Idle RPM's

[Grabber70Mach 107]

Working on a 69 Mustang with a stock 302 and auto trans. The 69 Shop manuel I have says that the low idle should be 550rpm's, when I set it at this it is fine until you drive the car. If you make a sharp turn or turn the headlights on it will stall. It does have power steering, any ideals as to what is causing this?

[Grabber70Mach 107]

Working on a 69 Mustang with a stock 302 and auto trans. The 69 Shop manuel I have says that the low idle should be 550rpm's, when I set it at this it is fine until you drive the car. If you make a sharp turn or turn the headlights on it will stall. It does have power steering, any ideals as to what is causing this?

[1BAD351 21]

I had the same problem jsut raise the idle to like 750, fuel and the way even oold engiens are built is different now adays and i think that might have somthing to do with it.

[1BAD351 21]

I had the same problem jsut raise the idle to like 750, fuel and the way even oold engiens are built is different now adays and i think that might have somthing to do with it.

[Grabber70Mach 107]

Ok I'll try that thanks

[Grabber70Mach 107]

Ok I'll try that thanks

[R4K 10]

Yeah, sometimes it's a real juggling trick with an automatic. If you set it too high, you're good while in drive, but in park it'll idle too high and want to diesel on when you shut it down.

[R4K 10]

Yeah, sometimes it's a real juggling trick with an automatic. If you set it too high, you're good while in drive, but in park it'll idle too high and want to diesel on when you shut it down.

[jerry69 10]

Sounds to me its a carburator problem, if you going around turns an it's stalling, sounds like your excellator pump and float might be the problem. When I bought my 69 coupe 2 weeks ago it has an Edelbrock 1406 600cfm and it was gunked up with varnish from old gas and wouldn't hold an idle below 1000 rpms and would stall on turns. I tried to turn set the rpm's down but the car would stall even more and setting the idle up was hard on the automatic transmission... I rebuilt the carburator and then tuned it per Edelbrock specs, and now the car will run fine at the Ford factory settings. You might just pop the top of your carburator off and look inside, if you see any brown junk then a rebuild might be what you need, on mine every little hole was plugged & gummed up.... another problem that hides and acts like a fuel or idle problem is a vacuum leak.

[jerry69 10]

Sounds to me its a carburator problem, if you going around turns an it's stalling, sounds like your excellator pump and float might be the problem. When I bought my 69 coupe 2 weeks ago it has an Edelbrock 1406 600cfm and it was gunked up with varnish from old gas and wouldn't hold an idle below 1000 rpms and would stall on turns. I tried to turn set the rpm's down but the car would stall even more and setting the idle up was hard on the automatic transmission... I rebuilt the carburator and then tuned it per Edelbrock specs, and now the car will run fine at the Ford factory settings. You might just pop the top of your carburator off and look inside, if you see any brown junk then a rebuild might be what you need, on mine every little hole was plugged & gummed up.... another problem that hides and acts like a fuel or idle problem is a vacuum leak.

[Grabber70Mach 107]

Thanks that's the same carb that is on the car that I'm having the problem with.

[Grabber70Mach 107]

Thanks that's the same carb that is on the car that I'm having the problem with.

[R4K 10]

Yeah, check float levels. I should have recognized that. I've heard that Ebrocks almost never come with the floats set properly from the factory.

[R4K 10]

Yeah, check float levels. I should have recognized that. I've heard that Ebrocks almost never come with the floats set properly from the factory.

[jerry69 10]

OK the Edlebrock 1406 is easy to rebuild, I used 2 can of carburator cleaner. If you take off the top of the carburator, you'll see what looks like 2 squirters toward the front and angeled into the 2 ports... Watch out when you remove the 2 or 3 screws to remove it. There is a ball bearing down inside, don't lose it...otherwise it's just taking a part and cleaning, make sure to get a fine wire took into the small holes that are clogged. If you have access to an air compressor that will help blow things out. I used the same gaskets since the carburator was less that 2 years old.

 

Tuning is easy..... your 2 front screws turn each one for maxium RPM's the once you have done that turn each one a 1/4 turn clockwise to lean it perfect. That way you won't be running rich, that's in their manual. Then set your idle.... Also be aware of your altitude, I'm 5000 up so I'm always watching for black spark plugs... if your less than 3000 feet there is no worry and the stock parts inside when you bought it will work fine....

 

Any questions just post, you might try tuning the carburator first if the tuning fails then go ahead and rebuild it.

[jerry69 10]

OK the Edlebrock 1406 is easy to rebuild, I used 2 can of carburator cleaner. If you take off the top of the carburator, you'll see what looks like 2 squirters toward the front and angeled into the 2 ports... Watch out when you remove the 2 or 3 screws to remove it. There is a ball bearing down inside, don't lose it...otherwise it's just taking a part and cleaning, make sure to get a fine wire took into the small holes that are clogged. If you have access to an air compressor that will help blow things out. I used the same gaskets since the carburator was less that 2 years old.

 

Tuning is easy..... your 2 front screws turn each one for maxium RPM's the once you have done that turn each one a 1/4 turn clockwise to lean it perfect. That way you won't be running rich, that's in their manual. Then set your idle.... Also be aware of your altitude, I'm 5000 up so I'm always watching for black spark plugs... if your less than 3000 feet there is no worry and the stock parts inside when you bought it will work fine....

 

Any questions just post, you might try tuning the carburator first if the tuning fails then go ahead and rebuild it.

[bnickel 10,004]

also make sure you're setting the idle rpm with the car in gear, the 550 spec is supposed to be in gear, you might try setting it at 650rpm in gear and see how it does that way before you pull the carb apart as well.

[bnickel 10,004]

also make sure you're setting the idle rpm with the car in gear, the 550 spec is supposed to be in gear, you might try setting it at 650rpm in gear and see how it does that way before you pull the carb apart as well.

[Grabber70Mach 107]

Thanks for all the replies, I will try them and let you know of the progress.

[neverhit 10]

Do you know if the Carter Performance 9506 series 4 bl is similar to the edelbrock you mentioned regarding making it leaner? There are two screws at the base as well. I've been having trouble finding detailed info on this carb. I just got my 69 coupe..

[jerry69 10]

Yes I have a Carter AFB 750 CFM on one of my other cars and it's the same carburetor as the Edelbrocks...

So yes your tuning should be the same as the Edelbrocks.

I found an internet site that has a tips for Carters.

 

http://www.carburetor.ca/carbs/tech/Carter/AFB-AVS-index.html

 

If your carburetor doesn't need rebuilding and your not above 3000 feet in altitude you shouldn't have any problems tuning it..... According to an Edelbrock tech I spoke with if you let a car sit for more than 2 months the gas will start changing and gum up the carburetor so I at least drive all my cars every 2 weeks just to be safe.

[neverhit 10]

Thanks. I didn't think to look at a mopar site for rebuild info. Funny you should mention 3K feet. I am at 3200 feet elevation. I'm going to borrow a vacuum tester to help with the tuning.

[jerry69 10]

You might be OK at 3200 feet. I bought a new Edlebrock 1406, 600 CFM for my 71 Chevelle with a 350 and never had to make any part changes inside the carburetor and seems to lean out just fine....The only problem I had traveling from Prescott Valley, Az. at 5000 feet to Ontario, California last June for a carshow was California's cheap summer gas..ping ping ping.... My 69 Mustang coupe also has the Edlebrock 1406 and I haven't had any issues with it since rebuilding it and running it for the last 2 months since I bought the car. The only adjustment at 3200 might be a slight adjustment for the cooler winter weather.... I think I read it in the Edlebrock carburetor manual.... Let me know how you come out.... Sorry about the Mopar site, (he he he) can't win them all. It was interesting reading about the Ford Carter carburetor and what it's made of...