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Spit/sputter/skip and running rough only in gear
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Author:  that4wdwagon [ Tue Apr 14, 2015 2:08 pm ]
Post subject:  Spit/sputter/skip and running rough only in gear
I traded a car for a 1982 Dodge D-150 with the granny 4-speed and slant 6 last weekend and had to drive it about an hour back to my house. Let's just say it was the longest, most aggravating drive I've ever taken 45-50 mph on the interstate, and even slower uphill, you can imagine...

Back to the details, someone put a 2 barrel carter bbd carb and manifold on the truck so I don't know how it was running before the swap, but now it runs terrible and I need some pointers on where to start. The carb was missing the linkage to the choke and to the accelerator pump. It is also missing a lot of the vacuum hoses and has vacuum leaks which I plugged most of them and I rigged up a linkage for the accelerator pump, but it still runs terrible while driving it. It revs up freely and sounds pretty good if its in neutral. A guy from this site is going to send me a double barrel carb that came off a 318 so hopefully I can eliminate the carb being the issue.

But, I'm just wanting to know if there is anything else that I can check out while I'm waiting on the other carb to get here. Any advice will help me out because I'm clueless when it comes to these setups, I'm used to japan fuel injected crap...

-Thanks, Dillon
Author:  neilskiw [ Tue Apr 14, 2015 5:00 pm ]
Post subject:  Where to begin diagnostics....?
This vehicle is new to you, so you have little or no history to go on.

I hope you have some basic tools and basic mechanical knowledge. This will make it easier to understand the advise from slant 6 experts on this site.

Can you begin with a compression test? This will give you an indication of the condition of rings and valves. Without compression, you haven't got a motor.
Author:  neilskiw [ Tue Apr 14, 2015 5:07 pm ]
Post subject:  Next Step
Next I would check ignition timing, including visual inspection of the cap and rotor, and maybe clean or replace spark plugs.

A vacuum gauge will help you verify that you have plugged all vacuum leaks and also help you set the idle mixture.

Be careful of the BBD carb from a 318. Some have holes in the butterflies, and I'm told this will affect idle characteristics.

Slant 6 Dan has brand new 2 barrel carbs, and just think of the grief you will save yourself knowing you are bolting on a known good piece of equipment. And no, I don't get a commission.

Without linkage to an accelerator pump, every time you crack the throttle you let a huge gulp of air into the system. Unless you also have a healthy squirt of fuel from the accelerator pump, the mixture will lean out and give you the spit and sputter you describe. In neutral, when there is no load on the drive train, this will be less pronounced.
Author:  that4wdwagon [ Tue Apr 14, 2015 5:44 pm ]
Post subject: 
Thanks, and yeah, I feel like I've got a basic mechanical knowledge, and I have a fair amount of tools, should have enough to work with! haha

I'll do a compression test tomorrow as long as it isn't raining, been drizzly a lot lately :(. What numbers would be acceptable?

And I'll also check timing tomorrow too, I knew that timing light I just bought would pay for itself pretty quick! Already used it 3 times in less than 2 weeks haha. I'll check the rest of it out tomorrow too, I'm pretty sure the plugs need to be cleaned and probably re-gapped.

I'll check out Slant 6 Dan and ask him what he wants for a new carb, I'll probably end up checking this 318 carb out first since its ready to ship and I'm getting it a great price, so it can't hurt to have it laying around! If it has those holes in the butterflies, I may end up patching them up or something like that just to cancel that factor out.

Using a vacuum gauge is one thing that I've never had any experience with, how would I go about using one of those, or would it be easier to look it up on youtube?

Edit: Just seen what you said about the accelerator shaft; I haven't really test driven the truck since I rigged up that linkage on mine, I'm wondering if it helped any? Hmm, I'll check it out tomorrow.

Thanks for the advice so far!
Author:  xjarhead [ Tue Apr 14, 2015 7:07 pm ]
Post subject: 
Also check for vacuum leak at manifold and head.
Also check for vacuum leak base of carb.
Also check mounting bolts at base of carb are tight.

Dave
Author:  xjarhead [ Tue Apr 14, 2015 7:11 pm ]
Post subject: 
Quote:
Thanks, and yeah, I feel like I've got a basic mechanical knowledge, and I have a fair amount of tools, should have enough to work with! haha

I'll do a compression test tomorrow as long as it isn't raining, been drizzly a lot lately :(. What numbers would be acceptable?

And I'll also check timing tomorrow too, I knew that timing light I just bought would pay for itself pretty quick! Already used it 3 times in less than 2 weeks haha. I'll check the rest of it out tomorrow too, I'm pretty sure the plugs need to be cleaned and probably re-gapped.

I'll check out Slant 6 Dan and ask him what he wants for a new carb, I'll probably end up checking this 318 carb out first since its ready to ship and I'm getting it a great price, so it can't hurt to have it laying around! If it has those holes in the butterflies, I may end up patching them up or something like that just to cancel that factor out.

Using a vacuum gauge is one thing that I've never had any experience with, how would I go about using one of those, or would it be easier to look it up on youtube?

Edit: Just seen what you said about the accelerator shaft; I haven't really test driven the truck since I rigged up that linkage on mine, I'm wondering if it helped any? Hmm, I'll check it out tomorrow.

Thanks for the advice so far!


http://www.hemmings.com/hsx/stories/201 ... tips1.html

Dave
Author:  that4wdwagon [ Wed Apr 15, 2015 6:13 pm ]
Post subject: 
Alright, thanks Dave, I dug around in some old toolboxes that used to belong to my grandfather earlier, and found all kind of useful things!! Found 2 good vacuum gauges, 2 good compression testers, and a handful of other useful things(fuel pressure gauge, alt diode tester, plug wire resistance tester, 2 pretty nice looking timing lights, etc.).
I didn't get around to performing any diagnostics tests today though, hopefully I can do some of them this weekend. I'll check back in after I've done a few of the tests! Thanks y'all!!

-Dillon
Author:  coconuteater64 [ Wed Apr 15, 2015 7:54 pm ]
Post subject: 
Do you have catalytic converters? Mine ran like you describe and despite two different carburetors it still ran like crap. My converter was clogged up. Once I lopped it off and readjusted the carb, it ran great. For a while, anyway.
Author:  that4wdwagon [ Thu Apr 16, 2015 12:55 pm ]
Post subject: 
No, sadly my cat converter is gone, that was one of the first things that my dad and I checked. I wish it was that easy haha. Thanks for the suggestion though!
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