86'Bowtie

ok heres the scenario..basic breakdown:

355
holley 750 dp mechanical secondaries(running a vaccum advanced dizzy)
victor jr intake
performer rpm heads 64cc
and the list goes on..any specifics i can answer

so my car runs way too rich, so rich, its rich at idle, but hesitates when you floor it..idk the car runs great until you floor it.the oil seems to smell of gas and when the car is parked after being driven fills the garage up with a heavy raw gas smell.. where do i start? btw car only pulls 9in of vaccum at idle.. how do you fine tune your holley? i jetted the carb down to 70 primary 79 secondary. changed the pv to 3.5 instead of 6.5..car runs pigrich
i know thats a broad question but im really confused
any help is greatly appreciated

Supervisor42

Cam specs?

86'Bowtie

update..

checked the float levels and in the primary, gas jus poured out when i cracked the sights open..so adjusted the float level and checked the accelerator pump diaphram, all good. accelerator pump arm is @ 0 lash but i still get a hesitation. I ordered a pump cam kit its on its way. i adjusted the idle curb screw to get the motor to idle at around 800 in P and around 650-7 in D. then shut the car off and backed the idle mixture screws out 1 1/2 turns out as a starting point. my car is auto so had a buddy put the car in gear while i got a vaccum reading. the car pulls around 8-8.5in of vaccum in gear. i currently have a 3.5 pv. should i go higher? i turned the screws in now each screw in the 4 corner idle is about 3/4 turns in from bottoming out. car smells better @ idle but at wot its jus not there.. anybody have any input??

86'Bowtie

not to sure but its lopey not a huge cam, but very noticeable idle

Supervisor42

Check where the timing is at idle. BTW the Vic Jr manifold is 3500-8000 RPM range.
This isn't a street manifold.

tricky1

iTrader: (1)

I have a very similar setup. PV is a 4.5 on mine. My 4 corner screws work best a 1/2 turn out. Had an off idle bog that was cured by changing the squirters. Front's a .037 and back's .035. Changed the pump cams. 750 comp series holley had pink pump cams and we got really good results out of the green ones on screw hole 1. Before making these changes the motor would fall flat on it's face going to wot from idle. It still doesn't like to be floored when it's cold but anywhere over 900 rpms and it hooks when you put your foot in it. Works great at the track. Had a 1.60 short time last pass we made.

86'Bowtie

i agree with the victor jr not being a street manifold..good point, im gonna try different squirters and increase the pv one size to a 4.5 pv. pump cam kit is still on the way lol. question tricky1 kinda curious of how that setup ran at the track? best time?

tricky1

iTrader: (1)

Best et to date was 11.81. Ran 11.89 last wednesday night.

86'Bowtie

nice.. thats where i think my setup should run..no track times yet. jus got the pump cams in gonna pop the green one in and start from there. Question, did you swap the rear cam as well? what color/size jus curious? another guy told me to throw in the blue 427 cam..so idk ill try both. thanks for the help

tricky1

iTrader: (1)

I run the green ones front and back and .037 squirters front and back. I told you wrong on the four corner idle screws. checked them today. Backed out between 5/8 and 3/4 of a turn. It was running great but I've some really small crap in one of my metering blocks or something because I'm getting a slight stumble I never had somewhere close to the 50 or 60 foot mark. It doesn't do it ever time. The best times tonight when it didn't do this new screwy thing was 11.98 with a 1.62 short time. That was in the final. Lost with a breakout time of 11.98 on an 11.99 dial in.
Check out the link. I'm in the left lane.

http://imageshack.us/photo/my-images/15/scan0002tt.jpg/

86'Bowtie

Question did you have to upgrade your accelerator pump diapram to a 50cc since you run bigger squirters? My kit only came with one green cam.. hmm not good lol also how are you jetted? Do you think by swapping to 70 primary 79 secondary was a good choice? Stock is 71 80

tricky1

iTrader: (1)

I have 30 cc pumps front and back and the stock jetting that comes on a comp series holley double pumper.

86'Bowtie

good then i wont mess with the diaphrams. found a single green pump cam and ordered it fairly cheap.. primarys seem like the green cam. im gonna upgrade my squirters as well, maybe .35 as a starting point. had a fuel leak set me back a bit. question did you ever adjust the secondary idle screw under the carb? wanna get this carb tuned right, should see the track soon

tricky1

iTrader: (1)

I never had any luck trying to adjust the secondary idle screw. Always made my car run worse so we set it back to where it was originally and left it alone.

travis401

iTrader: (1)

https://www.thirdgen.org/forums/carb...ey-tuning.html

86'Bowtie

Very helpful thread, gives a general rundown on holley tuning..but jus the basics im shooting for fine tuning and have questions the thread dosent answer

travis401

iTrader: (1)

basic tuning and fine tuning with the holley is the same, you just use smaller incriments for the fine tuning. if its running way rich then maybe you need to start back at square 1. you cant fine tune if its not in the ballpark on the basic tune.

86'Bowtie

Update..swapped squiters to .31 primary .35 secondary, left the 3.5pv got a 4.5 on the way. runs real good. Only issue is the rich idle which makes it stinky. I feel like im overlooking something simple .. carb is stock jetted now btw any input?

travis401

iTrader: (1)

rich idle would be mis adjusted idle mixture screws.

tricky1

iTrader: (1)

Idle mixture screws and/or power valve. Mine runs way too rich on a 3.5 and does great on a 4.5. Running a Comp cam with .520 intake and .540 exhaust lifts
adv. duration.
int. 287
exh. 293
Dur. @ .050
in. 236
exh. 242.

My carb is Holley part no. 82751, stock jetting, 4.5 power valve with .037 squirters front and back. Green pump cams front and back. Idle misture screws turned out between 5/8 and 3/4 of a turn. We've ran that combination for almost 3 years. The carb is touchy about the exact amount of turn out on the idle screws. Took a little driving before I got it where it would idle fairly well and not try to foul the plugs. 1/2 turn can make all the difference with mine but the cam doesn't make much vacuum either.

86'Bowtie

Update..rejetted the primary and secondary to 73 & 82, stock setup for my particular carb is 71 & 80 ..made a significant difference on the setup I mentioned

tricky1

iTrader: (1)

We recently changed the PV and thoroughly cleaned out both bowls, metering blocks and all the openings and orifices in the main body. I forgot to look at the jets in the front metering block until we had already reassembled the front part. Checked the back before assmbly and those were 80's. I'm guessing that the fronts were the same as yours. Once all the points races are over here at local track we're going to jet it up 2 sizes and put a 50cc pump and the appropriate pump cam for it on the back half and see if the motor can take it. The jetting will most likely be OK but the 50cc pump might be a bit much for my setup.

86'Bowtie

Tricky1 what rpm does the car idle both in gear and in park? Your carb has 71 primarys ..i think im going to go down to 72 primary and keep the 82 secondary. Got sunday off gonna pop in the 4.5pv and swap jets. 50cc huh? I heard after moving to .37 squiters its good to opt for the next acelerator pump Size

tricky1

iTrader: (1)

When it's warmed up it idles around 800 rpms when in gear. Maybe 900 in nuetral. It doesn't idle very well when it's cold but that's because of the cam I'm running. On the squirter and pump size...it's recommended that if you go to a .040 or larger squirter that you use the 50cc pump as well as the larger screws that hold the squirters down and the other way around as well. But you can go to a .037 without any other changes. Since we're using RHS vortec heads with 170cc runners 50cc back pump and .040 squirter's probably going to be too much fuel for our combination but we're going to give it a shot and see what happens. The worse that can happen is that I have to put it back to the way it is now which is actually pretty good for what I have in it.

86'Bowtie

update..finally got the 4.5 pv installed and replaced the main body to a holley hp main body. stock squiters on the hp main body are .31 both primary and secondary swapped the rear for .35 and increased the rear jets to 83 left the primary jets at 73. car has a noticiable difference but still needs fine tuning..

86'Bowtie

issue..car runs good after hp main body installment. only problem now is when im at a dead stop and go, not flooring it from a dig just at casual throttle it surges then once i hit a certain rpm lk shifting into second its smooth and runs great. could this be a squiter issue? 31p 35s currently or anything else fuel related?

tricky1

iTrader: (1)

What color pump cams are you running? For me, the pink ones caused with the stock squirters caused an off idle bog.

http://www.youtube.com/watch?v=eiRIfcrc2yA

86'Bowtie

Tricky im running green both front and back. when im cruising it gargles really bad and if I let off the gas then accelerate, it falls flat on its face then smoothes itself out.

tricky1

iTrader: (1)

Go back to the 31 & 35 squirters and the original jetting.

86'Bowtie

Went back to original jetting, and went 31/35 on squiters..car does the same thing..no change. Heres my carb setup. 750 holley dp w/ hp mainbody. Original jets, 4.5 pv, green pump cams, idle mixture screws set at 1/2 turn out from bottom. Floats are good. any thoughts?

tricky1

iTrader: (1)

No. Sounded like you almost had it all worked out till you changed over the mainbody. I'm clueless. I hope you get it figured out.

86'Bowtie

Update..tried .35 squiters on both primary and secondary, same issue. Im clueless back to the drawing board..