Starting line hesitation - Page 2

Mike Pearson · 07-13-2015, 11:50 AM

Quote:

Originally Posted by Monte Howard

Since Danny built it, I am ruling out the air door to loose. I would try a new choke pull-off, I have had several of them go bad and cause the same issue. Pull the vacum hose off and push the arm in, with the arm pushed in hold your finger over the vacum port. Let go your finger off the vacum port and make sure the arm comes out smoothly. If it starts coming out and then hangs up for a second it's bad.

Let us know if you figure out the stumble in your carb. We have a Danny Ashley prepared Q jet that does the same thing and we have not been able to get it fixed. It's a real nice carb and Danny does nice work so we would realy like to get it running right.

DIV3CR · 07-13-2015, 12:42 PM

In the instruction from Danny that come with The carb it said
that the brass plate fit in a machine groove in the carb top
and I have double check the plate and it is in the groove.
If I find a answer I will post it.
Thanks for everybody's help
Bob Keller

njk53 · 07-13-2015, 12:52 PM

Don't you guys think 6 psi. of fuel pressure is a bit low? We had a Dean Oliver prepared carburetor and currently have a Hedworth prepared unit and we ran both carbs. at 7 psi. and both perform nicely. Is it possible momentary fuel starvation is occurring considering a Q-Jets float bowl is so small?
Just a thought.

Mike Semeniuk · 07-13-2015, 01:26 PM

Fuel Pressure is related to the size of needle and seat, and float settings and of course demand. I need to run mine at 5.5 for best operation , anything over 6 and - too many issues

Mike Pearson · 07-13-2015, 01:37 PM

Quote:

Originally Posted by Mike Semeniuk

Fuel Pressure is related to the size of needle and seat, and float settings and of course demand. I need to run mine at 5.5 for best operation , anything over 6 and - too many issues

Mine runs good at 6 lbs too.

Cdncarnut · 07-13-2015, 02:00 PM

I am running a Joe Scott at 7 psi with no issues.
My Ashley was also running at that same pressure.

HandOverFist · 07-13-2015, 02:09 PM

I have run ours at pressures of 6 to 7.5psi without issue...currently at 6.5psi.

Mark Yacavone · 07-13-2015, 06:29 PM

I'm really not getting how you could bind up that secondary plate deal.
The last thing you would do is set the metering rod tips down into the fixed jets.At that point the hanger would be down flat on the cam arm. You can slide the whole deal fore and aft to check everything before you put the hanger screw in place.

Danny did a nice job on that deal. I never did get that fancy. I just took a small chunk of a Walmart bag and cut a couple of x's in it, then stuck it down to the gasket with a spot of chewing gum until I got the top was screwed on.
That works fine ,and doesn't restrict or bind the swing of the rods like the old tape trick did.

Joe DeMarzo · 07-13-2015, 07:41 PM

Just in case... check the accelerator pump. Every time mine hesitates or stumbles off the line the gasket is dried out from sitting, torn or worn out and doesn't seal because of VP eating at the gasket. Q-Jets do not like a lot of fuel pressure so 6 to 7.5 is fine. You can play with that but not is why it is hesitating in my opinion. Let us know so we can learn, Q-Jet are great but can make you crazzzzy.

Mike Taylor 3601 · 07-14-2015, 08:28 AM

I would say your gasket is bad like Joe said, or needle and seat is leaking. My car has done that before,finally figured out it was needle and seat, I have them leak,but they don't pour fuel out of it,they will leak slightly,car will idle about 200-300 rpm slower,and bogs a few feet out.
The best test I have come up with is remove top and hold float pivot rod with your finger so float works like the top is on carb,then have someone turn on fuel pump, after needle and seat closes watch fuel level in bowl for 1-2 minutes,it should not creep any higher up at all,it may take a minute and if leaking will rise very slowly, be careful sometimes when first turn on pump it will spray fuel out,I usually use my other hand as a shield over carb,till it calms down.
The best thing I have found to prevent this problem is to run carb dry and pump fuel out of tank when I get down racing and store the car,even for one week.
Mark,
I still use the tape trick, I use 3M super33 tape is a soft and flexible electrical tape.

Mike Taylor 3601

07-13-2015, 12:42 PM	#12
DIV3CR Junior Member Join Date: Oct 2011 Location: WISCONSIN Posts: 50 Likes: 0 Liked 3 Times in 1 Post	Re: Starting line hesitation In the instruction from Danny that come with The carb it said that the brass plate fit in a machine groove in the carb top and I have double check the plate and it is in the groove. If I find a answer I will post it. Thanks for everybody's help Bob Keller

07-13-2015, 12:52 PM	#13
njk53 Senior Member Join Date: Jul 2007 Location: East China, MI Posts: 504 Likes: 0 Liked 0 Times in 0 Posts	Re: Starting line hesitation Don't you guys think 6 psi. of fuel pressure is a bit low? We had a Dean Oliver prepared carburetor and currently have a Hedworth prepared unit and we ran both carbs. at 7 psi. and both perform nicely. Is it possible momentary fuel starvation is occurring considering a Q-Jets float bowl is so small? Just a thought. __________________ Nelson Kowal Stock 345 Last edited by njk53; 07-13-2015 at 12:56 PM.

07-13-2015, 01:26 PM	#14
Mike Semeniuk Junior Member Join Date: Aug 2004 Location: Sherwood Park, Alberta Posts: 99 Likes: 19 Liked 6 Times in 2 Posts	Re: Starting line hesitation Fuel Pressure is related to the size of needle and seat, and float settings and of course demand. I need to run mine at 5.5 for best operation , anything over 6 and - too many issues __________________ Mike Semeniuk 632 GTMA

07-13-2015, 02:00 PM	#16
Cdncarnut Member Join Date: Jul 2012 Posts: 213 Likes: 386 Liked 56 Times in 31 Posts	Re: Starting line hesitation I am running a Joe Scott at 7 psi with no issues. My Ashley was also running at that same pressure. __________________ Thomas NHRA 1959 D/SA

07-13-2015, 02:09 PM	#17
HandOverFist VIP Member Join Date: Oct 2013 Location: Gulf Breeze, FL Posts: 1,651 Likes: 8 Liked 33 Times in 16 Posts	Re: Starting line hesitation I have run ours at pressures of 6 to 7.5psi without issue...currently at 6.5psi. __________________ Rich Taylor I/SA - 321

07-13-2015, 06:29 PM	#18
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,815 Likes: 2,903 Liked 5,120 Times in 1,951 Posts	Re: Starting line hesitation I'm really not getting how you could bind up that secondary plate deal. The last thing you would do is set the metering rod tips down into the fixed jets.At that point the hanger would be down flat on the cam arm. You can slide the whole deal fore and aft to check everything before you put the hanger screw in place. Danny did a nice job on that deal. I never did get that fancy. I just took a small chunk of a Walmart bag and cut a couple of x's in it, then stuck it down to the gasket with a spot of chewing gum until I got the top was screwed on. That works fine ,and doesn't restrict or bind the swing of the rods like the old tape trick did. __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

07-13-2015, 07:41 PM	#19
Joe DeMarzo Senior Member Join Date: Oct 2002 Location: Mahopac, NY Posts: 666 Likes: 48 Liked 113 Times in 9 Posts	Re: Starting line hesitation Just in case... check the accelerator pump. Every time mine hesitates or stumbles off the line the gasket is dried out from sitting, torn or worn out and doesn't seal because of VP eating at the gasket. Q-Jets do not like a lot of fuel pressure so 6 to 7.5 is fine. You can play with that but not is why it is hesitating in my opinion. Let us know so we can learn, Q-Jet are great but can make you crazzzzy. __________________ Joe DeMarzo 1317 STK Last edited by Joe DeMarzo; 07-13-2015 at 07:43 PM. Reason: update

07-14-2015, 08:28 AM	#20
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,371 Likes: 352 Liked 304 Times in 102 Posts	Re: Starting line hesitation I would say your gasket is bad like Joe said, or needle and seat is leaking. My car has done that before,finally figured out it was needle and seat, I have them leak,but they don't pour fuel out of it,they will leak slightly,car will idle about 200-300 rpm slower,and bogs a few feet out. The best test I have come up with is remove top and hold float pivot rod with your finger so float works like the top is on carb,then have someone turn on fuel pump, after needle and seat closes watch fuel level in bowl for 1-2 minutes,it should not creep any higher up at all,it may take a minute and if leaking will rise very slowly, be careful sometimes when first turn on pump it will spray fuel out,I usually use my other hand as a shield over carb,till it calms down. The best thing I have found to prevent this problem is to run carb dry and pump fuel out of tank when I get down racing and store the car,even for one week. Mark, I still use the tape trick, I use 3M super33 tape is a soft and flexible electrical tape. Mike Taylor 3601