help setting up carb....???

[Psychopete]

Keep playing with the timing to see if it improves, but still think it's your accel pump cam:

 

[ford1386]

Motor has a brand new double roller chain in it...

 

[ford1386]

If I advance timing ahead 5 degrees stumble is better but it could just be because rpm are up more and it seems to backfire through carb more with 35 nozzle in it, did I go the wrong way on the discharge nozzle maybe I should go from holley factory #31 to a #28

 

[ford1386]

Hole 2 on orange pump cam didn't seem to help, but I did notice if I tighten up accelerator pump linkage spring hesitation seems to lessen

 

[kimcrwbr1]

Where does the timing go to at about 3500 rpm and does it ping when you put it under a load.

 

[kimcrwbr1]

I had a 79 dodge van with a 360 in it that never run good with factory spec even after a timing chain set. I had to time it by feel and mpg. If I could get it to ping twice lightly at 35mph to the floor I would get the best mileage and power. The engine was still running good when the rest of it was falling apart at about 350,000. The only thing I dont have any exp with msd ignition or know how they retard the timing under a load except spring pressure. It seems to me they are more for high performance and not DD. I will keep watching this thread be sure and post what your solution is you will figure it out. GL If you can get your hands on a tailpipe sniffer that might help you dial it in.

 

[Beanmachine7000]

*cough* EFI *cough*

 

[ford1386]

im not sure where the timing is at 3500 rpm never checked it but i will. no it doesnt ping when under load. and i dont have access to a tailpipe sniffer or no where to get one...........EFI is expensive too, but your right prolly wouldnt be having these problems.

but whats to say that the harmonic balancer isnt messed up maybe the outer ring spun on the rubber or something, after all i did reuse the factory balancer instead of buying a new one..............

 

[kimcrwbr1]

When pony carbs builds a carb in there instructions they tell you to take it to where it pings and back off a little till it dont but that is with a vacuum advance and when you lose vacuum it retards up to 10 degrees with WOT I dont know how the MSD knows when to retard the timing other than rpm and spring pressure get it to advance and retard in relation to engine speed,a nice smooth advance up to WOT. As the engine idles higher when you advance it can you drop the idle or does the butterfly close all the way you should have better control with the idle air also. Wish I was there to beat my head on the bumper with you.

 

[ford1386]

As the engine idles higher I can turn the idle screw back, but then I have my hesitation again I only have the hesitation at lower rpm I'm gonna say less than 2000 rpm so the closer it idles to that the less hesitation I get, but if I put it at full advance it has no hesitation in the driveway but never drove it on full advance...

 

[kimcrwbr1]

http://www.setyourtiming.com/ found this hope it helps

 

[kimcrwbr1]

Is that the same dizzy you have.

 

[ford1386]

Yea the msd pro billet

 

[kimcrwbr1]

figure out the total advance and the curve from low to high maybe get a new damper so you have an accurate mark for top dead center. the carb dont affect the timing but the timing affects the carb the electronic advance upgrade gives you control of both the curve and total advance otherwise you need to play with springs and stops.Do you have a special cam or any upgrades all affect the timing get it right then you can dial in the carb properly. From what I have read and seen the advance should stop around 35-40 grand and rise steady in relation to rpm ? how is your off idle hesatation in relation to timing. Try the heavier springs in the dizzy advance it till it pings under aload and back off till it dont ping then adjust the idle air screws for the highest vacuum or rpm you can get and check they are even within 1/2 a turn. Keep backing off the idle stop to 800 rpm and adjust the idle air needles a few times till it dont move unless you turn them in lean.

 

[ford1386]

I tried advancing the timing ahead a few more degrees to see how far my balancer may be off. im around 20-21 degrees and it pings but i dont notice any hesitation but it has no top end power at all, it just revs up. So im gonna try and back it off a little and see what happens then i will mess with advance springs and stop bushings and idle air screws