work best. I am not a carb expert but I can follow directions, that is why I love this site. Keep steering me in the right direction and I will get there.

Dec 27, 2011 | 03:40 PM

#19

3golfjack

Laughing Gas

Joined: Nov 2006

Posts: 1,125

Likes: 4

From: Olive Branch,Ms

May sound crazy but after it warms up check to make sure the choke is opening correctly. My truck has a manual choke and until I back the choke back off after starting, it will not idle down. ( my is a holley carb )

Dec 27, 2011 | 04:16 PM

#20

bobbytnm

Roast em' if you got 'em

Joined: Mar 2005

Posts: 21,997

Likes: 9,885

From: Rio Rancho, NM

Is that one of the carbs that prone to tearing a power valve when you get a backfire?

If he only vacuum line you have is a ported line to the dizzy then its probably not the source of your vacuum leak....it would only have vacuum on acceleration and not at idle.

....but....does the carb have a big open hole in the rear of the baseplate.....maybe where a 3/8 line once ran to a power brake booster on a different application?....maybe that would be plugged off? (I once dealt with that on a friends car as well...LOL)

Bobby

Dec 27, 2011 | 04:55 PM

#21

homade

Cargo Master

Joined: Nov 2007

Posts: 2,292

Likes: 8

From: sparta ky.

Take a windex bottle and put some dish washing soap and water in it and spray around the base of the carb and around all lines, if you have a vacumn leak it will suck the soap suds and u can find the leak. Be sure to spray around the throttle shaft because they can leak also, Garry

Dec 28, 2011 | 11:44 PM

#22

cbass139

Thread Starter

Senior User

Joined: May 2009

Posts: 382

Likes: 0

From: Chicago

Got it running great thanks to a lot of great advice. I just started over after making sure there was no mechanical problems (butterfly, linkage, choke) but the return spring was a bit weak to I replaced it and then started tuning from step one by vacuum gauge. I got it so that girl is running better then it has since I have owned her. The obvious things that needed fixing were the accelerator pump was adjust wrong (even after that is what I did over the weekend) and the idle screws were out too far. Not sure it was any one problem that caused the bad idle or just the combo of all of them but thanks to all that helped our.
Regards,
Cbass

Dec 29, 2011 | 08:43 AM

#23

bobbytnm

Roast em' if you got 'em

Joined: Mar 2005

Posts: 21,997

Likes: 9,885

From: Rio Rancho, NM

Excellent!!
I'm glad you got it dialed in. There's been many a time when I've been totally frustrated trying to get somthing to run right. Sometimes you have to walk away for a day or two and then start from scratch.

Now get out there and enjoy the ride
Bobby