IP/HH/fuel setting/starting questions

[DavidWymore]

New filters, adjusted valves, 70 runs better but not 100%. My LDS in my '62 starts with a bang on one or two rotations with no throttle.The 70 spins a bit and slowly catches unless I floor it. If I don't, it idles slow, like 500 until I bring it up, then it stays about 800. I noticed the shutoff rod points straight down, 6 o'clock. I think from reading here it should be more forward, 7 o'clock. Does the main fuel setting affect this? Also...if I get the truck rolling and idle along put it in N and then bump the brakes to a stop, the engine chugs and RPMs drop. Why would the sharp stop affect it? Something in the governor, the weights?


I'm going to try turning up the fuel tomorrow.

 

[DavidWymore]

I turned up the main fuel setting a thread or so (more when gauges arrive) , it helped the starting some, which makes sense after reading a post by Floridianson stating that with the engine off, the shutoff goes to full fuel. What's strange is that if I floor the accel pedal, it starts faster and with more authority. This lead another member to suggest backing off the droop screw, theory being that it gives the governor more room to work below 1600 RPM IIRC. I backed it off some and it seemed to help as well.

Still curious what controls the location of the shutoff rod, and why coming to and abrupt start causes a "slosh bog". If I set the parking brake with clutch in/trans in N, and the truck just barely rolling, the truck rolls back and forth from the windup in the drivetrain and suspension, and the engine idle bogs a big with each slosh/bounce/direction change.

 

[gimpyrobb]

If the truck has not been run much, I would say gummed up fuel or varnish in the system. Another member had rpm issues while braking and he reported the fix had something to do with the governor. Does it "hunt" rpm at all? I've had luck using SeaFoam to help clean up and stabilize the fuel system.

 

[Katavic918]

......

 

[Floridianson]

Don't mess with the droop. When the throttle peddle is applied it does allow the fuel control to go just a tad bit farther than if it was not applied. Yes back off the outer nut just a tad and mark the inner nut with a black marker and turn it up half a turn after. Then test. If you get a pyro then you could do even more and the truck will wake up. After you put on the pyro and we do main then you will go back and do droop so as you don't waist too much fuel between 1600 and 2000 rpm.
The main fuel double nuts move the wedge plate and that is where the fuel control assembely gets it orders as to how far it can go. Yes start with bumping up the main ( twin nuts) and see if that does not fix the other problem. From what it sounds your truck is sleeping and we need to wake it up.
Also need to bypass FDC too if you have not done so as that would increase the main fuel and you might have to back down on the main and then adjust the droop.

 

[DavidWymore]

I should note...the '62 is an LDS engine with an LD pump. I know it's not a precise indication, but 7 threads showing on the main. I believe it's still safety wired. Not roadworthy, smokes pretty good though.

The '70 I'm trying to get to wake up had 3 threads showing, I bumped to 4 and will add more when I get gauges installed...after I get a trans built.

I previously went through this with my other yard beater. An LD pump non turbo '66 that didn't smoke and had no booster pump or power. I put a 30psi elec pump on it and turned it up to 7 threads. Helped considerably.

 

[DavidWymore]

If you skip to the end of the '66 thread in my sig, there are pics, etc. of that go-around.

 

[Floridianson]

Yea we don't want to get them too hot and without a pyro play it safe. When you do get it we will have you drifting around the dirt street corners and kicking up the dust. You might have backed down the fuel from 1600 to 2000 rpm range by backing off the droop. Not a problem to get it all tweeked back. By backing off the droop it increased the main just a tad but lost the lower range fuel just a tad.

 

[DavidWymore]

Got a pyro rigged up off the 2nd batt, the one with neg to ground. Made 800 degrees max on flat ground hogging on it in 4th and 5th. Went 22 flats, bout 7 threads showing, woke the old girl up nicely. Starts with a bang and a puff of smoke like the '62, smokes medium when accelerating. Can feel the acceleration now, not just lots of noise and a barely creeping up speedometer. Still doesn't hit 1200, is there more to be had? Or where is the point of diminishing returns, excessive smoke, and shortened engine lifespan?

Much obliged.

 

[gimpyrobb]

Nope, crank away. I run mine up to 1200 often.

 

[DavidWymore]

Nope, crank away. I run mine up to 1200 often.

Used to peg my cummins at 1600 for short bursts. It didn't last...


At what point does the adjustment bolt twist off?

 

[DavidWymore]

Turned it up til the nut stopped. 1200 climbing an overpass in 5th, haha. Sure do like it, I can keep up with traffic from stoplights around town now without flooring it, winding it out, and shifting as fast as possible.

 

[DavidWymore]

WARNING! DO NOT install your pyrometer probe in the existing hole in the rear of the manifold! It will give you a significantly low false temp reading, making you think it's not as hot as it is and possibly melting your pistons!

 

[Jeepsinker]

You turned your main fuel up as far as it would go?

 

[DavidWymore]

Yes, but had the probe in the wrong location originally. Gets warm quick, will be turning it down, but I'm used to babysitting a pyro. It's hard to do in the dunes though.

 

[Jeepsinker]

Ok. I was going to say, sounds like you're asking for problems...