power loss, burning, lack of fuel...wtf??

Two steps up in jet size is plenty at one time. I'd log some more miles and burned tanks to see how it does. The main objective with your primary jets is to make sure that you aren't experiencing any lean surges at cruising speed. I'm talking about no load on flat ground at @ 50 mph...just rolling on a Sunday drive. As long as you're not getting any intermittent fuel starvation feedback under those conditions, your jets are big enough. Its easy to over jet and turn the thing into a pig Rich, carbon-barfer. You think your mileage is bad now. Reading spark plugs with today's corn skweezin joos is kind of an art form. Aside form a real obvious issue like oil or fuel fouling, anything that is in the general realm of normalcy tends to be a bit subjective. I was told several years back that the reading should be done immediately after a period of easy cruising like I described above. In other words, you're cruising along in a driving miss daisy fashion between 40 and 50 mph, when along comes a nice pull off spot where you can cut the engine at cruise speed and coast on over to a stop. That's when you check your plugs. Not after it's been idling in your driveway for a half hour.

The cam was slightly adjusted as well. Huh? Please explain.

You probably only scratched the surface of the total amount of chupacabra excrement inside your coolant passages. It can get truly gross, congealed and coagulated on an old rig that hasn't been properly maintained over the years. Not what you wanted to hear I'm sure, but we aren't in the habit of blowin' sweet nuthin's up peoples' skirts around here.

I forget if this has been asked and answered before, but is your choke functional on this carb?

Wanting to shift at a higher rpm? I'll say it again. Huh? No, that doesn't make any sense. Its a manual transmission. What it "wants" or doesn't want is irrelevant. You're the captain of the ship. You tell it when to shift based on a variety of conditions.

A stuck vac advance is no good. You need to get that fixed. Performance and fuel economy will be adversely affected until you do.

I could go into my patented speech about fuel mileage computing, accuracy of instruments, scientific controls, driving habits...yadda, badda, do-da...but I think I'll hold off until you report that your vac advance is functional.
 
Well, I guess the thinking was to up the jets to counter the lean. I pulled one after a good 25 mile run mostly highway. I'm at sea level in los angeles by the way. The cam was moved over I think about 1/10 inch if I'm not mistaken. I didn't watch...as far as the crud inside it was a punch in the gut for sure....were gonna flush in a few months...any suggestions on a new distributor? When the cap is off the plate wouldn't move and didn't effect the engine. As always you can tell I'm quite the expert lol and appreciate the info as I'm absorbing as much as possible!!
 
A rebuillt distributor can be bought in the store here. It won't have the tac drive or governor stuff though. Is that important to you?
 
I don't think so...we think that was all stripped off the carb anyway...
Honestly I don't even know what you mean by tac drive...
 
Oh, that's an easy one lol. I have a tach now and like having it. Oh and what I meant by shifting at different times was that she seems to be running more smoothly up to 3500 when she seemed to be asking for a shift at 3000 before...
 
I don't think you've necessarily done anything wrong by going up to 53's. The ethanol does tend to be a bit on the lean side. I'd hold off on any further jet changes until your other known issues are resolved.
 
Thanx scoutboy, that's somewhat relieving! So I think my main issue now is getting a new distributor. Is there a plug and play one? I have pertronix and the carb is stripped of the governor and dash pot. Its the old 2300 model. Any other info needed to decide? Im getting 7 mpg with all of this cleaning, new plugs and tuning....I was getting 10 before! This is killing me :confused:
thanx!
 
Loadstar stuff is rare. The best bet would be to have yours rebuilt. Or go to the IH dealer and see what they can come up with, but be prepared to spend some big $. The ones here will work,but won't have the correct advance curve for a big truck a d no tac drive.
 
Good thing this isn't a loadstar. I think chappie meant to post to a different thread. Blastruck, you can probably have your present distributor rebuilt. There are places that do that. I don't know the business names. We haven't id'd your distributor model yet and we should. Most likely its a Holley, but that can be confirmed with some pics with the cap on and off. It might just be that the diaphragm inside your vac advance canister is perforated and unable to hold vacuum. That's easy to test. You need to unhook the metal advance line and then apply a vacuum to the fitting on the canister. This can be done with a mityvac tool, or even by sucking on it with your mouth. Probably need to remove the canister from the distributor body to do this. With vacuum applied, quickly place a finger over the fitting hole and watch the advance arm. It should stay in place as long as you have the hole covered. If it moves, the diaphragm is shot. IHPA has rebuilt canisters for the Holley distributors. They ain't cheap, but less cabbage than a new distributor. They also sell reman Holley distributors. If money is no object, you could even go the davis unified ignition (dui) route which is the general motors hei design modified to fit ihc engines. If you have to ask how much it costs, then it might not be for you.
 
Ok guys. Did a 120 mile round tripper into the "mountains" last nite and its the strangest thing..some hills, I'd be in 4th and she would just give up, rpms dropped engine speed fell to like 30 mph and I'd have to drop back into 3rd....other hills, shed pull in 4th at 55+ and I'd have to take my foot off the gas to slow down. No rhyme or reason....its almost lime there was a turbo on sometimes. What would cause this sporadic power difference!!?? The only thing I was thinking and noticing is that she was better with the pedal only about 1/4 pressed, if it was floored she would die off...could the carb be flooding? Float off? Too much gas in the bowl? Hidden invisible super charger? Lol
 
Malfunctioning vacuum advance, incorrect fuel level in bowl, accelerator pump linkage out of adjustment, blown power valve. Those are the leading suspects. In broader terms, you have distributor and carb issues. No real news flash there.
 
It's not Rich I guarantee it.

I'm tellin ya that you need to do that same run again with a fuel pressure gauge hooked up so you can see it while driving. Betting that while it loses power the fuel pressure is low or nil.
If not it is float

I'll read back and see what carb you have but you are describing the symptoms of fuel starvation perfectly.

Have you correctly set the float drop? If the float can not drop enough the fuel valve will not allow enough flow. I have seen and diagnosed a float that was hanging up and not being able to drop enough while under high loads doing just what yours was. Some times it would be fine others depending on vehicle attitude, would fail and bog.

Another is the off road fuel inlet valve with the spring loaded pin tip. If you set the float with the pin tip compressed it will fail to give enough fuel to properly fill the bowl.

This is a reponce to the op's last two posts cuz I type slower than sb74. :lol:
 
Robert! I think that makes the most sense as well but we looked at everything during the rebuild and he says he didn't see anything... I'll discuss again tonight with him. Also, don't you think it would do that without the trailer as well? I'm still questioning if the brakes on the trailer are grabbing too...the manufacturer says no but it would make sense, especially when I can't gain speed on downhill every once in a while....:incazzato:
 
The trailer is a variable that can only contribute to the speculation right now. I know you need to tow it frequently. If you could log some miles without it, that would eliminate a huge variable. That's what you need since this truck is just one big variable itself. I would think though, if you suspected the trailer brakes were dragging intermittently, that would be easy enough to heat check and smell check if you had the time to pull over for a tlc. That's tire load check for the non-gear jammers. If the brakes feel and smell hot and you ain't been usin' 'em, that orta make a fuller go "huh"?
 
Yeah, she's definitely a mystery on every turn lol were gonna pull the distributer tonight and see what's up with the vacuum advance and hopefully fix. I drive a decent amount without the trailer and there's no issue like when the trailer is on. I'll give an update after tonights session. Funny how I actually want to find something wrong so there's an answer but everything winds up being fine lol.
 
blasttruck said:
Robert! I think that makes the most sense as well but we looked at everything during the rebuild and he says he didn't see anything... I'll discuss again tonight with him. Also, don't you think it would do that without the trailer as well? I'm still questioning if the brakes on the trailer are grabbing too...the manufacturer says no but it would make sense, especially when I can't gain speed on downhill every once in a while....:incazzato:
Click to expand...

Very possible, because pulling a heavy load like the trailer, the fuel demands are higher, heat is higher.

Without fuel pressure data it is really pure speculation. Good fuel pressure under the same high demand situations then you can definitively cross that off the list.

If you were simply experiencing a high drag situation and you would have to down shift, before the down shift, your engine would still be running and sounding similar but slower like lugging down. If that's the case then you're looking at something other than fuel. Fuel starvation would be stumble and stop running.

Seems like every phase of your problem brings out new information.
Are you running the stock carb?
 
So, here's the latest...I posted before but don't see it.
The carb was definitely governed and is under 300 cfm...maybe a 297. The vacuum canister was full of gas. Took out the distributor, cleaned the outside, poured the gas out and it worked on a hand held vacuum gauge. Turns out it must have been flooding the whole time, so in 4th uphill when I was deep on the pedal it May have been flooding. When we checked the carb, there was no vacuum, so I don't think the advance was working after all that. Tried to t off the manifold vacuum but then my power brakes went out. Tomorrow we check the tang since lowering the float wasn't enough and check for blockage in the carb that May be stopping the vacuum. Love to hear any other thoughts you guys May have, and hoping this mystery is put to rest after this!!
Oh, and the fuel pressure was around 5 psi if I'm remembering correctly..
 
The vacuum advance attached to the distributor was full of gas???:yikes: I've never heard of that happening. What's this "tang" that you're checking? The kind that allan sheppard mixed with his vodka while in earth's orbit? Or the kind that makes blood rush from the big head to the little 'un?:ciappa:
 
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