Help for a new guy
 

Hello, new member and aspirational 1966 GMC owner. Realization of dream I've has since I was a kid. Anyway, I'm looking at a 1966 GMC "custom" edition with a non-original inline 6 for $1500. The tags expired in 2001 and it's been sitting for the last 2-4 yrs. When I started it, it ran really rough and stalled when I pushed the choke in. Smelled horrible. I was able to drive it around the neighborhood, but had to leave the choke on. I came back a couple days later to drive it again; it started easier and ran a little better. However, I couldn't get it over 35 MPH on the road without it lurching and stalling multiple times. I would've bought it that night if I thought it had to be the potential to be a daily driver.
So my question is....I'd take it if the problem was simply old gas or something simple. I don't have the time, money, or expertise to deal with a complex problem. Are there some tests I can to do determine if it's a simple problem or a truck I should walk away from? Much appreciated!

Re: Help for a new guy
 

My guess is that it has sat long enough to gel up the gas. You'll probably need new gas, a carb rebuild (very simple weekend project), and new fuel filters. If it's really nasty gas you might have problems with the sending unit too. That's the thing that tells you how much gas is in the tank. It's another easy replacement though.

The great thing about these old trucks is that you can fix them with about 8 tools. And if you need help with it there's 500 people on this site. Chances are pretty high one of em knows how to do what youre wantin to do.:goodluck:

Re: Help for a new guy
 

Disconnect the inlet line from the fuel pump. Attach a length of hose to the inlet port and stick the other end in a can of fresh gas. If the engine runs better now, you know what the problem was. If the carb is gorped up badly enough, you may still need to clean it out, especially all the small passages, before the engine will run normally.

Ray

Re: Help for a new guy
 

My guess is that it has sat long enough to gel up the gas. You'll probably need new gas, a carb rebuild (very simple weekend project), and new fuel filters. If it's really nasty gas you might have problems with the sending unit too. That's the thing that tells you how much gas is in the tank. It's another easy replacement though.

The great thing about these old trucks is that you can fix them with about 8 tools. And if you need help with it there's 500 people on this site. Chances are pretty high one of em knows how to do what youre wantin to do.:goodluck:[/QUOTE]

>>>The fuel gauge is stuck past full so that's another potential clue I guess. Thanks for your help!

Re: Help for a new guy
 

>>>Ray and pepsi, great ideas and thanks for the posts. What would you folks do next? I was thinking about adding some fuel stabilizer to the old remaining gas then adding some fresh ethanol-free gas to the tank. Maybe a new fuel filter. I'd like it to be able to run >50 MPH to get it home where I can do some more TLC like rebuild the carb and replace the plugs?

Re: Help for a new guy
 

I wouldn't drive it that fast being that it's a new to you truck. Maybe 40-45 max downhill with my buttcheeks pinched together but that's me. I'm risk averse lol.

If it was me my next step Id trailer her home or drive her slow (30-35 mph) with my wife or a friend following me to make sure I made it. Carry some tools for simple repairs like screwdrivers (both kinds) needle nose pliers, a set of wrenches, and a belt for the engine or some pantyhose from the wife. And a couple of gallons of distilled water in case she overheats. And a quart or two of oil. You never know on a new-to-you truck or car. Part of the fun is finding the trouble and fixin it :yeeuh:

Then Id get a pump and pump all the old gas out into a gas can. Dispose of as you think you should.

Then Id bang on it a few times with my hand (not a metal hammer or a road flare :lolsmack: ). Aim at that big round bolted in spot in the middle to see if you can knock the sending unit loose. If you can get it to fall down it might work great after that and a new batch of gas. If you hear it moving around it might be the gauge that's bad or dirty. Dirty is an easy fix if you're careful. If you wait a few days to air out you can safely undo all those bolts and just pull the sending unit out and soak it in carb cleaner if it's not moving freely.

Finally I'd replace both gas filters if you have both. One under the cab and one by the carb. After that it's off to Napa for a carb rebuild kit. Take a weekend and take your time. She'll probably run without it but you'll end up doing it anyway soon and its only 15 bucks. Best 15 bucks I ever spent on Cecilia.

Congrats on your new truck! Where are the pictures :D

:goodjob:


Oh I forgot to add if you turn the key off and the gas gauge doesnt move its probably electrical. It can be both though.

Re: Help for a new guy
 

Good advice to follow from these guys. I would try a clear plastic fuel filter between the pump and carb too and keep an eye on it to see if a lot of debris collect in it. Rust or dirt from the fuel tank will be visible.

In 2009 I got a '55 GMC with a '66-'68ish Chevy 230 in it and the truck had been sitting in a field for 14 years prior to that. I was very fortunate the tank was clean and was able to drive it home like Fetch recommended while my wife followed. I rebuilt the carb and the fuel pump arm was broken but stroking enough to get a little gas. Replaced it. That was just to get it home. It has been my daily driver since 2011 when the title mess finally got cleared up and an aweful lot more time and work has been put into it but not a lot of money.

My point is you asked if you should walk away from it. That is a hard question because it depends on desire to work and learn because there will be work to do, but it can be done yourself. If you want something you could just fix the carb and start driving, problem free, this probably isn't going to work out that well as there is always something that will arise while driving an old truck! The more you can do yourself, the less you will spend.

Later---DAC

Re: Help for a new guy
 

Thanks, folks. I haven't bought it yet (the guy selling it went on vacation, so I have some time to think about it). If I do, I'll definitely post. I guess if I trailer it home, maybe I can give the guy to give me a break on the $1500!

Re: Help for a new guy
 

My first question isn't about how it runs cause that's just a bonus. Nothing on these trucks is to complicated or expensive to repair if you have basic skills and a forum like this to help out on things you don't already know.
My first question is what shape is the body in? If that's good, complete with tailgate, then that alone is worth over $1500, as body work and rust repairs wiould cost a lot more than that.
Everyone here is right, you give her a fresh gas load (maybe a tune-up & carb job) and away she'll go! GOOD LUCK!

Re: Help for a new guy
 

It has the rust spots behind the front wheels that they all seem to have if not restored previously. I think the fenders are relatively easy to replace. There is one bad spot over the left rear wheel on the box, but looks like it can be repaired. The wood on the bed is in pretty bad shape, but that too can be replaced. Other than that, the rest is pretty solid. A pic is attached. Thanks for the help!

Re: Help for a new guy
 

Wow that is in much better condition than you made it sound, your rust is almost non existent that ruck would sell for $2k-$3k here like that running or not if the cab is rust free.

I never understood why so many GMC's have Chevy hoods like this and your rig even has "chevrolet" mounted in the GMC grille, funny that people change this stuff.

Very nice condition, I don't know what the market price is in your area but i would snap that up NOW for $1500 in the condition. And if they negotiate the price a little all the better!
Good Luck!

Re: Help for a new guy
 

Dang man! 1500 bucks all day long on that custom there unless the other side is completely missing! Being Idaho you're lucky it's not rusted through the floorpans and 1/2 of everything else. Haggle with him if you want but you take that puppy HOME and love on it daily! Great color for these old trucks too.:goodjob:

Re: Help for a new guy
 

That truck already looks like the work could be minimal to make a decent driver out of it, and like you say, bed wood, fenders etc, are basic stuff to replace. I say buy it!

Later---DAC

Re: Help for a new guy
 

Nice looking truck New Guy. My two cents worth: If the rest of the truck is in as gooda shape as the picture shows, it could be a nice truck for you. That really depends on what bed style you want, how much work you want to do, and whata ya want the truck for? Project? Daily Driver? Work/Ranch truck? Only you know those answers.

If you should decide to get it, I would strongly recommend trailering it home. You could do damage to the engine by driving it around, especially at highway speeds. If it's been sitting that long, it needs a "start up", which would be dealing with the old gas in the system, which has already been talked about. Drain all that crudy old engine oil and change the oil filter. Inspect what comes out in your oil pan and whats on/in the filter cartridge. It could tell you alot about the condition of internal things. Check out the brakes real good. If you have a good strong pedal when you push on it, then at least do a visual inspection of the master cylinder, and crawl underneath and check the wheel cylinders for leaks etc. Cooling system? Any water leaks at the radiator? Are the radiator hoses in good shape? Pinch them and see if they still are flexible and not brittle. Hows the fan belt? If all this stuff gets done and you get it fired up, then watch the gauges real close as the engine warms up. Temp gauge ok? Oil & Gen lights work with key on, but stay out when engine running? Any smoke coming out of the tail pipe? Anyway, lots to consider, and a fun project for sure. Treat that ol' girl to some TLC :goodluck:

Re: Help for a new guy
 

OK, folks...I bought the truck! Thanks for all your help. Now the fun begins!

Re: Help for a new guy
 

Nice! I just brought my 62 home Sunday and it is already running. I did and do have spare parts motors so that helped quite a bit.

Most of these GMCs have a fuel filter in a canister slightly smaller than a Coke can under the cab on the passenger side. They are really cheap, like 4 bucks. Change it and carry a spare with a clear filter nearer the engine to keep tabs on what is going on in the tank.

Re: Help for a new guy
 

OK, I drained as much of the old gas as I could and put a couple gallons of fresh ethanol-free gas in the tank. The filter in the carb was half blocked with crud. Replaced the fuel filter next to the gas pump with a clear one, and it looks dirty already. There's no filter under the cab. After all this it still idles really badly. Can't idle for long even with the choke on full. Any thoughts about how to clean things up?

Re: Help for a new guy
 

I would scroll back up to Fetchmeapepsi's comment and click on his carb rebuild link in his signature. He really did a great job writing it up in basic terms.

Re: Help for a new guy
 

Yeah if the carb filter was that bad the inside of the carb likely has bad gummed up old gas residue and you should just buy a new carb or do the rebuild, they are so easy to redo yourself that you will be surprised. Do the carb and tune her up and you will be flying done the hiway!

Re: Help for a new guy
 

:champagne:

Now start a build thread and lets see some pics of all the progress! Welcome to the obsession :lolsmack:

Like another person said I think I see a 15.00 carb rebuild in your future. If you dont already have some get a gallon of carb cleaner too. You can reuse it again and again on everything greasy. Money well spent!

I think it was $16.00, but I dont remmeber. That and a few screwdrivers and sockets are all you need to get-r done. Youll be driving in no time.

Re: Help for a new guy
 

If the filter was cruded up like that, and it still runs rough, like most of these ol' dogs that have been sitting, you might consider taking care of the entire fuel system. Start by cleaning/flushing the gas tank. Then the fuel lines, the in-line filter, the fuel pump, and then rebuilding the carburetor. Now then,,not everybody can jump right in and rebuild a carburetor, no matter how "easy" the experts say it is. If your not comfortable digging into that carb, consider spending the money and having it done professionally. After that's done, and all the parts are back together and adjusted properly, your entire fuel system (not just parts of it) have been gone thru and should work well for you. And like you were saying Vern...."The fun begins".

Re: Help for a new guy
 

I hope you are happy as a clam with you new acquisition, it looks in such nice shape for that year, will be a great ride and get lots of looks.

Regarding the carb rebuild, don't fear it is a job anyone can do especially if tinkering with mechanical things is your thing! Just FYI; a carb kit on RockAuto.com is about $14 + cleaner fluid, and a NEW carb there is only about $120 with a core return. A professional rebuild may cost you 2-4 hours of shop labor so depending on your local shop rates that could run you over $100 maybe even over $200, easy to call and get a price.
If your thing is to learn while you tinker with your truck then with the kit and instructions and the internet(youtube) you absolutely can't go wrong and you will learn and enjoy doing it yourself(like all of us did)for only $14, you might find a kit locally for $15-$20. just read the tag numbers on your carb or take the carb to your partsman to look up.
If you rebuild it instead of buying the new one there is always mechanical help on here to help you out and I'm sure there is someone around your area as well. The worst you can do is waste a little time while learning something new even if you end up needing extra help, anyone here will jump right in. Good luck the best way to learn is to "Just Do It".

Re: Help for a new guy
 

Wow, thanks for all the input! I thought about rebuilding the carb myself because I know a guy that could fix it if I really screwed up. I'd rather do things myself when I can.

The only thing that makes me wonder is whether it would be worth the money to upgrade to the 2BBL Holley carb that seems to be recommended on this site? $150 for a little more power, even though I'm not interested in going fast? The engine isn't the original, so I'm OK with changing some parts to newer stuff.

Re: Help for a new guy
 

$150 is not bad but what does it do to your fuel consumption, has anyone commented if it turned out better or worse for them?
There is a lot of info online about I6 mods for performance etc. depending on what your desired out come is! If you have the budget maybe do some searches on these things before you go in any one direction and see what peaks your interests.

LOL, Of course keep in mind that one idea leads to another which is another way of saying that $50 can lead to $500 and to $50,000, there is no shortage of ideas and modifications as long as there is no shortage of $$$.

Re: Help for a new guy
 

Glad you bought the truck, Vern! Without more detailed descriptions or pictures of your engine, it is difficult to help. I couldn't find if you may have said what your I-6 is. If you have a Rochester model B or model M one barrel that Holley won't be a bolt on deal. We just need to know and see more of what you are working with.

Later---DAC

Re: Help for a new guy
 

I thought you had to be a psychic to post on this site? :)

First things first; the compression tests came out: 122/125/122/120/122/110. Does this make this engine a keeper?

Attached are some pics of the engine and carb. Based on the casting#3921968 it's a 230 or 250. The suffix is F1209TCB; still trying to track down that number.

Thanks!

Re: Help for a new guy
 

I think you have a 292, it looks like it has the large side covers over the lifter bays and I think it looks like there is a space between your thermostat housing and the water pump pulley. If this is right this would indicate 292 engine.

I there is no space between the TS and WP pulley then it is probably the 250.

Re: Help for a new guy
 

Hello Vern, I have one of those engines with the same casting number and mine is a 250. The casting codes at inliners site also verifys what you said. The first 2 pics are of the 250 I have stored with the same casting number as yours.

The 3rd pic shows the carb on the 230 in my '55 GMC. It looks like you have a Rochester Model M like the one on this engine. That is a 1 bbl carb so to put the Holley 2 bbl on you will have to get a 2 bbl intake manifold also.

I forgot to add that I don't see any major problem with your compression numbers. The 230 in my '55 has numbers similar to yours. Mine uses a quart of oil about 800 to a 1000 miles. That falls into a "good" catagory for me anyway. It runs great and gets real good milage considering the brick shape it pushes thru the air!

Hope this helps---Later---DAC

Re: Help for a new guy
 

I went through the tank cleaning process this weekend and mine was too far gone. The new tank was $160 and with a sending unit and new fuel neck hose I broke $200. I picked it up so shipping could be a little high because it is big.
The piece of mind is worth it in busy Vegas traffic and 110° days.

Re: Help for a new guy
 

OK, clearly the tank is shot and I got another one (and sending unit). When I ran some some clean gas from a can through it the engine purred like a kitten.
Based on the pics can you folks point me in the right direction for a carb kit? It's a 230/250 based on the casting numbers. There's a youtube video I think I can follow, but I want to make sure I have the right kit. Thanks!

Re: Help for a new guy
 

I think you won't have any trouble if you get a kit for a 66 rochester monojet. I am 99% sure that was a stock I6 truck. Everything looks correct. The vin # will confirm this. Second thing if you get to spokane let me know. I will give you some gmc grill letters. Free of charge. Barry

Re: Help for a new guy
 

Now you are getting somewhere... sorry, no help on that carb other than I think I have might one laying around that I can send you if you really get in trouble. I will take a closer look when I get a chance.

Re: Help for a new guy
 

Hey Vern, wife and I took the '55 on a trip for a couple of days. Just got back. Incase you didn't get a carb kit yet, here is a closer pic of my carb and a couple of the kit I used in it.

Later---DAC

Re: Help for a new guy
 

Hi Vern just wanted to say hello from North Idaho I live about 8mi nw of CDA at Rathdrum. My truck is a 65 custom granny 4sp and a 230 engine. I had the same problems with dirty tank lines and filters when I got it clean it run like a new one. The truck came off a farm in Western Mont. up near Havure and it sat allot but it started up and run long enough to get it on a trailer. Oh and my name is also Vern but I use Vernski from 60-66 truck forums handle.:lolflag:

Re: Help for a new guy
 

Yea, I live north of Moscow (we're practically neighbors by N.Idaho distances). :lolflag:

I rebuilt the carb and replaced the fuel pump and lines to the carb. I got it to start and idle but it was pretty rough. Hopefully I'll wrap up replacing the gas tank and the rest of the lines this weekend.

Re: Help for a new guy
 

If you were closer I have a clean gas tank from a '64 Chevy pickup and the steel fuel lines you could have.

Later---DAC

Re: Help for a new guy
 

Well, the tank, fuel lines, pump, and rebuilt carb are installed! Unfortunately, there's a ghost in the system somewhere. Idles great, but about stalls out when you step on the gas.

Re: Help for a new guy
 

My guess would be that it's timing light time! That's what mine was doing and I ended up having my timing set at some goofy number like 30 over. you can buy one from autozone and return it if you need to but it's good to have one on hand from time to time. :goodluck:

Re: Help for a new guy
 

OK, I replaced the distributor cap, rotor, wires, and adjusted the timing. Today I drove it to a shop on the maiden voyage to get the brakes inspected. When I pushed the choke in all the way and tried to get it out of first, it stalled every time. When I pulled the choke out a little bit, I was able to drive it. Very rough and my wife complained that I smelled like an old gas rag when I got home, but I was able to get it up to 50 MPH. Any ideas about what is going on?

Re: Help for a new guy
 

If you're smelling gas it could be your mixture is too rich now that your timing is right. The idle mixture screws might be too far out or (i doubt this) your acceleration linkage needs adjusting. That involves bending the rods though so Id do that as last resort.


Too you got to remember that theyre old trucks without all the fancy catalytic converters on them. theyre gonna smell somewhat like gas. dont run them in a closed garage lol. :poke: