The 300 has very strong torque and I wouldn't exactly call 1600 rpm "lugging".

 

I didn't exactly call 1600 rpms lugging.

I said that it had to work harder to turn the gears over at those RPMs, which in turn used more gas. I didn't say it struggled to do it.

 

Thanks guys, Ill look into it. I was cruising down the highway today and the truck kept dying on me. If I turned the key off, then back on, itd go a little further then start to go out again. A little quick diagnosis says the coil may be out. Once I get that fixed, Im going to take another look at my timing.

Ive always had timing issues on this thing. That seems to have been the problem from the start. The distributor was off time, 180 degrees out, and it wouldnt run. So maybe that is contributing to my high RPM. I have good power to it, though.

Another question. When I go about 60-70 and take certain curves on the bypass, the trucks RPMs will drop off all of a sudden, then the truck will roar back to life, then lose power, then roar again. This goes off and on until the road straightens back out. What may cause this?

 

My first thought is that your power steering pump is SHOT and is draining a butt-load of power when it needs to assist your steering. But that's just a guess from the symptoms.

 

"The 300 has very strong torque and I wouldn't exactly call 1600 rpm "lugging".

Well,...maybe.

1) when the engine cannot be accelerated by applying full throttle and/or

2) When the pyrometer and coolant/oil temperatures were rising and oil pressure was less than normal for the revs

Those are the principles for big-truck operation and at what point lugging may occur and down shifting is necessary. The variables are infinite and there is no way one can actually come up with a specific RPM that is definitive for determining 'lugging' or what RPM is best for MPG.

 

I thought about that, but the engine doesnt even attempt to die when it is sitting still and I turn the wheel, or at slower speeds. Im not disputing you, just clarifying that this ONLY happens at ~65 miles on a certain turn or two. If I can do it safely, tomorrow I will video what it does as I take the turn.

 

Oh no worries, was just popping out ideas to see if maybe one stuck.
Mostly because it only happens while you're turning. Unless you're turning SO FAST that the gas sloshes to one side of the carb and starves the engine .

Seriously though, that is a strange symptom. I'll try and think of what else would cause that. However, if you're really wanting help, I'd suggest starting a new thread.

 

Are you having to apply the brakes while taking the "certain curves"? Perhaps the master cylinder has a vacuum leak?

 

No, not at all. That is a good point though.

 

Boy, if it was mine with those symptoms, I'd check fuel pressure.
If you can, get a gauge on it while you make the truck bog down in corners.
Probably it's ok, but if there's junk sloshing around in the tank,
that MIGHT do it.

It also rules it out as a source of problems in general...

hth

t

 

sounds more like fuel starvation to me. Root cause - who knows? The suggestion about checking fuel pressure is a great one; also how full is the tank when this is happening? Or - had a friend who had crap in his tank and when he floored it, sucked up crap which plugged the pick-up screen - when he backed off it pulled fuel normally. Lots of things can cause this. Could also be something like a bad ground at a point where going around the curve pulls on the ground strap funny or pulls a poorly grounded component loose. Just m $.02.

 

sorry for resurrecting a zombie thread, my bookmark was set for the last page read instead of the first page.