Just picked up a 1986 F250 4x4 with the 460, 4180 Holley Carb, and auto trans seems to be running rich and looking for some help.

Story behind the truck. My brother bought a house and they left the truck in the driveway. Previous owner came by and dropped off the keys. Said only needed a jump and it would be good to go. Surprisingly, that was it. Jumped it and drove it home (2 miles). That was all the info that I got from the Previous Owner.

Truck's last registration was 2012, so I'm going to assume it has sat for the last 2 years. The truck fires up pretty quickly without too much help from the accelerator. Choke is functioning properly after replacing the choke heater fuse. I have adjusted the main float level and have mitigated the amount of blue / black smoke while idling, but standing behind the truck you can definitely smell raw fuel on during idle.

The truck idle's a bit rough, but given the amount of time it sat, I don't expect it to purr like a kitten. What concerns me is that I live in CA and we have to pass smog, even on an older beauty, somehow the pre-smog year is stuck at '75. When I give the throttle a good pump, I get black smoke and a good gas smell. If I pump it real good, the truck will occasionally backfire (sounds to be combusting late in the pipe) as it is coming down in the rpms and then sputter and die, dipping below idle and then not able to recover.

I have checked the choke, accelerator pump, float level, and air filter. All original smog equipment is on the truck as I will need it to get the vehicle registered. As I understand, these Holley 4180's aren't really adjustable in regards to fuel / air mixture. What else can I check, adjust, or due short of a carb rebuild to adjust this? I was think of running some Seafoam in the tank to clear up the passages in the carb. I have already sprayed the carb and the idle inlets on the top of the carb.

Going to the store tonight to get a new air filter, vacuum gauge, and sv-cbv.

 

Check your power valve, could be blown or leaking causing a rich condition. The idle mixtures are adjustable if the plugs covering them have been removed, they require an allen wrench to set. There are 2 on the primaries and 2 on the secondaries. I would also inspect the EGR valve, sometimes a partially stuck open valve can give a false indication of a rich condition. When you gat it squared away I'll give you some sure fire tips on how to pass Ca. emissions.

 

honestly it could just be bad gasoline,

maybe run a long hose inside portable gas tank(with fresh new gas) to the fuel pump and see if the condition clears up?
obviously this isn't very safe and you shouldn't do it without safety precautions in place

 

The EGR looks to be the newest part on the truck. beetle - any tips on checking the functionality of the EGR? Smog tips would be much appreciated. This will be my first time with an old gasser. I normally stay pre-75 gasser of pre-98 diesel for the non-daily drivers to avoid haggling with smog.

On the power valve, it doesn't appear to be leaking out of the nozzle and the spray on acceleration looks good. Is there a way to check it without taking the front cover off the carb? I'm assuming pulling that off would mean a new gasket on there and from what I've seen to get the power valve, you're going to have to buy the whole rebuild set anyways.

I'm hoping it's just bad gas. The rear tank is about bone dry, so I'll grab a can in the morning and fill it up what I can and try running on that tank. There can't be more than a few gallons left in the front tank either. I'd like to just drive it to the station and fill it up, but with 2 year old tags and only a bill of sale I'm asking to get the truck impounded.

 

Welcome to the forum Woodzee.

Holley doesn't make a two stage powervalve any more.
You can check the instruction addendum for their 3-1346 rebuild kit on their website.
https://holley.com/products/fuel_sys...s/parts/3-1346
There are specific single stage valves recommended.

I would suggest if you are going to rebuild, you install a backfire check ball.
When (not if) your DSII module fails, it will take out the PowerValve.
https://holley.com/products/fuel_sys.../parts/125-500


beetle offers good advice, BUT, there is no 4 corner idling on the 4180c
Just the two screws on the front flange.

How many miles are on the truck?
This truck should have dual AIR pumps that inject air into the exhaust manifolds and the thermactor tubes at the back of the heads.
Without that air injection functioning a NON-CATALYST truck it will always smell rich.

Sloppy timing chain will do it too...

Run some fresh gas through it.
Maybe add a can of injector cleaner or old school Gumout.
Or a quart of Acetone, if you can get that in California.

 

ArdWrknTrk wrote: "beetle offers good advice, BUT, there is no 4 corner idling on the 4180c
Just the two screws on the front flange."

Hmmmm.........mine has 2 on the secondary and it's a Motorcraft 4180C, maybe there are some different versions???
OP, try the fresh gas first.

 

Beetle, we can go back and forth over this all day (and have before)

What's the list and build number on your carb?
I can assure you that the carb that came on my '87 F-250 ('86 manufacture) only had the two on the front.
Cannot say for the '85 5.0 Mustang GT I owned way back when.

"popping" on trailing throttle is a BIG sign of a blown PowerValve.
Get the genuine Holley kit I mentioned above (they are available on Amazon)
Off brand kits like Sorenson are a problem looking for a place to happen.

 

Amazon won't ship the Holley rebuild kits to the house. I tried work, home, the folks house, they all come back saying it won't ship. It will ship to my old address in TN but seems like there is some restriction on sending that part to CA, so parts have been ordered directly from Holley and I'll just have to be a bit more patient to wait for them to arrive.

I've got fresh gas and some additive to run through. New air filter, oil change, and a new fuse to replace the one I stole to replace the choke heater fuse. I'll get those done tonight and wait for part.

 

That's bizzare..
Its factory parts for an emmision vehicle.
Check pricing at a local APS.
I don't know Cali, but most stores deal direct w/ Holley.
They may have it in the warehouse.

 

Maybe Summit Racing will. http://www.summitracing.com/search/p...8%2B4294921694

 

Holley will ship.
I meant if it was needed asap.

 

Ordered direct from Holley. I was at 2 of the local AP stores yesterday and was not impressed. Looking online neither had them in stock so figured I'd cut out the middle man. Should have them in time for the weekend. Just enough time to unpack the rest of the tools.

 

No worries my friend, I'll let you solve the mystery Secondary bowl w/ mixture screws below.

 

There should also be some numbers stamped on the air horn

 

Are you saying there are adjustment screws in there? It looks like brass plugs pressed into the casting to me.