wont idle
 

the truck wont idle, its actin like its runnin way too fat, but its a 3310 vacuum secondary 750 and i just put size 77 jets, are those too big?
i dont think they r but i may be wrong.
it just wont idle right though, and its burnin way too rich and i can smell gas in the exhaust
please help

Check the power valve. The jets SHOULD NOT effect on how it idles.If the powervalve is blown,or if it is opening at Idle, it will be 8-10 jet sizes too rich. Also if you have the speed screw turned in far enough to uncover too much of the transfer slot in the base plate,it will pull from the main circuit.
Did you use a new metering block gasket or reuse the old?Is it the correct gasket for that carb? Did you make sure there was no left over gasket stuck to the block?

i just put a new power valve in it, i even called holley to make sure i had the right one, and to make sure i had the right jet sizes, which i do, it is a 3310 750 vac. secondaries, 6.5 power valve, and 74s in the front 77s in the back, 7 psi of fuel press. and have set floats properly, proper gaskets and made sure it was clean
im stumped the only other thing i can figure is ignition, could this be the issue, maybe not gettin enough spark

because today it would idle for like a minute before it would start sputterin and poppin through the exhaust, and smoke too,

Hows your timing?

36 total advance

I had a problem with my Holley and that was that the rear 2 jets were stuck open. It didnt matter what the idle was adjusted to they just Pissed fuel down the carb. That might be something to look at.

BOWHAY, what is your vaccume at idle with the trans in gear? 6.5 is the power valve that comes in them when new, but if you are below that with your vaccume it could be opening up.

Again, the main jets will not make it run rich at an idle if everything is set right...

I WOULD TRY 68 JETS IN THE PRIMARY WITH A 3.5 POWER VALVE, THATS WHAT I RAN ON MY 383 ,, MY BUDDIES 454 RUNS 70 JETS AND RUNS A LITTLE RICH,,,,,OPINION JETS ARE TO BIG.... GOOD LUCK..

Jet size does not effect the idle mixture.

ok so the secondary idea makes sence
well heres what was done before all this stuff happened, i had a 650 on the truck, wanted a 750 and a friend had a main body and base plate from one so i took my blocks and bowls and put them on this 750 body, i took out the flaps to clean them up and when i put them back in there was a visible gap around the secondary flaps, so i think what may be happening is that fuel is just runnin through the secondaries cus the flaps are open a lil bit

and due to the fact that i have a lopey cam could tht make it to where i need a different valve?

I did a quick and easy fix and got an edelbrock and installed it. It was just going on a SBC 400 with mild cam that I just putt around town with so I didnt really need a top of the line carb.

X2. Had this expierence too. Had to measure vac @ idle & figure altitude for mine too. Has anyone mentined floats/level etc...? What about a stuck needle & seat.

?
 

Have you ever CHECKED the Float Levels?
Thats the Only way that Fuel would just be Dumping though the Sec.I would be Willing to Bet the Back Float Level is To High or the Float is Stuck from the Needle and Seat,NOT Seated?
Bet,you take out the Level Set Screw and Gas POURS all over the Place!!!
EDELBROKE-if your going to mess with Junk like that?You would be BETTER Off with a Rotenchester(QUADRAJET)!
Later
G 8)

X2 on the float level...

ALSO it is normal to see some day light sround the throtle blades when you hold it up and lok at them...you need to make sure they are centered good since you had them out.

Yes the camshaft is what will determine the amount of vaccume you have,which will dictate which Powervalve you need....If it is blown or open it will be EXTREMELY rich...

Since you had it apart I am thinking an internal leak or as was mentioned the float level..but if the float level was good before you took it apart,it will be the same since all you did was transfer the bowls from one carb to the next. jmo

Also, can you get a response from the mixture screws? If you turn the screws in and the engine doesn't seem to change,or you can't kill it, then you have too much of the idle transfer slot exposed and are pulling fuel through the main circuit.

floats and needles are fine and no there is no response from the mixture screws

No response from the screws means you are on the main circuit..or there is some kind of leak pulling fuel. If it was running ok but rich I would say you had the speed screw turned in too far exposing the transfer slot..but since you had it apart and it won't idle I'd take it back apart.

Thats what I was trying to tell him. On the Holley I had it didnt matter what you were doing with the idle screws it was still running rich and thats when it was noticed that the rear the secondaries were just pissing fuel down the carb. I think I just couldnt explain it good enough. Thats for explaining it better than I did.

I had one that the accelerator pump cam wasn't adjusted correctly and as the engine shook it was bouncing the pump arm enough to dribble fuel. Too hard to say without being there.

ok so if i were using the wrong power valve and too big jets i kno it would be way rich, but would tht make it smoke? if u stand by the exhaust ur eyes start to water from the gas
also is it at all posible to put the rear blades in the front and fronts in the rear?
just tryin to think of anything

Never even heard of that one before... troubleshooting that one would be like a needle in a haystack senario... did even know it could happen. Have had a carb pull extra fuel through trnasfer slots like Tod was saying... even drilled extra vac holes in secondaries. I swear, every time I think I know the basics about carbs now, something new comes around.

It might smoke if it is getting too much fuel and what you are seeing with the smoke is unburnt fuel. At least that is what I am thinking.

Bowhay the throttle blades have numbers on them ...and unless you have a spread bore carb the front and rear will be the same. Hard to troubleshoot from the internet but you cvould have the wrong gaskets or something causing an internal leak or something...I know Holley rebuild kits will often have several different sets of gaskets and you must match them up with the old ones .....I would put it all back exactly like it was and see if the trouble goes away...then start from there.

ok so i went and got a 3.5 valve and i put some smaller jets in it
gonna see what it does, got my fingers crossed lol

I just noticed you said you put 77 jets in it.. the jet size would have been 72 when that carb came from the factory.

http://www.holley.com/data/TechServi...%20Listing.pdf

ok so i think ive found the problem.....
i put about 6 different powervalves in it....no change, smaller jets...no change, so i pull the plugs, they only have like 100 miles on them and they are all black as heck, a few have wet oil on them, there is a significant miss in the motor now so i think i have blown valve seals
because the oil in my pan is still golden brown and not burnt at all, so i doubt it would be the rings
what do u guys think?
any suggestions are greatly appreciated, i know ive been hard to deal with on here before and im sorry but i really need help

Well how old is the motor? Is it a new one? Is it old with a lot of miles on it? I am pretty sure that worn out rings wont cause the oil to be burnt. I could be wrong tho too. I would say do a compression test in all the cylinders to see if they are all good or not on that. It is somewhere to start and we can go from there.

k compression check showd tht the rings are all good
i figure valve seals are the only other culprate

the motor has about 1200miles on it and about 5 nitrous passes

Bowhay what size engine do you have now? Did the 650 carb work good? If so you have something out of adjustment. Either put the 650 back together or borrow a carb that you know works and try it.

i did, and nothing changed, so thts when i pulled the plugs and found oil

Dont use your weed eater mixed gas in your truck

Did you try a new set of plugs after you fouled them out? Put in new plugs and a good carb that works and see what you get then.

Now I'm not one to poke at folks but dam...:lol:
Bowhay, Dennis, you guys are 2 funny.
Jets stuck wide open....lmfao
:D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D

Cp

i replaced the plugs about 50 miles ago becaue they were fouled out with oil, i just blew it off last time and now they are twice as bad
changin them now would just be a temporary fix

You say oil soaked :?: :?: Not gas :?: :?: I think i would now be looking at valve guides and seal's :!: Guides can cause idle problem's if too loose :!: :!: Have you put a vacum gauge on it yet :?: :?:



''JUST MY TWO CENT'S WORTH''

yes oil
and no i have not but i think itis the valve seals, heads are comin off tomarrow

Probably one of those engines never had the oil changed, pull the valve cover and the entire thing is filled with sludge, once the oil gets to the rockers, it cant drain back to the pan bc everything is blocked.

Ok, let me get this straight, your pulling the heads cause it wont idle, man this is good...lmfao!
Tell me this Bowhay, did it idle ok with the 650? I'm thinking it did.

I think you merfed up something in the making of that mis-matched 750 you dreamed up.

Man before you go yanking heads and all, put a known "good" carb on there first.

I dont doubt you may or may not have a valve guide sealing issue, but seriously, the valve guides would practically have to be non existent to leak enough vacuum past them to not idle.

Just my 2 cents, Cp

I think he is messing with you guys

Probably TXHUNTER or whatever his name is getting even for you dropping that rocker ball into his engine....I bet he stole your valve seals and jets.

http://i237.photobucket.com/albums/f...pimpdaddyl.jpg

prolly more of them rocker balls in the float bowls. :roll: :roll: