6066 (1960-1966) GMC Truck Club - Help for a new guy

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- I-6 Engines (https://6066gmcclub.com/forumdisplay.php?f=17)

- - Help for a new guy (https://6066gmcclub.com/showthread.php?t=47728)

Re: Help for a new guy

Quote:

Originally Posted by Vernski (Post 50898)

Sounds just like a clogged fuel filter, replace the one inside the carb if you have already cleaned it it may still have shellac in it..Vernski:poke:

Yea, I'm wondering if I didn't get all the gunk out of the carb with the rebuild.

Re: Help for a new guy

Quote:

Originally Posted by WDShaffer (Post 50904)

Agree with all that advice - sitting still isn't good for us or our trucks. Engine either fuel starved, or you have a leaky intake gasket leaning up the mix. Easy way to eliminate a leaky gasket is with a can of starter fluid. Get the engine idling smooth and slow. Spray the starter fluid in short bursts at each side of the base of carb, and wait between shots. Follow this procedure around each port. If idle doesn't change, no leak and proceed with fuel delivery troubleshooting.

I've had to deal with plugged accelorator jets too; like Vernski said, fuel starvation for 1 reason or another.

That's a great idea, I'll try it this weekend. I was wondering about a vacuum leak or something similar. The only thing that makes me wonder is that the truck had the same problem when I got it; but I chalked it up to the fuel system being so fouled. Or I replaced the gasket on the accelerator pump, but remember thinking that the well it sat in looked really pitted. I found it hard to believe that it would work well (an earlier poster wondered about something similar).

Re: Help for a new guy

Quote:

Originally Posted by FetchMeAPepsi (Post 50890)

IDK about the I6, but the V6 only has a couple of marks for timing. If you set it 3-4 marks on that motor you'd be at like...+15 on timing:ahhhh:

Are you sure that's right?

I've been scratching my head trying to figure out, between web advice and books, what timing mark it should be set at. After reading your post, I think I forgot to plug the vacuum advance...back to the drawing board again.!

Re: Help for a new guy

Quote:

Originally Posted by Vern (Post 50907)

Yea, I'm wondering if I didn't get all the gunk out of the carb with the rebuild.

If you didnt soak it overnight in carb cleaner you didnt get all the gunk out.

I'd pull it off an redo it. Soak everything! its the best 15.00 you'll ever spend.

Re: Help for a new guy

Quote:

Originally Posted by GMCDAC (Post 50789)

Don't think I have helped much here and this is probably not the problem either, but it happened to me when I built my Rochester M the first time. I bought 3 disassembled Rochesters, 1 model M (manual choke) and 2 MV's (automatic choke) parts carbs to build one good one and the plan went fine, as I wanted the Model M. It ran rough but idled pretty good. Since all 3 carbs were completely disassembled I had put the metering rod spring under the power piston arm instead of on the top. The drawings in the kit instructions did not show the spring position, so it was a guess.

The pic is of one of my parts carbs and how the spring should be positioned.

Later---DAC

OK, thanks! I just installed it wrong.

Re: Help for a new guy

Quote:

Originally Posted by Vern (Post 51014)

OK, thanks! I just installed it wrong.

You're welcome---DAC

Re: Help for a new guy

I rebuilt the carb again with a kit from Mike's carburetor parts, who have some nice youtube videos showing how to do it. I soaked it overnight in a bucket of cleaner first. Today I was able to drive it 50 MPH without the choke pulled out. Won't be winning drag races anytime soon, but runs much better. Thanks for all the help folks!

Re: Help for a new guy

Vern, what makes you think your truck does not have a stock 250 inline 6. 66 was the first year that the 1000 had a inline 6 available, it could come with a 230 or a 250 or a 292.......????Kieth :woo:

Re: Help for a new guy

The guy I bought it from didn't know much about the engine, but did say it wasn't original. Based on the casting number, it's a 235 or 250 chevy /oldsmobile between '67 and 71. Looking at the number behind the distributor, I think it's a 250... but will get a better look at the pistons when I take the head off.