First drive since 2006....have a few issues and need some help.

[thefarmboy21]

Well I just got and 86 K20 from my grandpa and took it out for the first real drive yesterday. It was the first time it has touched the blacktop since 2006. A few months ago was the first time it had even been started since probably 07 or so.

Anyway it's got a few issues that I need to take care of. Some probably just from sitting and some that I think he had problems with before he quit driving it.

1. The parking brake comes on when you start moving and goes off when you stop. The brake pedal is all the way up and it doesn't seem to be engaged in anyway.
2.The windshield wipers work on low but complete stop if you switch them to high.
3. Does it have backlit dash lights? If so they don't work because I turned the headlight knob all the way clockwise (I assumed that adjusted the brightness) and they don't come on at all.
4. My gas gauge constantly moves back and forth (tho I thought maybe the old time senders just acted this way)
5. My radio doesn't work

It needs a good tune up too...it sputters and falls flat when you shift and get back into the fuel. When you tromp it it really falls on it's face. AND the old 4-speed shifter has some slop and makes it harder to find the gears...tho not near as sloppy as some I've driven. Thanks!

[Captkaos]

1. I am assuming you mean the Brake light.  Check where it plugs into the parking brake, should be a tan/white wire going to up to the cluster and then split out and back to the harness.
2. this could be a bad motor
3. Yes they are backlit, check the wiring behind the cluster, could be related to #1's issues
4. Several posts and a Tech article on this.
5. See 3 and 1, check the wiring.

[thefarmboy21]

Yea I meant the brake light in the dash. The gauges all seem to be working, tho I don't know if they're all working properly, but they work. I'll check all my wiring, fuses, etc and see what I can figure out. The choke light was staying on all the time but now it's the brake light.

[thefarmboy21]

Man, doing this stuff on an iPhone at work on a forklift gets confusing. I keep posting everything in the wrong spots haha

[Captkaos]

Rebuilding the carb won't hurt.  I don't think I would hack the exhaust up if you already blew stuff out of it.  Is anything flowing out of the exhaust?

Merged these together as they are semi related.

[thefarmboy21]

I keep trying to start a new post in the drivetrain forum and it keeps posting it here. I've tried three times and it keeps showing back up here. I've never had trouble before lol. I'll try again.


It keeps ending up here because of what I put in bold above.  This post is related and I keep merging them..  - Captkaos

[thefarmboy21]

I recently got an 86 K20 off my grandpa and finally took it out on the blacktop yesterday. It has a 292 and hasn't seen asphalt since 2006 and hadnt been started for SEVERAL years until a couple months ago. I drained the gas, dumped a bottle of lucas and a bottle of heat im the tank, changed the fuel filter, air filter, changed oil and replaced a few vacuum lines. It runs pretty well all things considered, but it sputters and falls flat when you shift. If you try and do it smooth it sputters a little before it picks up, but if you tromp it it just falls on it's face before it comes back. Also if you rev it high and let off the fuel while in gear, you can hear it kinda cough once in a while. Almost like a puff sound. I don't know if it's in the carb or exhaust tho. I plan on an ignition tune up, but other than that I don't know. I'll probably clean the carb too, maybe rebuild it. The exhaust had a mouse nest blow out of it twice, so I'm considering just cutting it off in fear of a clogged muffler. 

Part of the problem is that my Papaw bought it new, it had 78,903 miles on it when I took off yesterday. It's never been more than 30 miles from home since he bought it and he drove it just like you'd expect an old farmer to drive it....like an old man and constantly through fields. So I'd say that it needs the guts ran out of it really good haha. 

Also, just like a lot of the old granny 4-speeds, the shifter has some play in it and is hard to find gears sometimes. How do I fix it??? Thanks!

[Irish_Alley]

if you cant find them, grind them lol. the only thing i know you said you replaced a few vacuum lines just make sure you dont have any vacuum leaks any wear

[thefarmboy21]

Yea I'm gonna go over my vacuum lines again and then Im pretty sure I'm gonna rebuild the carb and clean it all really good. Ive torn into just about every style of carb at some point....I can't imagine these are too complicated.

Are there any disadvantages of deleting the smog pump?

[Blazin]

With 79,000 grandpa miles on it the shifter should still be nice and tight. Has someone put a different trans in at some point, with more miles? Or abused it? The SM465 in my 86 K2500 has almost 245,000 plus on it and it still shifts nice, and tight. Still makes that nice positive snap sound when it goes into gear.
If you haven't tuned it up that would be the first thing, but it sure sounds like the carb is varnished up inside.

[Fairlane514]

Sounds like the accelerator pump on the carb is not working.

[thefarmboy21]

It's not the worst by any means, but my 77 K10 with 96,000 is tighter. It's probably only got a couple inches of wiggle. And the gears hit nice and tight. It shifts great as far as that goes just the shifter is loose. Some just seem to lastomger than others from my experience with the old 4-speeds.

Yea I would say the carb is varnished and I agree on the pump. It acts the same way as the Edelbrock 650 Avs on my 350 derby motor. That's what's wrong with it...doesn't squirt right. I've gotta pull the tranny out and change the throw out bearing next week and I'll probably tackle all the tune up stuff too.

But FYI he has tons of old NOS parts in the truck. One of which is a box of old AC spark plugs. All in the original sleeve and original boxes. They were never installed. Look brand new and have the green AC symbol on the sides. SCORE!!!

[Jason S]

My $0.02 is remove the carb and put a kit in it.  Don't adjust the float setting, just clean the carb, reassemble and install.

[1980c10]

 The tack welds that hold the ball onto the shifter tend to crack. this leads to loose shifting and a noisy shifter going down the road. you'll need to remove the shifter in order to inspect this but you'll know exactly the area im talking about when you get a good look at it. I'm sure these could be welded over; however I never tried as I had a chrome shifter I found from the u pull it to put in. The replacement was in great shape and made a world of difference in how it shifted. btw I'm sure it had more to do with defective welds than miles with these shifters. Not sure if this is the problem, but it was with mine and is really easy to check.

[thefarmboy21]

Yea I usually don't mess with the floats and stuff....just clean em and put a few new parts in em. I'll have to pull the shifter anyway cause I've gotta drop the tranny.