ok so i did a 305tbi to 350carb swap in my 91 firebird. when i first fired it up it ran ok but not the best i figured the valve lash was off. so i redid the valve lash 6 times and it runs terible. it was pulling about 19hg on the vaccuum guage now its about 10 and the carb spits fuel out the top if i rev it? im using a 4bolt vortec roller block the 088casting and my original 305 heads "for now" could that be causing a problem? i just really need to get this fixed asap my cars been down for the last 3weeks.

 

anyone??

 

Run the valves again. With the engine at #1 tdc, adjust 1,3,4,8 exhaust and 1,2,5,7 intake. Rotate the engine 1 turn (#6 firing) and set 2,5,6,7, exhaust and 3,4,6,8, intake. To set the valves tighten the nut till the pushrod will not turn by hand, then 1/4 turn past that. Hope this helps.

 

I do mine with the engine running. Yes its messy, but, this is the best way to get it jsut right in my opinion. Do one side at a time and loosen the nut until the lifter starts to tap and then just tighten it down until it stops, then just move on to the next valve. Helps if you have a fan to blow the smoke away.

Are you sure you have the timing set correctly? Sounds like its back firing throught the carb and that could spray fuel out of the top.

 

the valve lash is way too tight so im sure thats why its backfireing open intake valve would put enough force back through the carb to blow the fuel out. as for the timing when the balancer is at 0 on tdc for #1 the roter is pointing at that terminal on the dizzy i dont have a timing light so i just advance it by ear.

 

you may want to try 4 to 6 degrees advance for your base timing. The cheapest light at Oriellys is like 35 dollars.

 

alright i got it running good now instead of loostening till it tapped i thightened it slowley till i heard the engine miss then backed it out seems to have gotten it perfect the valve train is nice and quiet now ran into a new problem though now that the engine is running good i took her out for the weekend and found that she has a tranny leak. i tightened all the pan bolts but cant find the leak tranny fluid was all over the bottem of my car it even got on the cat and the starter still not sure how that happend. its a nice steady drip looks like its comming from the front of the tranny right after driving it.

 

In your first post, you mentioned gas coming out of the carb when you revved it.....is it still doing that or did it stop? I'm guessing you meant it was coming out of a carb vent?? That's usually a sign of an improperly adjusted float or a piece of debris in the needle and seat assembly.

On the trans:
-Check the cooler lines (might have a loose or misaligned flare on the tubing at the trans connection)

-Take the dust shield off (if it's not already off) and make sure the front seal (around the torque converter) is dry.

-Check the seal around the trans dipstick (sometimes the o-ring can get pinched during installation)

-It's possible to get the pan bolts too tight and bend the pan causing leaks

There's so many places for the trans to leak.....if this doesn't help, may have to clean all the fluid from the underneath side of the car and start looking for signs of seepage (Hmmmm, I wonder if that's a real word??)

Later,
Boo

 

well the gas was actually comming out the top of the carb it was because the rockers whir way to tight and alowing pressure back into the manifold i fixed that and as far as the leak goes it was a tranny cooler line wich i tightend and it seemed to help but im still getting some tranny fluid leaking and now my trannys not shifting right it goes all the way up to 2500rpm then kicks really hard.

 

it's probably not shifting right since it's so low on fluid

the leaks there somewhere, anything you disrupt while putting in the new motor?

 

can the engine heat up because of the tranny? every time it gets low on fluid the engine temp spikes normally i can keep it around 180 but when it starts to shift hard ie the fluid goes low it spikes to around 220

 

i took the engine and tranny out together so i disrupted pretty much everything. the only two things it can be is the pan or the cooler lines and im pretty shure its the lines my friend that helped me wouldnt leave his girl friend at home and kept trying to have her help even though she know nothing about cars she is the one that put the lines an pan on and thats where the original leak i found was so im sure its one of those the tranny was fine when it was taken out.

 

I fixed the leak...woot the damage was already done though my tranny shifts kinda hard and doesnt shift quite properly but it will work for the next month or so while im working to get it rebuilt. bullet proof 700r4 and 3000stall converter here i come

 

Good that you found the leak........sux it was too late. I'd rather tear one up on the strip than lose it like that.

Good luck,
Boo.

 

me too but hey it had over 100k on it and im sure with the added torque from the 350 it wouldnt have lasted long anyways. its strange how its shifting though when its cold it wont shift till about 2500rpm then when it warms up it shifts between 1500-1800... i floored it in 4th and it wont downshift. is that possibly a tv problem?

 

You stated that you swapped to a carb, from TBI... and now she's not shifting correctly. Do you have the T.V. cable hooked up properly on the carburetor's linkage, and if so, did you adjust it accordingly?

 

yea its adjusted properly the problem is with the tranny ran it 2qts low from austin all the way to waco then had it overfilled for 2days so im sure i got a leaky seal or something tranny starts to shift semi correct once it heats up.

 

ok trannys running better now shifts when its supposed to and no more leaks. my plan all along was to go with a vortec setup but i didnt have the cash when i swapped the engine so right now i have 305 tbi heads on my 355. i just ordered a set of vortec heads turns out they are 305 vortecs the guy told me thy wher 350's. i know vortecs have like a 58cc chamber will i still be able to run pump gas if i strap those on? any idea on what the compression ratio would be? the pistons are dish im not sure how much but any thoughts?