I have a 85 GLS wit a 12A bridgeport. When i take it off it sounds like its misfiring or splutters. It does it around 3k RPMS and feels like it gets worse as i go higher in the RPM range. It also it in 2nd and while cruising u can feel it hesiate for like a millisec. Like its running lean for that second or misfire.

I changed, cap, rotor, wires (NGK), and plugs (NGK).

Its a BP, a holley carb, (dont kno which one, beleive its lower than 700 somethng?), racing beat intake manifold, and header. Holey Fuel pump running at 7 P.S.I.

Can anyone help please?

 

anybody?

 

This may not help, but are you sure your leading and trailing wires are hooked up correctly? The ones from the coils to the distributor.

My car is stock, but it exhibited those same mannerisms when my friend put them on backwards.

 

id try upgrading your ignition system...maybe trying a second gen direct fire system, msd, or DLIDFIS. it sounds to me like you are having ignition problems or are running a bit rich...id try turning down your psi to about 6psi and start from there.

 

What muffler are you running? The RB? I have a friend who runs a BP, he had to dump his RB muffler because of exactly the same symptoms that you have.

 

i do have msds...i had it running at 6 P.S.I and it was doing the same thing.
yea it does have RB muffler. wires are hooked up correctly

It doesnt smoke much. only on start up and when i rev it high but at idle no smoke just smell of rich fumes.

 

are you running full MSD ignition or just coils? I decided to run Crane ignition due to the tunability at the boxes, instead of the replaceable rpm modules on the MSDs. Several of my friends mentioned the same thing with the MSDs that I had to do with my Cranes, when remoiving the ignitors. Have to check when I get home from work but I remember having to hook the wires up backwards from what they list to work (this is just for the rotary, Crane also offers no tech support for rotary ignition so I had to figure all this out myself). If you are just running MSD coils, try cutting back to 6psi on the fuel. If you are running a 700cfm or slightly smaller carb on your 12A bridge, I would think that is a bit too much carb. Even RB only uses the 650 Holley for the 13B bridge, which is what I'm running. I was trying to run a Holley Street Avenger 770 at first. It seems like I tried at least 900 jetting combos and never got my 13B bridge to run well. Bought the new 650 from RB, and all I can say is a HUGE improvement/increase in power. Not to mention trouble free. Bolted it on and haven't had to adjust it yet, except for the idle, slightly. You may have play with your jetting to not dump so much fuel in there. Also what regulator are you running?

 

i have a full MSD ign with rev limiters. im using a holley fuel pump and regulator.

 

does it revs but lags for a few seconds, then continues to rev again?

 

Not that this is causing your misfires, but if you are running the stock fuel lines to the carb and returns to the tank, just with a Holley blue pump, I would strongly suggest a change asap. A big Holley mixed with bridge-porting will starve the the bowls while under hard acceleration = lean conditions, then = new 12A. From re-reading your initial post, I'm leaning towards your fuel delivery, specifically in the carb jetting. Find out exactly what carb you are running and let us know.

 

It sounds like carb issues to me. If the carb was not one modified by RB you might need to add an open air spacer on there. Holley designed the carb to have a constant pull working on all 4 barrels, and if its a non modified crab atached to a RB manifold this could be your problem. A simple fix is one of those open air sapcers between the carb and manifold.

 

they told me its a 600 holley. ima try to take a pic later of the setup.

 

600 sounds about right for the 12A bridge. Just depends, like Hyper mentioned, if it's a RB modified or out of the box Holley. I tried and tried to run a 770 Street Avenger on my 13B bridge with a 7" Camden SC and couldn't get it to work. I bet I tried, at least, 9,362 sets of jets in there and never could get the thing dialed in. Dropped the $650 on the RB 650 for the 13B bridge, installed it, and the 13B runs flawlessly now. The only adjustment that I have made since the install was a 1/4 turn for just a grunt more idle, and that was the day I installed it. Words cannot describe how the RB carbs perform.

 

it seems like it runs fine when i floor it to get some power..but like driving normally or taking off it splutters and i gotta get out of first gear quick (around 2,500- 3,000 RPMS) to stop the splutter.