wont idle

[bowhay]

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

[Tod74]

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?

[bowhay]

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,

[DirkaDirka]

Hows your timing?

[bowhay]

36 total advance

[DirkaDirka]

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.

[Tod74]

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...

[chevynovaman]

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..

[Tod74]

Jet size does not effect the idle mixture.

[bowhay]

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?

[DirkaDirka]

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.

[Scooterz]

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...

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.

[bbchevy]

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)

[Tod74]

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?

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.

[bowhay]

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

[Tod74]

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.

[DirkaDirka]

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.

[Tod74]

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.

[bowhay]

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

[Scooterz]

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.

[DirkaDirka]

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.

[Tod74]

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.

[bowhay]

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

[Tod74]

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/TechService/Technical/Carb%20Numerical%20Listing.pdf

[bowhay]

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

[DirkaDirka]

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.

[bowhay]

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

[BEAST477]

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?

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.

[bowhay]

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

[kwkracing]

Dont use your weed eater mixed gas in your truck

[BEAST477]

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.

[cepx111]

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

[bowhay]

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

[mopar1968]

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''

[bowhay]

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

[kwkracing]

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.

[cepx111]

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

[kwkracing]

I think he is messing with you guys

[Tod74]

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/ff253/Tod74/bowhaypimpdaddyl.jpg

[MEMRACING62]

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

[bowhay]

no guys im not stupid, i took the 650 off because it wouldnt idle, and i put my buddies 750 tht i know works on and the prollem continued,
i am pulling the heads because the valve seals are blown, and need to be changed
overwise there would be no oil on the plugs no miss and no blueish grey smoke in the exhaust,
im not tryin to be a dick, but i wanted help from you guys, u dont gotta make fun, as easy as it may be to do lol

[bowhay]

and its not idleing because the plugs are fouled from the oil not because of a vaccume leak

[bbchevy]

You DO Realize that You can CHANGE the Seals w/Out Pulling the Heads off!If its a SBC,and the Heads had a O-Ring type of Seal?Go down to the Local Auto/Machine Shop.Tell the Machinist you Need a set of UMBRELLA Seals for a SBC.They can be Changed with a Moroso Valve Spring Tool 1 @ a Time.And thats a hole Lot easier than Pulling the Heads!
Truthfully,I think the Guides would have to be REAL Bad for this Problem to Happen???
Later
G 8)

[THERATTLER]

I have run small blocks with NO valve seals before and never fouled a plug...guides would have to be worn slap out to leak that much oil , I THINK YOUR JETS ARE STUCK OPEN :lol: :lol: :lol: :lol: :lol: :lol: :lol:

[bowhay]

but how else would there be tht much oil on the plugs?
it isnt the rings, cus compression was good on all of the cyllinders

[kwkracing]

ITs probably gas fouled plugs, not oil

[mopar1968]

Could be his Bellhousing gasket blown out :!: :!:




''JUST MY TWO CENT'S WORTH''

[bbchevy]

I would Also say that its Gas Not Oil?
Let me step out on a Limb and ask?What do you have for IGNITION?
Later
G 8)

[Scooterz]

SLOW DOWN!!! this is giving me a headache... I can't believe this thread is still going.

Bowhay: I am not the smartest guy on carbs either, but slow down & lets go back to the basics. I agree- valve seals are not why this thing has no/poor idle & is rich.

1. What the is the vacuum read at idle around 2K RPM???
2. Your jets appear to be too big like Tod said.
3. Is the carb too big for the application???
4. Flip the carb over & notice the adjustment for the secondary butterflies... where is it set??? You can over adjust this & cause more problems. have you messed with it?
5. WHERE are the floats set??? primary & secondary??? You said they were "fine"... what is fine to you??
6. Like Tod said, your cam spec will cause a certain amount of vacuum (or lack thereof) at low speed/idle. If you do not have a lot of vacuum at idle, you may be dumping fuel & not enough vacuum to compensate for it. This is why some folks will drill little holes in the secondary butterflies.
7. Are there any other vacuum sources on the motor (P/B Booster) etc...??
8. What distributor? does it have a vacuum advance? Manual? If vac advance, is it the low vac style?
9. Low vac will also dictate which PV you should use as well.... it has to have enough vacuum to open. To determine this, get a vac gauge reading. Randomly changing PV's will cause more confusion.

Lets get all the facts straight. One adjustment at a time without tearing apart everything... note the adjustment/improvement. Once all these facts are answered we can help you better. Scoot

[BEAST477]

Have you ever used nitrous on this engine?

[bowhay]

ok yes i have sprayed it 5 or 6 times
i am fairly positive it is not a carb issue because it began with the 650 i had and got worse with the other, i also put a buddies 750 on it tht i know works with no luck, it IS oil on the plugs, if it looks like oil, and smells like oil it must be oil
i was recently told tht when i built this motor i did a big no no and reused the seals because i used the same headsafter they had been vatted
this is why i am leanin toward them as the prollem and because the plugs have fouled out 3 times in 1000 miles, the oil is all the way up on the threads of the plugs not just the tips
there are only two ways to get oil on the plugs right? rings or valve seals
i do not have a vaccume guage but it would do no good due to the fact tht it will not idle or run

and ya mopar lol ive had to change those a time or too jk :P

[bowhay]

and its a malory unilite dist. with a msd coil

[THERATTLER]

if you are getting enough oil down valve stems to foul the plugs then the guides are worn out bad.,,as I stated earlier , i have run heads with NO seals at all with no problems ( good tight guides) just my input :)

[dragonmaster093]

heres a thought i know my cam is way to big my carb way to small and my preformer intake to restrictive for my heads (ported and polished) and my car idles like crap when it does made small adjustments to carb and got it as best as i can. (found out recently the parts arent meshing) so my thoughts on this are that one ore more parts not meeting the requirements you need. and the 750 you borrowed may not be adjusted to your engines need hence the problem still there

[Tod74]

Do you have a PCV valve? Do the valve covers have baffles? High volume oil pump?

Did you steal gas from your father's shed...possibly his weed eater gas? :)

[mopar1968]

How much nitrous are you spraying :?: And how much timing were you using :?: I just got a feeling this might be the root cause, When i ran nitrous i was tempted to use it when i shouldn't :!: :!: When you used it, did the engine make any noise at all :?:



''JUST MY TWO CENT'S WORTH''

[cepx111]

After reading thru the carnage once more, I'm starting to think you may have toasted the rings and or pistons with the "squeeze" there BOWHAY.

It's not hard to do, add a little too much nitrous, not enough fuel, too much timing, and wham-bam thank you mamme>>>Smoked another SBC!!

Again, Just my 2 cents...

[zipper06]

First time weighing in on this thread, i can say if it's oil, the rings or the guides have gone south. I don't run seals an any of my racing engines, but they are on alcohol, on my street engines i only run ford bonnets on the intakes. I donot run more than .002 clearances on the guides, any more than that i knurl them or replace them.

JMO

Zip.

[THERATTLER]

I would like to have all the engines ole bowhay has trashed in the last year :D

[bowhay]

u would only get one
like i said i did a compression chekc and the rings are fine
and i sprayed 125 with 32 degrees and 110 octane
ran fine and sounded fine no wierd noise

[mopar1968]

What was the compression reading on each cylinder :?: :?:




''JUST MY TWO CENT'S WORTH''

[THERATTLER]

I had an intake gasket blown between the port and lifter valley and had similar problems , idle problems and oil in cylinder , might give that a check...same engine backfired one time and blew one valve cover up like a football :lol:

[bowhay]

they were all about a 170 lbs

[DirkaDirka]

Does it have aluminum heads on it? Did it over heat at any time??

I had a 89 Probe that warped the head when it overheated one time and it wouldnt idle at all. Found out I burnt the rings in it and warped the head. There was no water in the oil or anything.

[Tod74]

Bowhay do you know anyone who could help you do a leak down test? That will give you a better picture of the condition of things.

[bowhay]

ok so i found the culprate
i pulled the heads and there was a puddle of oil standing on top of number 7 and 4 and a lil on almost all of the valves, so i pull the springs off and the guides are so bad tht almost all of the valves have play in them
and a few will actually jiggle from side to side,

[THERATTLER]

if you are getting enough oil down valve stems to foul the plugs then the guides are worn out bad.,,as I stated earlier , i have run heads with NO seals at all with no problems ( good tight guides) just my input :)
:D :D :D :D :D :D :D :D :D

[dragonmaster093]

nice job manic

[TheYellaBrick]

5 pages to figger this out ????????? :shock: :shock: :shock: :roll: :roll:

[lively]

nice job manic

MAN--NOW HE WILL HAVE A BIG HEAD AND WON'T SPEAK TO US SMALL PEOPLE :oops: :oops: :oops: :oops:

[THERATTLER]

it already outgrew my hair

[dragonmaster093]

let me fix this mopar and others who said this nice job :lol: :lol:

[kwkracing]

most guides have a few thousands of play unless the heads are new or near new or have had the guides replaced. Find someone to help u go threw a entire engine.

[bowhay]

im going to go threw the whole thing
i know there should be some play but there is ALOT in a couple of these guides,
im takin the heads to the machine shop tommarrow to get new giudes installed and another valve job done

thanx so much to yall who helped me figure this thing out

[THERATTLER]

dont take it to the same one that did those heads

[kwkracing]

dont take it to the same one that did those heads

:shock: :shock: :shock: :shock: :shock:

[bowhay]

im not

[Tod74]

You said this engine had 1200 miles on it...and you say ANOTHER valve job,so I assume you had the valves ground when you built the engine...How did they not know the guides were bad ?Hard to imagine any competant machine shop doing a valve job on a set of heads with worn out guides.

[cepx111]

If you got oil puddled up on top of the pistons, you've got other things to worry about than a wiggle in the valve guides.

JMO>Cp

[MEMRACING62]

If you got oil puddled up on top of the pistons, you've got other things to worry about than a wiggle in the valve guides.

JMO>Cpthats for sure!!

[Scooterz]

Well Bowhay- I guess you don't need to worry about getting a vacuum reading on the car-bee-rater... at least you have some extra power valves now. LOL!!!

[MEMRACING62]

BOWHAY, NO MORE DRINKIN BEER & HOT WOMEN IN THE SHOP WHEN ENGINES ARE BEING BUILT! :P

[bowhay]

aww man thts the best part :P
and what other things should i be worrying about?

[Tod74]

BOWHAY, NO MORE HOT WOMEN IN THE SHOP WHEN ENGINES ARE BEING BUILT! :P

http://i237.photobucket.com/albums/ff253/Tod74/bowhaypimpdaddyl.jpg

He can't help it....

[cepx111]

aww man thts the best part :P
and what other things should i be worrying about?


Yeah it is...lol But still no matter how tempoting it is, save the beer/hot women till after the work is done :lol:

Other things? Well I'd start by pulling the pistons.

Broke rings, seized rings, collasped rings glands, cracked pistons all come to mind.

That or you've got standard pistons in a .060 over hole.

That amount of oil has to be coming from the bottom end.

Goodluck & tell us what you find> Cp

[bowhay]

il be sure to let yall kno what i find
thanx again for the help and suggestions

[mopar1968]

Well is the engine going to live or not :?: I have a great small block MOPAR engine i will sell you it loves nitrous, I ran a 200 shot on it, just check my profile and look at albums,let me know and i will make you a killer deal :!: :!:


''JUST MY TWO CENT'S WORTH''

[MEMRACING62]

the mopar engine will make the chevy truck sick :cry: it will throw up the mopar motor all over the drive way and give it a bad rash!! :P

[mopar1968]

Shoot it will make it into a wild stallion, He won't be able to harness all that power, But wait on second thought he isn't use to that kind of power he drives a Chebbie :!: :lol: :lol:


''JUST MY TWO CENT'S WORTH''

[eerode]

im stumped the only other thing i can figure is ignition, could this be the issue, maybe not gettin enough spark

[eerode]

It didnt matter what the idle was adjusted to they just Speed Test (https://testmyspeed.onl/) Pissed fuel down the carb. That might be something to look at.

[aquilesopkarg]

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 Speed Test (https://testmyspeed.onl/) and i can smell gas in the exhaust
please help
Is it the correct gasket for that carb? Did you make sure there was no left over gasket stuck to the block?