Yoruai

67 coupe
4bbl 289


I just put on a new intake manifold and got the car runing after sitting about a year. It's not timed perfectly as I don't have the tools to do so but it runs at idle without a hiccup. The problem is that the gas pedal seems a bit over responive. Give it just a little press and it sounds like it's reving up to 3000 (no tach). Any thing more than that little press and the engine shudders and dies.

Oh yea! The carb is an Edelbrock performer. When not running it squirts fuel all the way up on the raised hood. At idle itdoesnt appear to do this however. I've only gotthe fuel opend a turn and a half, the air isonly a half turn more.I'm at a loss, is there a carb problem here?

OhioMachIRunner69

As long as you have the idle set where you want it the rest of the rpm range should be fine...if you installed a performance intake manifold it will flow better than the stock one giving the engine the ability to rev more freely. It may only be that the acceleration is different than before that it seems to be wrong.

First, I would set the carb back to factory specs ( I belive that the idle screws should be at 2 1/2 turns on a Performer carb but double check your manual) and try to get the timing dialed in more accurately. You can adjust the timing by listening to the engine when you turn the dizzy. Turn the dizzy to the right to advance the timing till the engine starts to stumble. At that point turn it back till it goes back to normal, and then a few degrees more. Turn the car off and try to start it again. If it starts hard your timing is too advanced, so turnit a few more degrees to the left...stop the engine again and try to restart it. Do this process till it start easily and you will be fairly close to the correct timing.

With all thing equal now you can see how it acts. What # carb do you have? Edlebrock Performer carbs with electric chokes are tuned to run leaner than their manual choke counterparts, which will affect performance.

The way you described the motor stumbling sounded like the choke was staying engaged. Like I said, get the thing back to square one and go from there, then let us know what you come up with.

Yoruai

I believe it's an edelbrock part# 1805. Not sure as I got it second hand. I was told it is 650 cfm and it has an electric choke. I"ll look more closely at the choke when I try it again. Just came back from attempting to bleed my breaks. Tube attachments on the Innova hand vacuum pump broke.Don't buy one of them.

Yoruai

Thanks to your advice the car is running better now but the idle still seems too high to me. I've backed off the idle screw to where there is just enough fuel allowed to start her without useing the gas pedal. Once she's runing I can back off the idle screw a bit more to make it idle better but would then have to turn it back to start up the next time.

Also the carb sounds like it's sucking in a lot of air. I mean a lot! I have both the fuel and air in as far as they can go on the carb. I thought that odd consideringit ran with them a few turns out before.

htwheelz67

I'd check the acc pump adjustment, too rich or too lean can cause the same problem, go to the edelbrock site and download the tuning guide for your carb, the 1806 is the thunder 650 avs, if its a stock 289 with a stock intake it maybe a bit much.......

falconfixer

Sounds like a vacuum leak to me. When warm/running - spray carb cleaner around the intake connections and then to the carb base (working bottom to top) and listen for a change in idle.

mustangmatt63

It sounds to me like you have a serious vacuum leak.I would check for that before going any further!!Recheck all your intake and carb bolts to make sure they are tight and set the carb back to fac specs and go from there![8D]

Yoruai

I went all over with carb spray and found no leak. The great sucking sound stayed consistant. I did find that my PCV valve is a pretty loose but don't think that would cause noise. I was able to diminish it and get the idle lower by disconnecting the vacuum advance however.

I read a nice carb tuning guide on another forum where the Mopar enthusiest used only a vacuum (gage no tach) to set an edelbrock carb. In the post he also mentioned that it was idiotic to have the vacuum advance pluged into the carb. What's up with that and where else would I put it? Some adapted nipple on the manifold?

falconfixer

He is right - use manifold absolute vacuum for setting idle.