I'm nearing wit's end with my 1980 truck. Missing/stumbling at idle bad. I've tried multiple carbs and everything I know. I'm thinking the intake manifold has a vacuum leak or maybe timing chain has jump a tooth.

Recently I bought a NOS Holley reman, which is definitely the right 1945 for my truck. When I adjust the curb idle speed on the carb, there is a spot where the motor starts running way worse. The adjustment is not smooth.

Is there anyone on this forum that builds /6s? I am at a point where I am likely going to find a local shop to build a complete motor for me. Basically I have given up and the /6 appeal is waning. After work, I'm spending each evening in the garage getting nowhere.

Do you have a vacuum gauge and timing light?

this article is a simple and helpful start.
http://classicinlines.com/vacuum.asp

_________________
1964 Dart GT

I'm a little hesitant to post this, but: Have a fire bottle handy, put a small amount of fuel in a spray bottle. Idle the engine and spray a bit of fuel on the gasket area. You will hear a change in the idle if you hit a leak.
This is an old school test, and does have it's hazards. I fact I would be extra careful on a slant six, as you will be spraying fuel onto the exhaust manifold as well.

_________________
66 Valiant, 225.
84 Van, 225.
71 Maxi-Van, 318
60 Valiant wagon, 225
87 Maxi-Van, 318 4spd

Yiakes! More like old phool... LOL

Just spray carburetor cleaner around gaskets of intake system. No back flash if it catches a flame, and tis stream is easily controlled and directed.

A warped carburetor base may be hard to find by spray alone as it is too large a leak; remove carb, and put a straight edge on its base in several directions looking for gaps. If power brake equipped check booster for vacuum leak.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

hey thanks for the replies gents

I got a reman brake booster on order.

Yes I have vacuum gauge, timing light, even an old Sears engine analyzer. I've spent many hours playing with the idle and mixture screws and the timing. I called a highly reputable shop today and I am going to drop her off next week and let those guys keep her as long as they need.

I might try the spray bottle check. I hold myself responsible for any advice I may heed.

Edit
I have some carb cleaner on the shelf.

what do you mean by is it NOS?
or remanufactured?

carbs rebuilt by the mass-remanufacturers can be troublesome

and have you set the idle air fuel mix,
adjust for max manifold vacuum,, but remember to bring down the idle speed between changes.

http://forums.holley.com/entry.php?429- ... lley-Carbs

Your vacuum gauge should answer this shouldn't it?

_________________
1964 Dart GT

Reman by Holley
I said NOS because the PN is discontinued

I am getting 17 on the vacuum gauge but it jumps all around because of the missing. Basically this problem is out of my league methinks.

May be missing because of stuck valve, or incorrect valve lash adjustment.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I adjusted the valves live. Took two days to do it. But I have never done that before. Every vehicle of mine before this was done statically. Maybe I screwed them up. Anyway, I'll report back in awhile when I get her from the shop.