Carburetor problem?

[Anonymous]

Hey everyone, I'm having some car troubles, and the mechanics around here can't seem to figure out what's going on. I've got a '66 Mustang with a 200 inline 6 motor with an old carburetor on it. I'm not sure the condition of a lot of what's in there since I just bought it a couple months ago. When I first start it up, or when it idles, or goes below about 15 mph, the engine runs really rough/shaky and dies. I can remedy this by shifting into neutral and holding down the gas some at stoplights and signs. It runs fine on the highway though. Also, I've taken it to an exhaust shop a couple times, and the gaskey between the exhaust manifold and exhaust pipe keeps coming loose, getting loud, and sucking power out of the car. Any ideas?

 

[Anonymous]

how would it be coming loose? it should be bolted on there pretty tight. also as for the running rough at low speed... what is your timing at idle?? also check for a vaccum leak and fuel pressure would be another thing to look at.

I have my car set up to run full manifold vaccum for the vaccum advance at idle so I get about 20* advance when stopped, runs really smooth, no problem with detonation

 

[fordconvert]

Welcome to the fourms!

You could have a bunch of problems. There are a ton of threads dealing with this issue. Use the search function at the top of the page and read some of the posts to narrow it down to a few or specific area(s) then we can be more help.

Good luck!

 

[mkgcars]

If it won't run right at low rpm then in addition to carb tuning then also consider if the points are set correctly (check the dwell), but one of the typical problems with these sixes are that the harmonic balancer which has the timing mark on it can slip. When this happens the timing can get set incorrectly and that could cause all kinds of issues.
Search the forums on: timing balancer TDC
Should return a ton of info on how to tell if it's slipped.

If it has slipped you can figure out where the proper TDC is and mark the balancer with some whiteout (etc) and the re-do the timing.

After that it could be bad wires, vacuum leaks, etc etc. But start with the timing/balancer and carb tuning and take it from there.


For the manifold: It may be that it's slightly warped and thats why they aren't getting a good fit when they torque it. They can tend to warp a bit - I think it's typically due to running hot. (If the car is set up to run too lean the outer cylinders can run warmer.) The final solution may be to check if it's surface is flat and have it machined if it isn't (have a machine shop check it for flatness in the first place - unless someone here can give you a typical spec or idea of what's okay or not, I don't think I'd just eye-ball it.) Had this type of issue myself, my dad had gotten one from a yard and had it machined and it worked okay for years.


As you find out info on the idle issue post replys and see what additional advise the guys have.

good luck,
matt

PS: What do you have the base idle at for the car? In drive, with lights and blower on, you want it at 575-600. Don't set it to 575-600 in neutral or in park. In those it would be closer to 650-700.

 

[wallaka]

You might could put some blue loctite on those manifold bolts.

 

[Anonymous]

Wow, thanks guys! It feels like the timing's off to me, but I'm no expert. I'll check that out. And how to adjust my carburetor if it's running too lean/rich. The end of the exhaust pipe has a small chip/crack on the end where it connects to the gasket.

 

[Anonymous]

Also, I don't have a tachometer :/