New to muscle cars need some help!

[87.455]

Ok I'm 24 and have always been around sport compacts..... so I finally decided to ditch the import scene and find out what REAL cars are about. I went out and got myself an 87 Regal with a BBB 455 in it (Have always wanted a G-Body). Car runs and drives good. Has a few flaws. I work in a body shop so were straightening the body up, but I don't have any one to really go to for help with my car on the mechanical end. ( I am mechanically inclined... Have done motor swaps and such) I can pull a carb apart and rebuild and put back together)

With that being said. This motor a 72 455 has the original Q-jet on it 7042244 . It also has had a GM HEI put in it. The guy I got it from says the carb has been rebuilt. When I stand in it It just falls on its face for a couple seconds then takes off, sometimes it will even backfire thru the carb a little when i initially stand in it. This is true off the line or cruising. If I'm cruising and stand in it lets say at about 45 mph @ 2000 rpm it will stay bogged down until it gets to around 3500-4k rpms. I'm assuming its starving for fuel. I was told that I need to run 90octane or better in this car. is that true? I always run 87(NO CASEYS OR MURPHY GAS)

[gbsean]

I am sure someone else will chime in but it could also be getting too much fuel hence the bogging until the higher rpm and welcome

[Yardley]

If the v8Buick site ever comes back up, do a search forQ-jet tuning. There is a vacuum-actuated lock that keeps the top secondary butterflies from opening too soon. Many of us would just remove that lock so they open on demand.

But... there is a tension spring that controls how fast the bottom secondary butterflies open. If it is too loose they just flop open and create a massive bog. Once you get enough RPMs then the engine can handle the amount of fuel being dumped in.

That carb should run fine for you, but unless it was rebuilt by someone who really knows Q-jets they'll just screw it up. Do some searching on Google too, but the hits you get will probably be for the v8Buick board.

[Daves69]

Here is a pretty good write up on how to adjust the air valve. http://www.mako.com.au/buick/html/qjet_tips.htm
Make sure you also check the primary choke pulloff this is on the front of the passenger side of the carb. These are usually bad.

GHP-Q3801-400w.jpg

[rmstg2]

Have you checked the timing? Retarded timing will also cause a backfire through the carb.

Bob H.

[BrunoD]

I would first check if the carburetor accelerator pump is working.BrunoD.

[87.455]

Thanks everyone for the responses. It was a combination of the secondary air valves opening to soon and the choke pull off. The car runs great now. Now I just need to loosen the motor mounts and lift the engine a hair to pull the valve covers and adjust the rockers. Started getting a small chatter.

[John Csordas]

Those rockers are not adjustable.

[87.455]

So what do I need to do to tighten them up?

[John Csordas]

Something has to be worn if you hear ticking. ie rocker arm, bad lifter or worn cam. Are you sure it is not an exhaust leak?

[jaystoy]

I would not stress over a tick. Mine ticks, just the nature of the beast

[techg8]

Glad its running well!

I just wanted to point out that your carb 7042244 is a 350 carb from 1972. A 455 carb from 1972 would be 7042240.

There are differences. The 2240 455 carb would have idle air bypass, and is generally jetted richer than a 350 carb.

I would expect to see 73 jets and 43 or 44 rods in a 455 carb 2240 and I would expect to see 68 jets and 42 or 43 rods in a 350 carb 2244. Also the 455 carb 2240 would have slightly richer secondary rods CT than the 350 2244's CZ secondary rods.

Not trying to sell you one way or the other, just giving you some info. The "right" carb for your 455 is a 7042240

good luck!