ok i was looking at my motor today 305, rochester e4me 4bbl carb, i pulled the throttle till the 4bbl opened, and it looks as if it shot a little fuel on top of the secondary plate, is that normal?, so i pulled the throttle again and pop, flame outta the 4bbl then went away, what could be causing this?

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86 Camaro with 88 305 LB9 using 86 carb setup, edelbrock performer manifold, 305 S/R Torquer Heads, Hedman Headers, Crane Compucam 2032 edelbrock cat-back, gutted cat, slp underdrive pulley, mallory ignition, 305 h.o dual snorkel air cleaner, hypertech thermomaster chip,160 degree thermostat, 5-speed, 3.23 posi

95 Beretta Z26, 3100 V6, 4 Speed auto, stock

 

I assume both the conditions described are with the engine running.

Do you have a bog or stumble when you floor it when driving? Have you adjusted the AV spring tension? Is the rod still there between the choke pull-off and the AV?

It sounds like the secondary air valve is opening too quickly. If it isn't a problem when driving, it isn't a problem.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 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/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. 0.030 over 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlock header mufflers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1/94.6 @ 5800' Bandimere.

 

Quickest thing that comes to mind is the timing, and if you just set it then make sure you rehooked up the wire for the timing.



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1987 Firebird Formula
305 LG-4
Crane CompuCam 2030
700-R4 Trans
4 barrel quadrajunk remained by holley (this carb stinks!!!)
edelbrock performer intake
Hypertech Thermomaster Chip
Open Element Air Filter
No Cat with Straight pipe (Dynomax muffler rusted apart and fell off probably could not stand the heat )
Accel H/P Coil

- Soon to be installed
Holly Spreadbore 600
Edelbrock TES
True Dual exhaust or 4 inch single pipe to dual 2 1/4"
1.6:1 Ratio Rockers
Set of New Valve Springs

 

Once the secondary throttle plates open fuel sprays around all over the place on the secondary side of the carb. So, that's normal.

Fire is NOT normal.

I agree, check the timing. Severely retarded timing can cause backfires through the carb, and possible small fires.


[This message has been edited by Damon (edited May 18, 2001).]

 

Timing will cause it and one other thing but for the life of me I can't remember. Go get a Haynes manual on q-jets or rochesters. I think it might be float adjustment or something. Or you might just wanna replace the carb if you set-up the timing right.

 

well the carb has already been replaced TWICE, it was working fine before, i upgraded to world product s/r torquer heads and a crane compucam 2032, i set the timing to the stock setting a while ago but it didnt have no power, and if i remember right it didnt backfire through the carb, would the valve lash setting cause this?

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86 Camaro with 88 305 LB9 using 86 carb setup, edelbrock performer manifold, 305 S/R Torquer Heads, Hedman Headers, Crane Compucam 2032 edelbrock cat-back, gutted cat, slp underdrive pulley, mallory ignition, 305 h.o dual snorkel air cleaner, hypertech thermomaster chip,160 degree thermostat, 5-speed, 3.23 posi

95 Beretta Z26, 3100 V6, 4 Speed auto, stock

 

Does it fire right up when you start it?

If no, set the timing right and make sure the distributor isn't a tooth or two off. You can probly more advanced then the 'stock' setting. I run 8-12 intial, 24 centrifugal (distributor weights) and about 10-15 on the can, but I don't run n2o either.

Since it's a new carb have you tuned it in or made the proper settings on choke etc? If not then do that or take it to a good carb shop that will guarentee their work.