The saga continues - Sputtering, loss of power when accelerating

[Jmclendon]

So, apparently the plugs had fouled and the points needed adjusting. While there is a bit of sediment in the fuel, I'm told the tank is actually pretty clean.

Am I being unfair in thinking that if it was tuned less than 2 months ago and it hasn't been pushed real hard at all since then that I shouldn't be getting plugs which are fouling prematurely? I like the guy that's done most of the work. But, my gut is starting to tell me that maybe I'm getting taken for a ride. This last trip to the shop resulted in 11 hours of labour for the following:

Oil change (it was only changed 6 weeks ago. But, it had gotten dark pretty quickly)
Valve clearance adjustment
disassembly of distributor, clean and adjust points, lubricate advance weights
replace fuel sending unit
rework delivery pipe (the sending unit didn't quite align)
install a headlamp relay

I'm happy to pay what a job is worth, so if y'all think 11 hours is fair enough then I'll chalk it up as a lesson learned (IE, stop putting off buying the tools and shop manuals).

This dude is telling me that if it was him he would look at doing an engine rebuild in the next 6-12 months, as the engine is getting a bit noisy..... Again, it's all just starting to sound a bit over the top to me.

Anyway, the good news is I should be on the road again tomorrow.

[TJ's GMC]

Originally Posted by Jmclendon

So, apparently the plugs had fouled and the points needed adjusting. While there is a bit of sediment in the fuel, I'm told the tank is actually pretty clean.

Am I being unfair in thinking that if it was tuned less than 2 months ago and it hasn't been pushed real hard at all since then that I shouldn't be getting plugs which are fouling prematurely? I like the guy that's done most of the work. But, my gut is starting to tell me that maybe I'm getting taken for a ride. This last trip to the shop resulted in 11 hours of labour for the following:

Oil change (it was only changed 6 weeks ago. But, it had gotten dark pretty quickly)
Valve clearance adjustment
disassembly of distributor, clean and adjust points, lubricate advance weights
replace fuel sending unit
rework delivery pipe (the sending unit didn't quite align)
install a headlamp relay

I'm happy to pay what a job is worth, so if y'all think 11 hours is fair enough then I'll chalk it up as a lesson learned (IE, stop putting off buying the tools and shop manuals).

This dude is telling me that if it was him he would look at doing an engine rebuild in the next 6-12 months, as the engine is getting a bit noisy..... Again, it's all just starting to sound a bit over the top to me.

Anyway, the good news is I should be on the road again tomorrow.

11 hours? Really? This guy work on tonkas for a living or what? lol Rebuild the engine cause it's noisy huh....hmm...I guess he's never head of solid lifter cams. He did set the adjustment to .012 intake and .018 exhaust right?

[FetchMeAPepsi]

Originally Posted by Jmclendon

So, apparently the plugs had fouled and the points needed adjusting. While there is a bit of sediment in the fuel, I'm told the tank is actually pretty clean.

Am I being unfair in thinking that if it was tuned less than 2 months ago and it hasn't been pushed real hard at all since then that I shouldn't be getting plugs which are fouling prematurely? I like the guy that's done most of the work. But, my gut is starting to tell me that maybe I'm getting taken for a ride. This last trip to the shop resulted in 11 hours of labour for the following:

Oil change (it was only changed 6 weeks ago. But, it had gotten dark pretty quickly)
Valve clearance adjustment
disassembly of distributor, clean and adjust points, lubricate advance weights
replace fuel sending unit
rework delivery pipe (the sending unit didn't quite align)
install a headlamp relay

I'm happy to pay what a job is worth, so if y'all think 11 hours is fair enough then I'll chalk it up as a lesson learned (IE, stop putting off buying the tools and shop manuals).

This dude is telling me that if it was him he would look at doing an engine rebuild in the next 6-12 months, as the engine is getting a bit noisy..... Again, it's all just starting to sound a bit over the top to me.

Anyway, the good news is I should be on the road again tomorrow.

If it took him 11 hours to do all that he was working in the dark after killing a keg. No way!


First rule of 6066 GMC Club - Don't talk about 6066 GMC Club! Ok, that's not really it, but the first rule should be "Don't let anyone work on your truck but YOU."

Too many times we've seen great iron be mistreated by ignorant (though sometimes well meaning) mechanics that have zero experience with a car that doesn't run on a computer.

If you're going to run an old truck you *NEED* to buy a manual and you need to be willing to get your hands dirty. It's just a necessity, but it's a good one. You'll learn valuable skills while tinkering with your baby and you'll grow closer to the historical genius engineering that made these engines. There's nothing like them, even today.

You don't need a ton of tools either. You can do most work on these trucks with a standard socket set (not metric), a couple of screwdrivers, and a set of wrenches, again standard. So for $60.00 you're all set to start fiddling!

The point is that you can't trust anyone with your truck. Only you.

[Jmclendon]

I certainly agree for the most part that I want to get to a point where I'm doing the majority of the work. But, at the end up the day facts are facts. If the vehicle is getting work done in a garage that specializes in vintage cars then I'm going to feel more confident about the outcome than what I would if I was to attempt to do it myself. Particularly when you consider the fact that at the moment I've got a socket set and pretty much nothing else.

At the end of the day, I'm just not the type of person who is going to feel like I'm somehow less of a guy simply because I'm willing to defer to someone that knows more about something than what I do. In fact, that's half the reason why I don't have a problem asking what's possibly seen as stupid questions in this forum. This is all a process that I've only just started. Personally, I think things like

Rebuild the engine cause it's noisy huh....hmm...I guess he's never head of solid lifter cams.

comes across like the type of know it all bragging that I just don't think helps anyone. For example, even I know that there are a lot of reasons why an engine might be making more noise than it should. It seems pretty reasonable to think that a vehicle that is close to 60 years old might have a bit of piston slap going on.

If that's the case, why not look at doing a full rebuild? If the idea is for it to be the best than it can be and you've already committed to having the engine out, wouldn't it make sense to do it all while you're at it? I think so, others might not but that's ok.

Anyway, I guess my point (as this has gone off topic a bit) is that if my dog has a scratch, I'll take care of it myself. But, it's got a broken leg, I'm going to take it to a vet. Same idea. I'll do the work that I'm comfortable and capable of doing, and I hope with time that covers more than it does at the moment. But in the meantime, I'm not going to get my feelings hurt simply because a mechanic or an auto electrician or whoever knows more about this than what I do. That's why they're getting paid to fix cars and I'm getting paid to do what I'm doing. That's also why I come here, because there's loads of people that know more about this.

[FetchMeAPepsi]

Originally Posted by Jmclendon

I certainly agree for the most part that I want to get to a point where I'm doing the majority of the work. But, at the end up the day facts are facts. If the vehicle is getting work done in a garage that specializes in vintage cars then I'm going to feel more confident about the outcome than what I would if I was to attempt to do it myself. Particularly when you consider the fact that at the moment I've got a socket set and pretty much nothing else.

At the end of the day, I'm just not the type of person who is going to feel like I'm somehow less of a guy simply because I'm willing to defer to someone that knows more about something than what I do. In fact, that's half the reason why I don't have a problem asking what's possibly seen as stupid questions in this forum. This is all a process that I've only just started. Personally, I think things like comes across like the type of know it all bragging that I just don't think helps anyone. For example, even I know that there are a lot of reasons why an engine might be making more noise than it should. It seems pretty reasonable to think that a vehicle that is close to 60 years old might have a bit of piston slap going on.

If that's the case, why not look at doing a full rebuild? If the idea is for it to be the best than it can be and you've already committed to having the engine out, wouldn't it make sense to do it all while you're at it? I think so, others might not but that's ok.

Anyway, I guess my point (as this has gone off topic a bit) is that if my dog has a scratch, I'll take care of it myself. But, it's got a broken leg, I'm going to take it to a vet. Same idea. I'll do the work that I'm comfortable and capable of doing, and I hope with time that covers more than it does at the moment. But in the meantime, I'm not going to get my feelings hurt simply because a mechanic or an auto electrician or whoever knows more about this than what I do. That's why they're getting paid to fix cars and I'm getting paid to do what I'm doing. That's also why I come here, because there's loads of people that know more about this.

On one hand you asked if you should buy a manual and learn. Then you turn around and say you're "not less of a man" for not doing the work yourself...I don't get where you think we're saying you have to "be a man" and growl at it while you eat a raw turkey leg.

What we're saying is your mechanic is stealing your money and you should'nt have your entire engine rebuilt just because his rent bill is due. It's up to you, dude. It's your truck and it's your money. Just don't ask if you don't want an answer. I don't have anything else to say on the subject.

[Jmclendon]

Truth be told, I think the lesson here is I shouldn't communicate with the outside world when I'm at work. LOL I'm never the best version of myself when I'm in this place.

No offense was meant. I've just gotten prickly about it for no good reason.

Thanks again

[Funky61]

It's tough to read intent or emotion on these forums sometimes.

But having read a lot of posts from TJ and Fletch; I find them both to be pretty funny (Fletch) and resourceful guys (TJ-LOL-tongue-in-cheek), in their own unique ways. I've never met them so I can only go by what I read and my gut feel about them which is; very Positive and always helpful.

I detect some contradictions in your posts and nowhere did I read that someone questioned your manhood.

-But, my gut is starting to tell me that maybe I'm getting taken for a ride,
-This dude is telling me that if it was him he would look at doing an engine rebuild in the next 6-12 months, as the engine is getting a bit noisy..... Again, it's all just starting to sound a bit over the top to me.
…I'm happy to pay what a job is worth, so if y'all think 11 hours is fair enough then I'll chalk it up as a lesson learned (IE, stop putting off buying the tools and shop manuals)

-That's also why I come here, because there's loads of people that know more about this

In my opinion:
The question/concern put forth by you was answered in a "tone" that I've always picked up from TJ and Fletch. You mentioned some terms like piston slap which tells me you know something more then a guy that just has a crescent wrench set.
That's probably why you came here to get confirmation and I think you got it.

Does not doing any work on your car/truck make you less of a man? Of course the answer is NO, but it helps to have the manual and read up on the areas you are having worked on, so you could ask the mechanic about the valve adjustment specs etc...etc.

It's great that you'll have your truck back on the road but...

I would trust your gut on this; but not with the raw turkey leg. but I digest...I mean I digress LOL

[TJ's GMC]

My post was taken completely wrong. lol Sometimes it's hard to tell a person's attitude through a key board.
The 1st red flag for me was it took 11 hours to do basically an engine service and some other minor work. I service my 305 in about an hour. So, 10 more to do some other stuff.......hmm....

2nd red flag, Why did he do All that work just to tell you it's gonna need a rebuild in 6 months? Unless your driving the truck EVERY day, 6 months worth of miles is really not that much. I drive mine 7 days a week so the miles add up quickly.

Also, there are Plenty Vintage Car Guys/Garages that have never even Seen a GMC V6. I've seen plenty on Youtube that always say, "First time I've seen one!" That's why I said...He probably has never heard of a solid lifter cam because these engines are Supposed to have valve tapping noise(Assuming that's the noise he's referring to, which I should have mentioned.) That's one easy way you know the valves aren't to tight. lol Thing is, the valve train is noisy enough that sometimes you may not even Hear a slight knock in the motor. Mine had a slight throw out bearing knock only hearable from inside the cab, in the bay you could only hear loose and happy rocker arms.

I understand your irritations. And know that none of us are Downing you in any way because you are trying to do your truck the right way even if it means having someone else do it. We just don't want to see you get ripped off. It's an unfortunate thing that a lot of shops do it now a days.

[jimjaz]

Just a thought, and my 2-cents...
Oftentimes when a problem pops up, it is very likely that the most recent change to hardware or other maintenance makes the problem appear in the first place, so going back to what was last done may be the issue.
You mentioned you are using an electric fuel pump- is this recent? Do you have a fuel pressure gauge (gauge AND regulator is better) to actually see what the fuel pressure in the line actually is? Fuel delivery pressure is important, and not all electric fuel pumps are created equally- some are quite poor in their basic job of a steady pressure and fuel delivery.
Has your mechanical fuel pump been removed from the engine, or is it still in place? If still in place, is your fuel line still connected inline or has it been bypassed?
Do you currently have a fuel filter on the pickup tube in the tank? You mention some "stuff" in the carb pre-filter- it's coming from somewhere upstream, most likely the tank.
If the innards of your tank is at issue (most 50 year old tanks should probably be replaced), then I would suggest this as a thought to pursue. Check out http://www.tanksinc.com/index.cfm/pa...rod/prd404.htm

Anyone out there who has "dressed up" their fuel delivery lines with the fancy (and $10.00 a foot expensive) should think really hard about removing it and hard-plumb it. It is nothing more than cheap rubber hose made in China that is covered in the braided stainless, and is not even compatible with gasoline for long periods, and I am a testament to this fact... I was backing my 55 Chevy out of the garage recently, and smelled raw gas- found a huge puddle under the engine, and it was soaked. Fancy SS covered fuel line has split. Can you say FIRE? Well, there wasn't one, but there easily could have been.
Not to worry- NAPA has some hard line that is very malleable, because it contains some copper, it is easily bent, lasts forever, and is nice to look at with a very subdued gold look to it.
RUBBER FUEL LINE is just fine to use, just not the junk that is masked with the braided stainless mesh, at least the stuff that I had under my hood at the time. It just needs to be stamped as "fuel line", because that is what it is made for.

[kchampagne]

Before spending any more money at the shop, I would have a compression test done. You really shouldn't have to change the oil after 6 months unless you've put some serious miles on the road. I surmise that you have some bad piston rings. This could be the culprit for the dark oil and fouled plugs. If you have bad compression, then you are up for a rebuild. If that is the case, you will now have a big decision to make. You will need to decide whether you are "all in" on the 305 or go another route such as swapping it out with a SBC for example. Getting the 305 rebuilt is going to be quite the challenge: both finding parts and finding someone you can trust to do it. Rebuild parts are extremely hard to find, and if your crank, cam, and/or pistons are shot, the task is even harder. I don't think anyone makes cranks, cams or main crank bearings anymore, so you will be looking to find NOS. Rebuilding the 305 will probably be much more money than swapping a SBC. But, I assume you are here at this 6066 forum because you believe there is something really cool about the GMC big block V6's. That is why we all are here!!! Finding a used 305 is also a recommendation.

Now if your compression is okay, I would replace the entire fuel system. Everything. Until the bad gas and sludge is completely removed from the entire system, you will never solve the problems.

If you are still fouling plugs, you can move on to the carb, timing and distributor.

This process should narrow down your issues. And, I agree with everyone, that 11 hours is way too much to spend before determining if the engine compression is good enough to begin with. It could be that the mechanic spent 7 hours of the 11 reading up on the GMC manual on how to fix things.

I hope this helps!