can anyone check out this thread and maybe point me in the right direction?

https://www.thirdgen.org/forums/carb...wont-idle.html

I figured maybe more people on the drag board might have similar combos and have run into this as well.

The last step I did was to open the secondaries a little from being completely closed and still didn't open them to the slots on the secondary side, but just a turn or two since the primaries were open too far. This caused the motor to want even more primary throttle opening to maintain RPM of 900/1000 in gear, and this has me pulling my hair out. I wish it would idle in gear at whatever RPM and not try to die out on me and have me constantly touching the gas pedal. Should I open the secondaries until the slots form a "square" shape and try that as an approach. So far i've done float check, fuel pressure check, timing checked, etc etc to initially set it up.

 

have you checked your idle/air screws? I know mine didnt have the cork in a few of them and they backed out on me and it wouldnt idle for nothing. Screw them in all the way, then back them out 1 1/2 or 2 turns.

 

they're all around 1.75 turns out.

 

You need a secondary pump cam bracket. Quick Fuel Secondary Pump Cam Brackets: QFT-63-2 - summitracing.com

It will allow you to adjust the position of the secondary throttle blades without taking the carb off. This also affects the rpm difference between Park and drive. If you end up being too rich you may have to drill holes in the throttle blades to compensate. You may also have to experiment with different squirters if you end up with a lean bog after launching, depending on the position of your throttle blades and transistion slots. It takes some time to tune a carb on an engine with a large cam for street driving. Once I got my carb dialed in its been great, very street friendly but it does take some time with trial and error until you get it right.

 

should the seconaries be opened up to form a "Square" shape on the transition slots so i can close the primaries more? right now the primaries are open too far and the secondaries you can't see the slots yet, but i opened them up 1 or 2 turns from being shut.

 

Yes the secondary's should be adjusted to where the shape on the transition slots looks like a square under ideal circumstances. With a large cam like you have you may not be able to get it to run with it adjusted like that especially without drilling the throttle blades or restricting the idle feed in the metering block. Try adjusting it properly for the square look, I've always heard no more than .030" should be exposed. Try it at .030" and restart the car and readjust the primaries and see what happends. If you need too, then go further exposing more of the slot on the secondary until you get it to idle the way you want. After some trial and error you should be able to get it to run well atleast with no sputtering and then you can figure out where to go from there. If you're lucky you're done, if you are way rich at idle you may have to drill the throttle blades or restrict the idle feed in the metering block to lean it out at idle. Just remember to only make one change at a time so you can figure out what changes go in the right or wrong direction. And any little change may affect other settings so always recheck your idle mixture screws and float levels ect..to get accurate results. You probably already checked this but I'll ask..how much vacuum at idle and what power valve are you running? I'm guessing you don't have much vacuum and probably need a 3.5-4.5 power valve.

 

4.5 power valve in there and I already checked that. the only other issue I have is a nosey neighbor who keeps calling the cops on me while tuning my carb during the day, the cops come out and say they don't see an issue with the noise and then leave after BSing for 5 minutes with me or so. I'll order up that secondary part you suggested tomorrow and hopefully it'll be at my local speed shop by saturday, if not monday and go from there.

 

i opened up the secondaries and primaries to the same "Square" shape on the slots, and the motor still won't idle high enough at all to stay running. comp said with 106 LSA on the cam I need 1000-1100 idle rpm speed in gear at a minimum. So should I open the secondaries up further, the primaries further....or???

 

i'm going to try opening the secondaries further with the quick fuel cam bracket that was recommended earlier from jbenge, still not running well enough with enough RPM to stay running just yet. hopefully this will help a little to keep it running to try adjusting the mixture screws some more

 

I would check for vacume leaks first. Then pull the cab apart clean it out and file the main body flat with a file.Clean it again and put it back together you can also drill the throttel blades with a .080 drill bit only the primary side.If you still have proublems I would change the timing curve and give the car more timing at idel speed.

 

You should be able to get the carb tuned enough to get it to idle, makes me wonder if you have a another problem. You may want to try more timing for a better idle as ross suggested. I've actually got my timing locked down at 36 degrees but I've got a digital 6 box that has the timing retard on start up. I would leave the secondary alone for now, and play with the primaries. Open up the primarys until you get a high enough rpm to keep it running. Then adjust your idle mixture screws...if you have them too lean you may not get it to idle at all..so you may have to richen them up to start if you are currently way too lean. One you get it to idle in park put it in gear and see how it reacts. If the rpm's drop too much and it dies you may have to adjust the secondary throttle blades. I would guess you will have to open them up further exposing more of the transition slot..try it and see what happens. If its worse that way just try going the other direction. After each adjustment reset your primaries to get the idle rpm you want, idle mixture screws and double check your float levels. It takes some trial and error to get it right. You should atleast be able to get it driveable by tuning like that. Then you can fine tune it and drill the throttle blades if needed, larger squirters, accelerator pumps ect.

 

motor runs much better after i drilled two holes in the primaries at 1/8" in each throttle plate. next I installed that secondary adjuster too. Still seems to idle kinda funky, and sometimes dies out but runs much much better. RPMs seem to "flare" up a bit, i'm thinking the motor wants even more timing and that's why it'll flash up a bunch and take a few seconds for the RPMs to drop back down. Should I run more than 18 initial and 34 total? perhaps even more initial? I still am running the vacuum can and that adds 13-15 degrees at idle as well, so it's 18 plus 13/15 so 31-ish at idle with vacuum can hooked up.

 

I would try more initial timing and/or different advance springs. You may want to even consider locking the timing down at around 36 degrees that could eliminate a lot of your problems. Depending on which springs you have in your distributer your timing chould be coming in close to your idle speed..causing an inconsistant idle. It may be idling on the edge of where the timing starts...one minute its above idling higher..then maybe slightly lower wanting to die once the springs aren't advancing it. Just someting to check out..I have experienced that in the past. I locked my timing down and never went back..its worked out great for me. If you don't want to lock the timing down just be sure your advance doesn't kick in around the same rpm you are idling at, you will pull your hair out trying to tune it.

If your engine revs but rpm's float down slowly when you let off thats a sure sign of being lean. Try richening up the idle mixture screws another 1/4-1/2 turn when it does this and see if it gets better. It should rev quickly up and down, with no hesitation or floating. If it has a bog or hesitation during initial hard acceleration when driving try some larger squirters.

 

 

how do you lock the timing down in a non-permanent way in case that solution doesn't work? Plugs show the idle circuit to be rich as they're black, so I can't see it being a lean condition--they're pretty black, that's why I drilled out the plates to lean them out a little.

 

Depends on what distributor you're using. In the case of mine, an MSD pro billet, you remove the gear, remove the mechanical advance stuff, turn the shaft 180 to where it locks into a spot and put the gear back on.

 

If you are running vacume adv on the dist un hook it.

 

so don't run a vacuum advance on the distributor at all? Since right now it's still hooked up.

 

Yep I agree, ditch the vacuum advance. Then set up your distributer for 20-22inital and 36 total or just lock it down at 36.

 

Locking the timing will clean up the idle and make the engine much more responsive. The vacuum isn't necessary. In case you're still battling an overly rich idle mixtureat idle, I've sent you a relatively lengthy email containing a diagram and instructions on how to put a band-aid fix on the problem by making the idle feed restrictors "smaller" to lean things out a bit at idle. This coupled with the timing suggestions from jbenge should make that thing really crisp and strong! Only drawback I can forsee is difficult cranking, but U can always install a retard/start box to ease cranking should that become a problem for you.

 

Xpndbl3 you will be best to buy a msd distributor and ditch the hei setup. Then you can get rid of the vacume advance and you can set the dist up the way the motor needs it. I like around 20-22 deg @idle and from 34-40 total I set total up at the track start low and advance timing untill you stop picking up mph and et.

 

jesse....i got your e-mail and i'll read it over when I'm not soo tired.

Ross....I have an aftermarket accel distributor right now on it, wasn't really planning on swapping to a MSD setup since without forced induction I didn't see the benefit of spending $400-500 on a complete setup when most my buddies didn't gain any ET or MPH from the swap. I do have a spring and weight setup so I'm guessing I can swap them out for more initial and just leave the vac. can disconnected. Or is it worthwhile to just sell this dizzy and pickup a MSD?

 

I have not used any of the accel dist. But on a msd dist you can limit your amount of adv thay provide you with different size stops to limit the movement of the weights along with different springs. It makes tunning a little easyer thay also provide a stopthat will lock the dist timing down. Msd also makes a dist that will work with out there box also. And I will agree the box made no diff in my et. But it did seem to clean up my idle some.

 

i'll have to pull out my accel dizzy and see how you can limit timing on it.

 

doesn't seem to be a way to limit my timing curve beyond a lighter spring swap and I really don't want to weld on this brand new accel distributor to lock it out, would I be better off just selling this one and buying a brand new MSD distributor to lock it out? furthermore to see if the idle cleans up is there any drawback to just advancing the distributor how it is now to 34-36 degrees at idle to see if that helps before spending money? I'm sure I can't rev the motor with initial set so high, but at least it might let me guage if that will clean up the idle revving issue right?

 

take some safety wire and wrap the part where the rotor attaches to the other part that the springs hook to...did that make sense?

 

ah you think the safety wire would hold up though it is spinning pretty quick? that would stop the weights from swinging out, maybe i'll try that tonight then.

 

i know it will, my pops had his locked out like that for like 12 years.

 

alright i know what i'm doing tonight then. thanks, now it's off to find some safety wire somewhere--hardware store maybe?

 

yeah, hardware store, parts store, wal-mart...

 

locked out the timing with some zip ties per a post by f-bird'88. Car runs MUCH MUCH better at idle and was able to close the throttle blades by quite a large amount. Finding a happy medium between cold motor and warm motor will probably take a while, but at least today for the first time I was able to idle the motor without 2 footing it in gear at 1000 rpm. It still wants to die out if I drop the rpms anymore than that, and I'd really like to hear the cam cackle at a lower idle, but for now I'm just shocked it idles on its own now. Tried adjusting the mixture screws a little here and there against the vacuum guage, but it stayed at 6" of vacuum off the manifold port but opening the throttle blades caused the vacuum reading to go up so I'm going to have to take a vacuum reading off a different source I think. Shouldn't idle have the highest vacuum reading off the carb port? Or does the throttle have to be opened a certain amount to allow an accurate reading to take place?

 

So whats your combo and do you have any track time?