442fanatic

Hey Guys

Slowly getting my car's kinks worked out. After replacing the intake gasket with a Joe Mondello 3 piece intake kit.

We have found I may have carb issues.

It was overhauled sometime ago, after engine was assembled... But not tuned on engine by the guy. It was put on the engine, car went to body shop. 2 years late we are tuning and working on kinks. yeah should of been done before body shop...
The main throttle shaft has had new bushings put in.

The symptoms: won't idle well, at 750/800 rpm will keep running. Once at operating temperature it pings accelerating after 1700 rpm.

I am using 91 octane fuel. Mechanic (who is good) timed the engine and has it on I have been told.

He has told me the base plate of the carb could be cracked around the idle air jets, causing the idle issues. Pinging he says could be because the jet in the carb is two small.

The number off this quardrajet is a 7042251. It is on my olds 455, which this carb came with. After some research online it is from a 1972 olds 455 or 350. 4MC carb

Engine has higher compression pistons figure 9 or 9.5 to 1. Blue vood lunati cam with I have the cam specs here not sure which ya need. It isn't a radical cam. More so than stock..

Have another shop that does work on older cars as well, said he could re jet the carb. Also he doesn't think the base plate is cracked. I have priced a "reman one" through Iowa Auto a former AC Delco store for $270. But have heard people get burnt on buying "reman" carbs. Not a bad price, and the shop could get to that quick perhaps in their labor.

Pros though if I went to the shop, he can go through overhaul, correct if possible, or say replace... but tune it...

Not really wanting to go to a Holley or Edlebrock. Did that once with an edlebrock, they don't like stock intakes with the exhaust cross over...

Ideas? Personal opinions? I know I may have opened up a cup of worms.
I am looking for what people have done in a similiar situation themselves. I know there are some crack Olds mechanic guys I would to hear from on here.

olds 307 and 403

It probably needs more fuel at idle and rejetting as well. I would send it to Ken at Everyday Performance. He only charged me $250 to recalibrate my carb and that included bushing work. I am betting you need an adjustable vacuum advance canister, stock ones put out a lot of extra timing.

442fanatic

Thank you, will contact Ken. Checking out local guys too, if any, who have good experience with them.
Just don't want to have a shop run up labor to about the same as a reman carb, then tell me to get a reman carb...

Fun71

So what are the timing parameters? Initial setting, total advance, and how much vacuum advance?

What temperature is "operating temperature"?

And what type of distributor - points or HEI?

Octania

It sounds like an HEI conversion that was not tuned to the engine. Such as, the limited vacuum and mech. adance kits.

Gary M

I had a mild cam, ported and blended heads, under 9 compression. After a few carbs that always idled alike ( had a post on it) I had a shop drill out the idle circuit a little at at time till it idled smooth. The cam, compression, porting/ blending apparently caused a need for more gas at idle than stock. This drilling reinstall - repeat did cost me 400.00 due to per hour charge but after buying multiple carbs that all acted the same I realized modification was the only route. The pinging is another issue. Mine was caused by improper timing.