85 W250 318 high idle and running rich

Blue Chaos · Sep 15, 2015

Titles says it all. When I start the truck or come to a stop or out it in park it idles high. Like to the point where I shut it off and it keeps wanting to run and makes a diesel sound. Only does it sometimes though. And it is definitely running rich, but from what I hear these carbs are not adjustable. Any ideas for either problem??

RonJon '06 · Sep 16, 2015

What kind of carb do you have? The idle speed on the carb should be adjustable. A while back mine was idling high and running very rich, turned out one of my vacuum hoses was disconnected.

Blue Chaos · Sep 16, 2015

I have a few disconnected hoses... Haven't figured out where they go. And a 2 barrel

RonJon '06 · Sep 16, 2015

My '85 has a sticker with the vacuum diagram on the underside of the hood. If you get stuck post some pics and we'll try to help you figure out where they go.

crazzywolfie · Sep 16, 2015

the best place to start is to make sure there is no vacuum leaks. the carbs should be adjustable but the adjustment screws are in a real pain in the ass spot to get at especially if the truck has a/c. the adjustment screws are pretty much at the base of the carb under the float bowl.

Blue Chaos · Sep 19, 2015

OK found a vacuum line disconnected. One of the two that goes into the bottom of the breather. I also just did a smog pump delete, it was locked up and belt cut anyways. The idle is back to normal but she is still running rich. Also I think there is a hole in my driver exhaust manifold because I can see plumes of exhaust while the hoods up, but it's really hard to see where they are coming from.

crazzywolfie · Sep 19, 2015

the smog pump hooks into the exhaust system so usually you need to block some of those tubes that ran to the smog pump if you removed it.

Blue Chaos · Sep 19, 2015

I did. But I noticed this exhaust in the engine bay before removing and after fixing the vacuum line

crazzywolfie · Sep 19, 2015

well if the exhaust manifold is leaking you probably should be able to hear it.

Blue Chaos · Sep 19, 2015

It's loud as hell. The exhaust rusted apart 2 feet past the manifolds so I can't tell if it's there or the pipes. Once I get them fixed I will be able to tell. Plus I wanna do headers, valve covers, breather carb and intake manifold. I'm sure I'll find the problem somewhere in there. And I want to delete the charcoal cans egr delete. All emissions crap

crazzywolfie · Sep 19, 2015

lol ya you will find the issue eventually. also when you go to do an intake/carb swap that may also be a good time to do a cam swap since you would have so much open. the stock cam are ok but most stock engine respond a bit better with at least a towing/rv cam

Blue Chaos · Sep 20, 2015

Yeah I have thought about it. But then I might as well do a double roller chain and new gears lol. Mooore money.

crazzywolfie · Sep 20, 2015

a new cam/lifters and a new timing chain/gears would not be too much more of an expense compared to a intake/carb. i think you could probably get them for about $200 from summit as long as you don't mind summit brand stuff.
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The War Wagon · Sep 20, 2015

Blue Chaos said:
And I want to delete the charcoal cans egr delete. All emissions crap

That's easy enough - just plug all your vacuum lines when you do. The right size screw, and some silicone, makes a GOOD line block, FYI.

DO make sure your locale does NOT require emission testing though - including VISUAL inspection. You may hafta get creative with blocking actual lines, while running DECOY lines off that can, to pass a VISUAL inspection! :naughty:

crazzywolfie · Sep 20, 2015

I can tell you from experience don't plug the gas tank vent at the charcoal canister if you do remove it. It will cause your engine to flood when it is not running

Jimmy68 · Sep 20, 2015

Lol. Your first and foremost issue is that two barrel Holley.
Even if you can't afford much, swap the intake and carb first thing. Then get headers and do up a nice (read cheap) exhaust. Also get copper flange gaskets. Not the stock paper ones that come with headers, they burn out fast.
Cam, lifters, rockers are all sweet. Save up and buy a nice set.
Good roller cam and lifters will do wonders and a sweet roller rocker set will make it all pop.
Easy bolt on's that will clean up and make you smile.

Blue Chaos · Sep 20, 2015

Jimmy68 said:
Lol. Your first and foremost issue is that two barrel Holley.
Even if you can't afford much, swap the intake and carb first thing. Then get headers and do up a nice (read cheap) exhaust. Also get copper flange gaskets. Not the stock paper ones that come with headers, they burn out fast.
Cam, lifters, rockers are all sweet. Save up and buy a nice set.
Good roller cam and lifters will do wonders and a sweet roller rocker set will make it all pop.
Easy bolt on's that will clean up and make you smile.

I can't wait for that day lol. Yeah I plan on doing that all. Oh and wagon Indiana has zero emissions checks visual or otherwise. And wolf, I watched that video the other day lol. I'm thinking about getting all the parts and doing it all in one big bang. Of course it will take a little time

crazzywolfie · Sep 20, 2015

at least if your patient you might be able to find a good deal on a used 4 bbl intake. as far as the carb goes i am not sure if you want to buy used and rebuild or not. it is always a gamble when you buy used. you never know if it has issues or not till you toss it on.

Blue Chaos · Sep 20, 2015

What would the 4 barrel come out of? It is oem or would I be waiting on someone to go EFI or back to a 2 barrel, speaking of intakes not the carb.

crazzywolfie · Sep 20, 2015

well i think a lot of the time most people usually end up running 360 4bbl intakes on there 318 because you can usually find a stock 360 4bbl for cheap since they are pretty common. yes they are a bit heavy but on a truck it will not really make any huge difference compared to an aluminum intake.

85 W250 318 high idle and running rich

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