I think I have a minor issue with the truck.

79' F150 4x4 std cab
74' Linc 460, 750 Holley
4spd

She is getting tough to idle after first startup. Once she warms up she idles and runs well. When cold, at idle, the idle wants to drop off, almost stall.
She seems to "lope" a little when cold too. She will start right up at the bump of the key.

When warmed up, she runs really good, pulls good, idles fines, starts well.

She smells rich to me when running. I just hooked up a vac gauge and am pulling steady vaccum. I haven't tried dicking around with the mix screw yet though, thought maybe I'd get some opinions.

Timing is set to 8 or 10 BTDC, I can see my line from a while back, but can't read the numbers.

I noticed the choke (electric) is set where it's all the way forward on the adjustment notches. I'm not sure this is correct.....

The carb, also looks sooty on the inside, like it needs cleaning, it was new 2 years ago, and after pulling it out of storage, I had a friend of mine clean and re-build it. Really only gaskets, but he still went thru it.

I'm running 93octane, that's what the previous owner ran in her, she runs like hell on anything lower, but I figure that is just the setting the carb and retiming her to compensate for the lower octane.

Thanks for any input or advise,
Blair

EDIT: Forgot about the backfire. She had only been idling for a couple minutes, I had shut her down before she got warmed up, I was hooking a trailer by myself. I got back in, hit the key, boom!! A blck cloud of smoke and she was running. Once warmed up, she ran great.

 

Sounds like you're running really rich, and possibly timing advanced too far. That's probably the reason for the backfire. Pull your plugs - they can tell you a lot about what's going on.

 

I should have thought of that.

I guess that would tell me alot about what I have happening.

Thanks.

 

This is all fresh on my mind because I just went through a spell on my CJ7.

How many gas stations can you pass with your 460? I had a '70 F100 with a 460/750 setup and that thing could scoot - but loved stopping and getting a drink way too often!

 

I got a CJ too. 79' CJ7. Searching the pick n pulls for a Motorcraft 2100 as we speak. Couple more things and she'll be road/light trail ready.

Truck does alright. I've been thinking of getting a bigger tank. I heard you can get a aftermarket 30 some gallon one. I'm setup for two, but don't like the behind the seat tank. She does decent if I keep my foot out of it, the more I learn and the more stuff I fix from the jackass owner that had it before me, the more I love the rusty beast.

I just pulled a 20+ flatbed two axle trailer with a 48 ****** panel truck and several chassis stacked together all at once with my truck. She did awesome. Not bad for a 26 year old truck with a 31 year old motor that's never been rebuilt to my knowledge.

Thanks again for the tip.

 

The 2100 does GREAT. I wish I hadn't waited so long to do the swap. I've been running a Weber for a couple of years. Ran great but always rich. The 2100 with the HEI upgrade is the way to go. I was running with the TFI upgrade and it ran much better than stock and didn't think I would notice the difference in upgrading further to HEI. All I did was swap out the ignition module with an HEI module and it ran better than new. I was very impressed and disappointed that I waited so long.

Good luck with your big ol' girl and the CJ.

 

Thanks man. I was looking to upgrade and kept putting it off too. I've been looking around here and am about to go for Ebay. Just not a lot sitting in the yards anymore, most are picked already. The HEI is on the list, I may try to do it at the same time. But I've heard it's sooo worth it. Can't wait to get this one rolling, I sold my last one and instantly regretting it. This CJ has almost no rot. I think I'm in good shape.

Pulling a plug from each bank on the truck tonight. I'll post how they look.

 

Hey Bigunns, Haven't seen you around in awhile.
You have the classic carb icing that these trucks are so famous for. You need to run a stock air cleaner with the heat riser in the winter or the idle circuit air bleeds will ice up which chokes the airflow and makes them run really rich until the underhood temp rises enough to keep it thawed.
Jimmy

 

78bigunns, I just noticed where you're from. I used to head out your way every chance I got while I was stationed at Ft. Belvoir. Loved getting away to the Shenandoahs!

 

Hey Lx. It has been a while. I still troll and lurk a good bit. ONe of my fav things to do in the evening in sign on and read all the posts. You can pick up alot on this site and that's putting it mildly.

I blocked of the old choke stove assembly that was on the old Holley when I slapped on the new toilet bowl 750 I'm running now. I have a big Holley 14" or so chrome air cleaner. Could I fab a choke stove ***'y and pipe that into the carb?

What do you guys think about the elec choke being set all the way forward? I haven't played with it yet.


Scottlane,

Yea man, the mountains are fun. The Jeep club runs out monthly if not more often to trail ride at GWNF. My sister actually lives on the mountain down at Massanutten resort. Really nice down there.

Blair

 

Sounds to me like your choke is set too rich. If the truck settles down and runs fine after warming up, I wouldn't touch the idle mixture screws at all. Try this. First thing in the morning, set the choke. Then remove the air cleaner and adjuts the choke so it is just closed. Lock the choke in this position. Have someone else start the truck and watch the plate. It should open slightly after the engine starts as the vacuum pulloff activates and pulls on the choke plate.

 

Blair, You can keep the carb, but the open element air cleaner will give you these icing problems all winter long. I went thru this for a couple of years before I figured out what was going on.
If you have a stock air cleaner (it will fit with the Holley), you can run it in the winter. I have to do this on my 460. I have headers so I made a piece that fit loosely around one of the header tubes to hook up the air hose to bring warmed air into the carb. There are some pics in my gallery I think. I don't think that you have a choke problem.
https://www.ford-trucks.com/user_gal...=62258&width=2

Jimmy

 

I bet I could dig one up. You don't think my choke should be messed with? I've never played with it all since I never drove the truck that much. But now I'm using her more and more.

I still need to pull a plug, if it's only running rich on startup due to the carb icing, the plugs should be relatively clean then in therory right? They'd burn off the gunk from being rich for a few minutes at cold idle?

Blair

 

Yeah, after driving around a bit after it has warmed up and idling fine, then I would shut it down and check the plugs, I would say they are OK. You might just check the choke when it is cold, push the gas to the floor once, then check the choke plate. It should be closed but not real tight. It should push open by hand and then close back without snapping hard. Then start it up, it should slowly start to open, when it starts loading up after a few minutes, touch the mixture screws. I'll bet they are ice cold, if not frosted over. If this is the case, round up a stock air cleaner and hook up the hot air system on it, I'll bet it clears right up.

Jimmy

 

Thanks. I'll see if I can dig one up at the pick n pull Saturday morning. Headed there for Jeep stuff anyhow.

Blair