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Hesitation ??

Posted By: Stroker Scamp

Hesitation ?? - 01/23/15 07:12 AM

Can an ignition issue cause the motor to stall or hesitate on a rapid full throttle whack?
Reason I ask is I have tried 3 different carbs on the same motor (stockish 340)same results.
The new carb is a 750 DP, been tuning it and its getting better but I think some thing else may be the culprit
Posted By: ademon

Re: Hesitation ?? - 01/23/15 07:15 AM

could be as the cyl psi quickly rise, check to make sure your pickup to reluctor gap is at.008,
Posted By: Cab_Burge

Re: Hesitation ?? - 01/23/15 08:58 AM

Is the vacume advance hooked up? If so try disconnecting it and see if that helps or not
Posted By: MR_P_BODY

Re: Hesitation ?? - 01/23/15 04:07 PM

You make sure that the timing is set right first...
then start on the carb.. make sure the pump arm and
pump start a shot when you move the throttle.. then
its how much
Posted By: Crizila

Re: Hesitation ?? - 01/23/15 05:01 PM

Quote:

Is the vacume advance hooked up? If so try disconnecting it and see if that helps or not

- after 3 carbs, it's time to start looking at something else. Ignition timing would be a good next step. I have several distributors for sale - - - ok, just kidding.
Posted By: Quicktree

Re: Hesitation ?? - 01/23/15 06:25 PM

you could put 10 carbs, if the pump shot is not right it will do the same thing. timing should be set and right before you adjust the carb.
Posted By: Dabee

Re: Hesitation ?? - 01/24/15 01:13 AM

I had the same problem with the 511 in my 69 Bee. I checked/tried everything and the hesitation was still always there. It was driving me nuts. Then I found a station near the house that sold 100% 93 octane gas. I started using that instead of the 10% ethanol crap and the hesitation went a way. May not solve your problem, but it is worth a try if you have access to 100% 92 or 93 octane.
Posted By: Crizila

Re: Hesitation ?? - 01/24/15 01:53 AM

Quote:

you could put 10 carbs, if the pump shot is not right it will do the same thing. timing should be set and right before you adjust the carb.

I went with the odds! 10 Carbs with focked up pump shots would be - rare.
Posted By: Quicktree

Re: Hesitation ?? - 01/24/15 09:45 AM

Quote:

Quote:

you could put 10 carbs, if the pump shot is not right it will do the same thing. timing should be set and right before you adjust the carb.

I went with the odds! 10 Carbs with focked up pump shots would be - rare.

sure you did, the chances of any carb being right the first time for any given combo unless it's specifically set up for it are slim I would think.
Posted By: Thumperdart

Re: Hesitation ?? - 01/24/15 05:00 PM

Quote:

Quote:

Quote:

you could put 10 carbs, if the pump shot is not right it will do the same thing. timing should be set and right before you adjust the carb.

I went with the odds! 10 Carbs with focked up pump shots would be - rare.

sure you did, the chances of any carb being right the first time for any given combo unless it's specifically set up for it are slim I would think.



Maybe in days of old AND some new where the brilliant whackos added more holes than swiss cheese and you musta missed the last thank you post. Bolted it on and raced NO adjustments...............Doesn`t happen everyday but when set up PROPERLY they can be real close. Too bad you didn`t send me yours so you could experience the same things.......
Posted By: Quicktree

Re: Hesitation ?? - 01/24/15 05:21 PM

Quote:

Quote:

Quote:

Quote:

you could put 10 carbs, if the pump shot is not right it will do the same thing. timing should be set and right before you adjust the carb.

I went with the odds! 10 Carbs with focked up pump shots would be - rare.

sure you did, the chances of any carb being right the first time for any given combo unless it's specifically set up for it are slim I would think.



Maybe in days of old AND some new where the brilliant whackos added more holes than swiss cheese and you musta missed the last thank you post. Bolted it on and raced NO adjustments...............Doesn`t happen everyday but when set up PROPERLY they can be real close. Too bad you didn`t send me yours so you could experience the same things.......

lol I don't have any problems with mine. it runs great and repeats
Posted By: Thumperdart

Re: Hesitation ?? - 01/24/15 05:26 PM

That`s what most "Bracket racers" say...............
Posted By: Dodgem

Re: Hesitation ?? - 01/24/15 11:12 PM

If your running a power valve with too low a number will do that. I like them 1.5 under in gear idle vacuum. Seems now days where carbs used to come with 6.5's or higher they are 4.5 helps take tunning for dummies with a cam out of equation.
Posted By: Stroker Scamp

Re: Hesitation ?? - 01/24/15 11:33 PM

Thanks for all the ideas, finally stopped raining so I will tweak it a bit and let you know.
Posted By: Thumperdart

Re: Hesitation ?? - 01/25/15 12:01 AM

Quote:

If your running a power valve with too low a number will do that. I like them 1.5 under in gear idle vacuum. Seems now days where carbs used to come with 6.5's or higher they are 4.5 helps take tunning for dummies with a cam out of equation.



NEGATIVE..........Doesn`t work that way unless you`re WAY into the transition on the primaries cos when the idle`s correct you can remove the jets w/no change. As far as p/v sizing, take a drive at a steady rate or slight load, look at that # then maybe drop down 1-2 for power enrichment..........
Posted By: Quicktree

Re: Hesitation ?? - 01/25/15 12:07 AM

Quote:

Quote:

If your running a power valve with too low a number will do that. I like them 1.5 under in gear idle vacuum. Seems now days where carbs used to come with 6.5's or higher they are 4.5 helps take tunning for dummies with a cam out of equation.



NEGATIVE..........Doesn`t work that way unless you`re WAY into the transition on the primaries cos when the idle`s correct you can remove the jets w/no change. As far as p/v sizing, take a drive at a steady rate or slight load, look at that # then maybe drop down 1-2 for power enrichment..........

negative that method is for street driving, doesn't work well for a race car. it can and will cause a hesitation. the 1-1.5 HG below idle in gear works best for any race car I have seen. I usually don't run PV's don't need them
Posted By: Stroker Scamp

Re: Hesitation ?? - 01/26/15 06:45 AM

Well didn't have much time today, but took the Duster for a drive still have the full throttle whack hesitation and I have what sounds like a lean miss fire at 2500 RPM
pretty sure this is all not carb related.
Not sure where to look next except ignition
Posted By: Quicktree

Re: Hesitation ?? - 01/26/15 12:26 PM

just for the heck of it change the squirters. go up one size and see if that helps any. I assume you have tried messing with the cams and have that part set up right? put a brown cam on them. you may very well have other problems but make 1 change at a time.
Posted By: Thumperdart

Re: Hesitation ?? - 01/26/15 05:27 PM

Going through this on a guys car and the FIRST thing I suggested was a crank. comp. test and sure enuff he had several low cyls. for whatever reasons cos he hasn`t called back yet. I`d pull all of the plugs and see how they look then check plug wires etc.
Posted By: BIGS

Re: Hesitation ?? - 01/27/15 12:50 AM

Hey Stroker, what is your base/initial timing at idle and how quick are you getting your total in......this is the first place to start.....Jesse
Posted By: CHAPPER

Re: Hesitation ?? - 01/27/15 01:48 AM

Quote:

Hey Stroker, what is your base/initial timing at idle and how quick are you getting your total in......this is the first place to start.....Jesse



Posted By: Stroker Scamp

Re: Hesitation ?? - 02/01/15 06:58 AM

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it

Attached picture 8414787-20140924_203835.jpg
Posted By: Quicktree

Re: Hesitation ?? - 02/01/15 01:43 PM

Quote:

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it

you need to jack that initial up to around 18-22* 10 is not enough imo
Posted By: Thumperdart

Re: Hesitation ?? - 02/01/15 04:22 PM

Quote:

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it



Jetting ISN`T tuning only controlling the VOLUME of fuel............you need to TUNE the emultion well, t-slot jet(u need 1)idle bl, hi etc. You will not be happy until someone who knows what`s up TUNES it for ya or learn how yourself...........you can do it!
Posted By: Quicktree

Re: Hesitation ?? - 02/01/15 04:24 PM

Quote:

Quote:

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it



Jetting ISN`T tuning only controlling the VOLUME of fuel............you need to TUNE the emultion well, t-slot jet(u need 1)idle bl, hi etc. You will not be happy until someone who knows what`s up TUNES it for ya or learn how yourself...........you can do it!

carb tuning doesn't even start until all the basics are taken care of. with 10* initial it has not.
Posted By: Thumperdart

Re: Hesitation ?? - 02/01/15 04:28 PM

I agree about more initial so let`s see how that solves the crappy tunes of carbs today cos I`m sure when he brings it up to where you think it should be, it will be perfect..............
Posted By: MR_P_BODY

Re: Hesitation ?? - 02/01/15 04:43 PM

Quote:

Quote:

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it

you need to jack that initial up to around 18-22* 10 is not enough imo



you have to get the base timing up.. but
your gonna have to curve the dist so you reduce the
total timing to get what you need for max... this was
said earlier on the timing
Posted By: Quicktree

Re: Hesitation ?? - 02/01/15 06:05 PM

Quote:

I agree about more initial so let`s see how that solves the crappy tunes of carbs today cos I`m sure when he brings it up to where you think it should be, it will be perfect..............

maybe not, but im not trying to sell carb tunes either...
Posted By: Stroker Scamp

Re: Hesitation ?? - 02/01/15 07:20 PM

couple of other things
put a vacuum gauge on it and its at 20 at idle and 50 at about 2500.
I agree on getting the timing down first, I have 3 different timing lights and all 3 give slightly different readings, plus the junk dampner marks
This motor is in the Duster, more of a street car

Attached picture 8415254-2012-06-0216.47.02.jpg
Posted By: Quicktree

Re: Hesitation ?? - 02/01/15 07:23 PM

check the vac at idle in gear? are you running PV's?
Posted By: Thumperdart

Re: Hesitation ?? - 02/01/15 08:22 PM

Quote:

Quote:

I agree about more initial so let`s see how that solves the crappy tunes of carbs today cos I`m sure when he brings it up to where you think it should be, it will be perfect..............

maybe not, but im not trying to sell carb tunes either...



IF you knew how you definitely would but talkin and banterin and chest pounding seem to be easier than actually doin something................

By the way, I`m not sellng tune ups I`m selling RESULTS..............
Posted By: mrrandyj

Re: Hesitation ?? - 02/01/15 09:20 PM

Quote:

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it



Your picture shows your timing at 10* AFTER tdc not before. That's 20* from where you think it is.
Posted By: Quicktree

Re: Hesitation ?? - 02/01/15 09:43 PM

Quote:

Quote:

Quote:

I agree about more initial so let`s see how that solves the crappy tunes of carbs today cos I`m sure when he brings it up to where you think it should be, it will be perfect..............

maybe not, but im not trying to sell carb tunes either...



IF you knew how you definitely would but talkin and banterin and chest pounding seem to be easier than actually doin something................

By the way, I`m not sellng tune ups I`m selling RESULTS..............

I am not pounding anything, when I see a direct side by side comparison I will be the first to congratulate you. what puzzles me is all these years you never talked about being a carb guy then all of a sudden you can get .2 form a few tweaks. and maybe so not putting you down in any way. I just want some proof, is that to much to ask? I am not talking about some guys project or one way off. one that runs somewhat well and a thumper tweak back to back results. then I will
Posted By: Thumperdart

Re: Hesitation ?? - 02/01/15 10:11 PM

I don`t NEED to prove anything to you and no longer care if I ever build one for you or not cos it`s those "open minded" people that get it and THOSE are the customers I need and appreciate and funny enuff, they appreciate me back...........
Posted By: Quicktree

Re: Hesitation ?? - 02/01/15 10:23 PM

Quote:

I don`t NEED to prove anything to you and no longer care if I ever build one for you or not cos it`s those "open minded" people that get it and THOSE are the customers I need and appreciate and funny enuff, they appreciate me back...........

ok ok to be honest I wouldn't let just anybody go drilling and messing with my carbs. I hope the best for you. you have a great running car and I always pull for you. I am glad it works for you but I can't help wondering and I am not the only one so good luck don't be mad...
Posted By: Stroker Scamp

Re: Hesitation ?? - 02/01/15 11:04 PM

Quote:

Quote:

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it



Your picture shows your timing at 10* AFTER tdc not before. That's 20* from where you think it is.


That was just a pic to show the 2 marker lines
Posted By: MR_P_BODY

Re: Hesitation ?? - 02/01/15 11:13 PM

Quote:

Quote:

Quote:

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it



Your picture shows your timing at 10* AFTER tdc not before. That's 20* from where you think it is.


That was just a pic to show the 2 marker lines



So which one is zero... you should have marked the
zero when you degreed your cam
Posted By: Stroker Scamp

Re: Hesitation ?? - 02/02/15 12:02 AM

Quote:

Quote:

Quote:

Quote:

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it



Your picture shows your timing at 10* AFTER tdc not before. That's 20* from where you think it is.


That was just a pic to show the 2 marker lines



So which one is zero... you should have marked the
zero when you degreed your cam



Car was bought as is, so I am just getting to know all of its quirks. Who knows if the cam was degreed or not, hopefully so
and GO HAWKS
Posted By: Quicktree

Re: Hesitation ?? - 02/02/15 12:10 AM

Quote:

Quote:

Quote:

Quote:

Quote:

initial is right about 10 and total of right about 35/36.
did wind up putting a A/F meter on it and WOT is at 12.5/13
Cruise is at 12.5, so I will work on jetting
Still has the miss that I think is a ignition issue
Got a dampner that has 2 marks on it



Your picture shows your timing at 10* AFTER tdc not before. That's 20* from where you think it is.


That was just a pic to show the 2 marker lines



So which one is zero... you should have marked the
zero when you degreed your cam



Car was bought as is, so I am just getting to know all of its quirks. Who knows if the cam was degreed or not, hopefully so
and GO HAWKS

got $20 on the Hawks
Posted By: aspenrt360

Re: Hesitation ?? - 02/03/15 05:16 AM

umm you say you have how much vacuum? how big is the cam? and are you sure the breaking up is not a mechanical issue?
Posted By: ademon

Re: Hesitation ?? - 02/03/15 05:38 AM

I've had a lean tip in off cruise if that's what your talking about, this is with three different carbs and now with the mechanical 6
Pack! I've had timing as hi as 22 initial and as low as 10. Also I know my pump shot is instant and have gone as hi as 38 on a 400hp 360. I've always used the idle vacuum in gear and go 2 under my car pulles 7.5" and I have 5.5 PV in it now. Make sure your timing and pump shot is right. The next thing I may try is a PV 1 or 2" under a light cruise and see if that helps.
Posted By: moparpoolman

Re: Hesitation ?? - 02/04/15 01:28 AM

This will not solve all your problems but I think bringing your #1 piston to TDC, rotor pointing to the #1 on the cap will let you know which timing mark you should be using. Once you know, mark it and go off that mark.
Posted By: Stroker Scamp

Re: Hesitation ?? - 02/04/15 05:13 AM

Couple of updates
Vacuum is at 8 at idle in gear
The mark on the dampner that has the arrows is TDC

With the vacuum advance plugged initial is set at 17*
When I raise the RPM up the mark jumps like crazy
but it comes and goes in the 34 to 36 range

put a bigger squirter in and hesitation seem a bit better

Any ideas on correcting the jumping timing mark??
Posted By: ademon

Re: Hesitation ?? - 02/04/15 07:29 AM

Where are you at rpm wise when it starts to jump
Posted By: Quicktree

Re: Hesitation ?? - 02/04/15 10:48 AM

what kind of dist and springs are you using? advance the timing 2* what size squirter is in it now? did you change the front and back squirter? go up one more size.
Posted By: Stroker Scamp

Re: Hesitation ?? - 02/05/15 02:28 AM

Quote:

Where are you at rpm wise when it starts to jump

2k and up
Posted By: Stroker Scamp

Re: Hesitation ?? - 02/05/15 02:30 AM

Quote:

what kind of dist and springs are you using? advance the timing 2* what size squirter is in it now? did you change the front and back squirter? go up one more size.


Stock Mopar Dist.
unsure of springs
went from a 26 to a 31 front only now
Posted By: MR_P_BODY

Re: Hesitation ?? - 02/05/15 04:15 AM

If you pull the dist and add a piece of hose thats
snug on the shaft just a little longer than the space
between the bushing and where the shaft comes through
the dist housing that should take most of the timing
jump out of it.. once you do that and if it corrects
it then use a clamp on sleeve for it(they're cheap)..
might try a bit larger squirter front and rear..
if it gets better try larger... when you went higher
on the base timing did you restrict the max timing..
that takes welding up the slots.. otherwise you will
end up with way too much timing... also.. keep the
vac unplugged at the dist but plug the hose until
you get a handle on this
Posted By: Quicktree

Re: Hesitation ?? - 02/05/15 05:02 AM

Quote:

Quote:

what kind of dist and springs are you using? advance the timing 2* what size squirter is in it now? did you change the front and back squirter? go up one more size.


Stock Mopar Dist.
unsure of springs
went from a 26 to a 31 front only now

square the squirters same front and rear, fix the dist
Posted By: Stroker Scamp

Re: Hesitation ?? - 03/01/15 01:43 AM

Update, got the timing at 18* initial and total at 37* for now
so I went up to bigger squirters and hesitation is almost gone, went to 40 in front and a 35 in
back (didn't like a bigger one in back)
Might try to throw a different cam in and see if it likes that.
Thanks for all the help
Posted By: Quicktree

Re: Hesitation ?? - 03/01/15 01:53 AM

if you get the right cam you may not need such a large squirter. try a brown or blue one
Posted By: Stroker Scamp

Re: Hesitation ?? - 03/01/15 02:56 AM

Quote:

if you get the right cam you may not need such a large squirter. try a brown or blue one


That's what I was thinking, I do have the cam kit
so that will be tomorrow.
I did back the timing down to 35* and it seems to like it

Attached picture 8444251-20150228_154821.jpg
Posted By: Stroker Scamp

Re: Hesitation ?? - 03/01/15 02:58 AM

car

Attached picture 8444254-20150228_154758.jpg
Posted By: Stroker Scamp

Re: Hesitation ?? - 03/01/15 09:21 PM

Quote:

If you pull the dist and add a piece of hose thats
snug on the shaft just a little longer than the space
between the bushing and where the shaft comes through
the dist housing that should take most of the timing
jump out of it.. once you do that and if it corrects
it then use a clamp on sleeve for it(they're cheap)..
might try a bit larger squirter front and rear..
if it gets better try larger... when you went higher
on the base timing did you restrict the max timing..
that takes welding up the slots.. otherwise you will
end up with way too much timing... also.. keep the
vac unplugged at the dist but plug the hose until
you get a handle on this



Put the hose on the distr. shaft
Vacuum advance is plugged
bought a pre set disk from FBO and put that
in the dist. set at 18*
tried a different timing light and the jumping mark has stopped
Now to get the idle and cruise a bit leaner
Posted By: RemCharger

Re: Hesitation ?? - 03/01/15 09:30 PM

Quote:

Quote:

if you get the right cam you may not need such a large squirter. try a brown or blue one


That's what I was thinking, I do have the cam kit
so that will be tomorrow.
I did back the timing down to 35* and it seems to like it

Check your center post in the dist cap(where rotor touches) see if its all goobered up. Or smooth..
I had one that got dimply, changed it and back to normal. something to do with the msd, I'm thinkin.
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