08-21-2015, 11:29 AM | #1 |
Member
Join Date: Jul 2015
Location: Black Hills South Dakota
Posts: 43
|
Gav
I have been playing with the Gas Adjustment Valve tuning for a cooler running engine. I have noticed that opening the valve seems to help run cooler at higher speeds. That I expected. But, when idling if the GAV is open at all the car runs ruff, As soon as a close it it smooths out. I though that the GAV should have no effect on idle, is there something wrong in the carb?
Last edited by Mcb12; 08-21-2015 at 11:30 AM. Reason: Typo |
08-21-2015, 11:44 AM | #2 |
BANNED
Join Date: May 2010
Location: Bucks County, PA
Posts: 11,454
|
Re: Gav
the model A likes to idle low.. make sure your not set to high..
dont use your hand lever to idle the car... set it with the idle stop/ curb idle screw |
Sponsored Links (Register now to hide all advertisements) |
|
08-21-2015, 11:57 AM | #3 |
Member
Join Date: Jul 2015
Location: Black Hills South Dakota
Posts: 43
|
Re: Gav
That makes sense Mitch, I am adjusting the idle with the throttle and it is pulling fuel through CAP jet rather than idle jet. I will give that a try. Thank you.
|
08-21-2015, 12:57 PM | #4 |
Senior Member
Join Date: Jun 2010
Location: New Jersey
Posts: 1,471
|
Re: Gav
Still seems strange though, doesn't it?
Our "A" will idle fine with the GAV cracked some, the same setting we drive it at. Even a fast idle is fine, or any speed for that matter. Mcb12, do you have an air filter and if so which one? |
08-21-2015, 01:11 PM | #5 |
BANNED
Join Date: May 2010
Location: Bucks County, PA
Posts: 11,454
|
Re: Gav
what are you running for a carb and jets?
|
08-21-2015, 01:29 PM | #6 |
Senior Member
Join Date: Jun 2010
Location: New Jersey
Posts: 1,471
|
Re: Gav
|
08-21-2015, 01:32 PM | #7 |
BANNED
Join Date: May 2010
Location: Bucks County, PA
Posts: 11,454
|
Re: Gav
|
08-21-2015, 01:45 PM | #8 |
Member
Join Date: Jul 2015
Location: Black Hills South Dakota
Posts: 43
|
Re: Gav
I do have a filter, an Air Maze with a metal screen. Could that make a difference?
|
08-21-2015, 01:51 PM | #9 |
Senior Member
Join Date: Jun 2010
Location: New Jersey
Posts: 1,471
|
Re: Gav
|
08-21-2015, 01:58 PM | #10 |
BANNED
Join Date: May 2010
Location: Bucks County, PA
Posts: 11,454
|
Re: Gav
|
08-21-2015, 02:25 PM | #11 |
Senior Member
Join Date: May 2010
Location: Portland, Oregon
Posts: 5,903
|
Re: Gav
Mitch, you sure got that right. I've owned over twenty Model A's since 1961, and played with many more, and I can testify there is no standard setting for the carb.
__________________
Ray Horton, Portland, OR As you go through life, keep your eye on the donut, not the hole. |
08-21-2015, 04:39 PM | #12 |
Senior Member
Join Date: May 2010
Location: Sugar Land, TX
Posts: 4,395
|
Re: Gav
I just looked at my recently purchased set of Renner's jets and none of them are numbered. However, all are measured for flow. Two look like reproduction. Two looker original but not numbered.
|
08-21-2015, 04:40 PM | #13 |
Senior Member
Join Date: May 2010
Location: San Diego,Ca
Posts: 1,377
|
Re: Gav
I am thinking the original poster must have a big problem if he is seeing a temperature change on a gauge from running lean, I would think a severe loss of power would be evident first along with engine damage, - you can be close with jet sizes and still have a clean running - idling engine, I buy forever4s statement.
__________________
Nothing can be made foolproof, ---- fools are ingenious bastards. |
08-21-2015, 05:10 PM | #14 | |
BANNED
Join Date: May 2010
Location: Bucks County, PA
Posts: 11,454
|
Re: Gav
Quote:
|
|
08-21-2015, 05:16 PM | #15 |
Senior Member
Join Date: Mar 2015
Location: Acworth GA
Posts: 534
|
Re: Gav
Carburetor is a French word which translates to "Leave it alone".
__________________
Houston, Tranquility base here. The Eagle has landed. |
08-21-2015, 05:18 PM | #16 |
Member
Join Date: Jul 2015
Location: Black Hills South Dakota
Posts: 43
|
Re: Gav
I started this thread because I had read that the GAV should not affect Idle, yet it does in my car, even when I have the idle as low as it will go without stalling the engine. But, I have also read an article on Carbs (Model A Basics site) that the GAV does little to affect gas flow once higher RPM are reached, in fact it states that you should use the GAV to lean the mix for fuel economy. Am I missing something here. In my 31 the GAV has a tremendous effect on fuel mixture at all speeds. I may have a separate issue with overheating but the the fuel mixture is still perplexing to me. My plugs look great is there another way to determent if and when I am running lean or rich, behond the obvious, backfire.......
|
08-21-2015, 05:21 PM | #17 |
Senior Member
Join Date: Mar 2015
Location: Acworth GA
Posts: 534
|
Re: Gav
The GAV affects engine running at all speeds in my car. I read somewhere to turn the GAV richer for starting and warmup, which I do with definite effect. (Standard Zenith with Hi-Boy air cleaner)
John
__________________
Houston, Tranquility base here. The Eagle has landed. |
08-21-2015, 05:31 PM | #18 | |
Senior Member
Join Date: Dec 2010
Location: FRESNO, CA
Posts: 12,560
|
Re: Gav
Quote:
Bill W.
__________________
"THE ASSISTANT GURU OF STUFF" |
|
08-21-2015, 05:46 PM | #19 |
Member
Join Date: Jul 2015
Location: Black Hills South Dakota
Posts: 43
|
Re: Gav
thanks Bill I will look at that.
|
08-21-2015, 09:30 PM | #20 |
Senior Member
Join Date: May 2010
Location: Between Seattle & Tacoma
Posts: 2,354
|
Re: Gav
You're idling too high
|
|
|
Sponsored Links (Register now to hide all advertisements) |
|