1986 Pontiac TA 305 carbuerated.
I have a question. My car has hesitation at the begining of most take offs and I can't figure out what the hell is causing it. I put in a new EGR valve,checked all vacumm hoses, changed carb. gasket,plug wires,cap,rotor,distrib,timing,plugs,carb has a rebuilt kit in it I think and I asked around and everyone seems to tell me its a vacumm leak. I ran out of gas once which I think might caused the fuel pump to go bad but it works fine at high rpm's and it did it before I ran out of gas so I'm just eliminating all that could cause this hesitaion. I would really appreciate it because im losing my mind trying to figure out this problem. Any comments or suggestions would really help.

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1986 Pontiac TA 305 carbuerated.

 

did you put a new or used carb on it? how does it idle?

 

I didnt change the carb. so its the same carb that came with the motor. It idles a little off and is sometimes hard to start. I guess its been a while since we had the timing checked but still when i had it checked it still had the hesistation. Would off timing do it? I also wanted to know if an open element air cleaner would need the timing to be set higher? I've heard that it needs a slight higher adjustment if someone is using an open element air cleaner. Is that true? Any comments or suggestions would help.

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1986 Pontiac TA 305 carbuerated.

 

It's your open element air cleaner. The stock unit has a divertor valve in the snorkel that maintains the air temperature going into the carb at about 110 degrees. With the open element, it's just gulping in air at whatever the under-hood temp is. What you are describing is the classic q-jet symptom of not having that heated air going into the carb.

Advancing the timing slightly will help: last summer I was going to the track on Fridays and used an open element. I didn't have the hesitation problem when driving it around during the week after I advanced the timing (I went from 0 to 6 degrees, but that required mid-grade to suppress pinging). For the winter, I have the stock cleaner back on and the timing back to 3 degrees.

On the old mechanical q-jets, you could adjust the main metering rod depth to eliminate this problem. I haven't figured out yet how to do it with the computer controlled version, but I'm sure it can be done.

The other route is to go dual-snorkel to get the air flow an open element can give (or at least a lot better than the single snorkel), and also gives the heated air the carb likes.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/LB9 block, ZZ3 cam and intake, WP 305 heads ported & polished, Hooker headers & y-pipe, hi-flow cat).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

Could I just remove the divertor valve from the stock air cleaner assem. and just lay it to the side with it hooked up to the carb.? Would it still function correctly? Any comments or suggestions would help with using an open air cleaner on a 1986 Pontiac carbuerated TA. What do I have to do to solve hesitation?


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1986 Pontiac TA 305 carbuerated.

 

Also what is involved in making a dual snorkal? and what do I need? I've seen them before but never thought it would be worth making one. Thanks

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1986 Pontiac TA 305 carbuerated.

 

You really need the closed housing of a factory air cleaner for the divertor valve to work properly.

Check the tech articles on making a dual-snorkel air cleaner. They're also availalbe new (many $'s).

Like I said, I don't yet know how to adjust the CC carb to eliminate this problem with an open element. Perhaps Ed Maher or others from the carb board could jump in. But, like I also said, advancing the timing will help. How much it takes to eliminate the hesitation completely is the rub.

 

alright cool maybe ill make one of those. Thanks for the help bud.