HELP!! Cant decide.

[LinseyAnne]

I have a 72 GMC 1500 Custom straight 6 and it was my grandfathers, he bought it brand new in 72 and then my cousin took it when he died and let it sit and ROT for 8 years not doing anything to it. I did a little tune up on it and got it to RUN for a while. It needs a new carb. definitely and just recently I noticed that it couldn't possibly be running on all cyls. I am stuck with the decision of getting a new motor and just keeping the old one to fix in my spare time ( I am a total NOVICE fyi) but I sell cars for a living and this is my new pet. It has sentimental value to me and I want to make it beautiful again. But first things first, I want it to RUN GREAT, then I will make her pretty. I want to use this truck as a daily driver. I know that I can get a decent motor for it pretty cheap and I have someone that will help me pull it and put the new one in. But Darn its really expensive to FIX it rather than put another motor in it thats good to go. Should I try and keep the motor and just slowly replace basically EVERYTHING on the darn thing or put another one in and rebuild the original one in my spare time??? I am not a total dummy when it comes to cars but I dont know everything, I do have lots of help from guys that love the old beater and want to help me get her to where she needs to be. Also if there is anyone in the Jacksonville Area that can give me a little more info on this old thing I would greatly appreciate it!! I sell cars, but high end ones... GERMAN autos... I know BMW M-B and Porsche but almost NOTHING about the old classics. hahaha I guess I'll be learning REAL QUICK AND SOON HUH?!?!?!?!

[cdowns]

welcome to the board// i wouldnt start thinking replacement till you've done whats required for a truck thats been sitting for a long time/changing fuel filter located in the carb where the gas line feeds itand cleaning gas tanks are 2 of the first things. then you start on the tune up new plugs and at a minimum cleaning and gapping the points i like to run new gas with a cleaner in it prior to thinking about takin the carb apart for a rebuild// change oil and filter and add a pint or so of marvel mystery oil in with it. a quick check for your plug wires is to run the engine at night with no lights if the wires are no good you'll see random sparking from them//also air filter needs to b changed and check all the vaccume lines for dry rot and cracking

[fine69]

Glad you found the board. I have sent you a private message, please check it.

Rebuilt carbs are cheap. And you can get them as most auto parts stores. Check your fuel filter. It may be clogged from sitting.

[El Jay]

First off; welcome aboard, to the board.

I'm pretty much with CDOWNS. Make sure the electricals are good. I'd add, when looking at the plug wires at night, use a spray bottle & mist the plug wires with water. If you have a voltage leak, that'll find it for sure; things will light up like a Christmas tree.
Put a can, or 2, of Sea Foam in the tank and then fill it. If it doesn't rum better after that, then look at pulling the carburetor.

Just my .02.

Good luck & once again; welcome to the board.

[67_C-30]

Welcome to the board! You've come to the right place. My '67 C-30 sat from 1990 until 2004 when I bought it, and it ran terrible when I first got it running. I changed the carb, fuel filter (numerous times - ended up replacing the fuel tank), fuel pump and did a good tune up on it, and I drove it 4 years until last year when I decided to the diesel in it. The original engine was still running, and I got 4 years of good service out of it. You can look at it this way, anything you put on it to see if you can get it running well can be put on a new engine as long as you plan on sticking to the same type engine.

[LinseyAnne]

CDOWNS _ I have done most if not all of that already...

New plugs, wires, New Dist. Cap & points, changed oil and put in Marvel first thing before anything, changed Valve cover gasket as it was leaking & needed to be cleaned pretty bad and I also broke off the old rubber oil cap off into the cover LOL oops! , Flushed Fuel lines out & changed filter, Fuel Tank is in good shape and wasn't nasty to clean out for added measure My buddy put some kind of coating for it inside - dont ask me I'm not sure what it was! - added sea foam to gas tank twice already, I cannot start the truck without using carb cleaner/starting fluid if it sits for more than 2 days. Air filter is new too... Trying to remember everything but YEAH I basically did ALL Of what you have stated already.

Today I noticed that the linkage has to be off or messed up somehow as I cannot go over 35mph at all. UGH!! I love it and hate it at the same time. Does it ever stop messing up long enough for me to fix one thing at a time?!?!?! LOL

[68C10HotRod]

Welcome to the board - you won't believe how much GREAT info the group here will provide!! Cdowns & 67_C30 gave you some good ideas & looks like you've already done most of them.

I'm pretty new here myself (1yr) & finally started working hard to make my '68 a DD too. Could only get mine to run initially by pouring gas down the carb manually. Tank was nasty, lines were totally clogged, new pump & finally had to tear down the carb. OMG it was nasty!!

Rebuilt the carb & got it back on the other day. Another thing I decided was chucking the points ign in favor of an HEI. This was real easy per the FAQ. The little 292 is purring & sounds very strong now that the timing is dialed in.

Be patient & stick with it cuz it will pay off at some point. These trucks are so simple to work on & fix that you really can't go wrong. My 11yr old can't wait to take our first drive.

[kwplot34]

My want to run a compression test on all the cyl's before putting to much money in other parts,if you have a weak or dead cyl it's time to stop and do a rebuild. A good compression test will also tell you the condition of the head too.

[68C15]

Originally Posted by kwplot34

My want to run a compression test on all the cyl's before putting to much money in other parts,if you have a weak or dead cyl it's time to stop and do a rebuild. A good compression test will also tell you the condition of the head too.

good idea but keep in mind an engine that has been sitting for a while can have low compression at first. then as it warms up and is driven it will smooth out and get better. having said that I would still do the test but only look for 1 or 2 dead holes with a significantly lower reading.

[LinseyAnne]

I label my mechanics by what they work on so when I say that my "american" mechanic took at look at her today when I got her started up to take down to his shop, its only 2 buildings over in my business park/storage center... That its not running on all cylinders and needs a rebuild. He's been helping me out here and there with things like the points...had no clue what to do there other than I knew where they went. LOL I read my breakdown manual everyday like a good little student. Today I changed spark plugs again because they are completely black and smell of nothing but fuel!!! uck! This truck completely smoked out my office today after I changed them. Ran it for just a little while and noticed that there are sparks coming from the back of the motor???? What in gods green earth?? I have no clue, I shut it off and parked it for the night. Today I had the same guy help me torch the bumper bolts off as they wouldn't come loose to save my life!! Bought a new Altenator and got it put on, easy enough. I love to play with it and all I really want now is a new bumper and headlights and for it to RUUUUUUUUUUUNNN!!!!!! LOL Thank you all for your advice and keep it coming cause a girl sure can use it!! Does anyone know anyone in the area that rebuilds?? Jacksonville/N/ Fl??? Sorry if I'm not allowed to ask in the forums, just curious.

[spinning wheels]

My 72 truck sat for approximatly six years, so I have gone thru a lot of the same problems that you are going thru.

The sparks in the back of the motor? Could be spark plug wires arching. If you haven't replaced them already. I would do that. Any brand at this point would be better than cracked old ones.

This could also be the one of the reasons your spark plugs fouled out. The old plug wires cause a weak spark.

The carburator would be another item I would have rebuilt or replaced as it may not be metering fuel properly.

Just replace or upgrade one item at a time, so you can trouble shoot it easier.

One other thing. How many miles on the truck or engine? It may not need rebuilding if it is a low milage engine. Food for thought.

Good luck.

[LinseyAnne]

Ohhhh Its got LOTS of miles!!! I couldn't really tell you but I'm guessing anywhere between 200-300k miles on her, she's lived a long hard life!! Shes pulled campers and been all over the US from the day she was bought by my grandfather. My mom always tells me how she used to ride in the bed and sleep back there sometimes. It had a topper originally but we trashed it when a limb fell through it. I have lots of the original stuff like the manuals, sticker, original title, warranty papers and lots of other things. My Pa took very good care of this truck but I truly believe that MOST of this truck is completely original, if it didn't break he didn't fix it. I am not touching it until I can have someone else look at it that wont just tell me it needs a rebuild... I get tired of guys who just want to take my money and do what they want and makes me appreciate those friends I do have that understand that I just need a little help diagnosing my problems not that I need them to fix it for me.

UPDATE!! OK I so put the NEW altenator on last night and its still not holding a charge, YES I charged the battery and ran the car for a while before giving up hope, still not holding the charge. So I'm guessing that I have a problem with something electrical... Can't be too hard to find as it barely has anything on it that requires POWER... right? ooo Does the radio stay on if you dont turn the knob off??? cause the radio doesnt work but I may have been playing around with it and made it come on or the lights... thats it right? couldn't be anything else there isn't anything else ... voltage reg was replaced already too... trying to think... I guess next I need to come up with the money for membership so I can buy a bumper, grille and hopefully someone has a carb for me thats decent. Theres a place here that does nothing but rebuild carbs but I'm looking at all my options.... Such a bargain shopper. Thanks for all your help!!

[PanelDeland]

Don't rule out the alternator or regulator yet.The parts stores buy the foriegn made stuff and it's not uncommon to get a bad one that's new.Charge the battery then put a test light between the ground post and the ground wire.If it lightss up you have a battery drain.Pull each fuse until the light goes off.This will tell you which circuit is draining the battery.Since you seem to be fairly new at electrical troubleshooting you will probably need help from this point.
You can also start the truck and check the voltage across the battery posts.You should be getting about 13-14.4 (approximately). volts while running and charging.

Maybe this will help you get started in the right direction.

[LinseyAnne]

Small update!!

Got the carb. rebuilt put on and she's not dumping fuel anymore!! YAY!! We ( I say we loosely) ran a compression test and cyl 2 has no compression what so ever. Guess I can't drive her on 5 cyl eh? lol Well she's in good hands now and is getting a much needed rebuild to get her street worthy, seems as though once you fix one thing another goes wrong so we're just going to keep on taking and giving her new things til she quits breaking. I swear that the bath I gave her washed away all the dirt and grease that was holding her together. LOL I am going to try and add a picture of her while I'm on today and you'll get to see my Orange Monster in all her beat up glory.

[*Dylan]

Ha, as dumb as it may sound I found out what was killing my battery. If you leave your key in your truck like I do with mine then make sure it's facing straight up and down in the ignition. I used to turn mine all the way to the left and later found out that was for accessories, I figured the same as you, there's really no accessories so nothings using power. If your battery keeps dying you can also check and make sure your ground cables are all getting a good connection.

[70cst]

with all the above! I wish I still had my Dad's truck. By the way... & from us to you. on getting your Grandfathers truck back. Looks like the start of a beautiful luv affair.

[big_al_71]

as usual alot of great advice and it seems like you are getting somwhere with it...Good luck and welcome from another Florida member....

[monte0185]

Sounds Like your on the right track. Just keep pluggin away and youll get her back in order eventually. I hope to have mine back together this weekend. Been working on painting motor stuff all week.

Oh and your comment on washing it. Thats the first thing my shop teacher in high school taught us. When you have an old motor like that NEVER wash it. All that grease and Grime is there for a reason. Its call natural stop leak and lubricant!! LMAO!! I cant tell you how true that is too!!

[BigDaddyDave]

Welcome to the board from NC!

[LinseyAnne]

LOL!! No I know better than to wash the motor. I hated to take the valve cover off when I did... But I had to I had broken the old rubber cap off into the cover, LOL ALOT of it into the cover. So of course I had to replace the gasket which took longer to scrape off than it did to put another one back on. BTW it did leak like crazy for about a week after replacing!! All I can say for the rest is TIME AND MONEY!! If you don't have either you can't get anywhere!