1968 Mercury 250 Camper Special

[Bullitt74]

Better to find those leaky brake lines now...

Looking forward to seeing your painting skills on that box!

[cdnwillyg]

You and me both Steve! The box still needs a little TLC before paint though.
I actually fired up the truck from inside the cab yesterday and that was a good feeling. I now have to see why the power steering is feeling like manual because it wasn't working...??? All the gauges are working correctly but the alternator gauge was on full charge so I checked the voltage at the battery and it was 14.2 volts, telling me my alternator was working. But I thought the gauge would should be reading center in this case or am I out to lunch in my thinking? I believe the gauge is wired output of battery against that of the alternator, so if the two are the same it should be centered on the gauge, yes/no?? Or is the regulator at fault here?

[hdman90]

You and me both Steve! The box still needs a little TLC before paint though.
I actually fired up the truck from inside the cab yesterday and that was a good feeling. I now have to see why the power steering is feeling like manual because it wasn't working...??? All the gauges are working correctly but the alternator gauge was on full charge so I checked the voltage at the battery and it was 14.2 volts, telling me my alternator was working. But I thought the gauge would should be reading center in this case or am I out to lunch in my thinking? I believe the gauge is wired output of battery against that of the alternator, so if the two are the same it should be centered on the gauge, yes/no?? Or is the regulator at fault here?

Gauge should read in the center when the alternator is working! You are correct in your thinking!

[cdnwillyg]

Well I started the truck this morning and the alternator gauge was almost dead center, so not sure what happened there. I also got lucky with the power steering by just adding more ATF and it starting working as well, I guess once the pump was turned by the engine it filled the system and lowered the level in the reservoir, so nice easy fix there too!

[cdnwillyg]

Okay I need some help on this engine tune I'm trying to do.
Just to refresh, I have a 390 FE, Holley 4150 570 CFM, MSD ignition and long tube headers. I'm assuming engine was just rebuilt to stock, not sure. Compression 190-195 across all 8 cylinders(according to my compression gauge??)
So here is where I'm at: timing at 10* BTDC, idle at around 750-800 rpm. carb. set up as per Holley instructions. So it starts good with a couple pumps on the gas peddle runs okay, but when I shut it off there is a little run on for about 2-3 seconds. With my vacuum gauge on the manifold port it reads about 12-14". If I pick up the idle it drops down as it should, and if I give it a slight punch on the accelerate it will return the vacuum to 16-18" then slowly fall to the 12-14". I don't notice any hesitation when I rev it or have high rpm and punch the accelerator , the response seems great. Now I am using 87 octane gas, is this a cause of the run on??? This is all under no load, stationary vehicle.
So any ideas would be greatly appreciated.

[DuckRyder]

Are the secondaries completely closed at base idle?

[cdnwillyg]

I believe they are and I don't see any adjustment there if the weren't. The only way for me to check when running is by using a small screw driver and feeling if there is any movement. I should also mention this is a new carb with maybe only an hour or two run time.

[DuckRyder]

What is the list number of the carb and does it have an MSD distributor as well?

There should be a secondary air gap adjustment accessible from the bottom of the base plate.

It has been a while since I messed with this, but on mine anything much above 650 RPM has the transfer slots uncovered in the primary at idle, 650 is to low of course. So options are: 1) live with run on, 2) open secondary slightly so that the primary can be closed down, 3) EFI. at least that is how I remember it.

[cdnwillyg]

The list number is 80570 and yes I am running MSD distributor. I will try lowering the idle and see if that at least stops the run on if transfer slots are open. It does seem to be running a little rich, would adjusting idle mixture screws be an answer?

[DuckRyder]

Allright, a 570 Street Avenger, good carb.

The MSD distributor should have come with a blue bushing and 2 heavy silver springs installed. This gives you 21 degrees advance that comes in by about 4400 so with your 10 degrees initial you only have 31 total.

Guess you got to be a little careful not knowing the compression, but I would probably turn the initial up to about 15 and see if it would let me close the air gap on warm idle down...

I’m assuming the choke and fast idle is working properly. (This might be a good one to cross post to engine too)

[cdnwillyg]

Yes the choke and fast idle seem to work just fine.
I went out today to work on it and first off started it and shut it off within a minute, no run on at all. So I then started it again and ran it until it was warmed up, I noticed the vacuum was at 15-16" the whole time, I then shut it down and no run on...go figure??? So I started it again and let it run a few more minutes, run fine, responded well no hesitation, no over fueling smell and it shut off just fine. So until I can take this truck for a drive I'll move on to other things, thanks Robert for your help really appreciated and will use this advice in the future if things start to act up again.
One thing I should mention, not that it had anything to do with it fixing it's self but I did add fuel stabilizer and sea foam in the tank.

[cdnwillyg]

I was going to paint the box on my truck until I talked with my painter who said it would take about $350 in paint supplies if I wanted to do it or $900 if he supplied the labor all in...no brainier here!! And he has a paint booth and can PAINT!!

[Bullitt74]

I was going to paint the box on my truck until I talked with my painter who said it would take about $350 in paint supplies if I wanted to do it or $900 if he supplied the labor all in...no brainier here!! And he has a paint booth and can PAINT!!

Good move! Money well spent there.

[cdnwillyg]

I think it is too Steve, takes alot of work off my list as well.
Today I sat in the Mercury and started it, drove it out of the garage, stopped all on its own since the day I brought it home, felt good.

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[Bullitt74]

I betcha that feels good to have done that - you're probably just itching to take it for a rip down your street...hopefully another week or 2 and the residential streets will be dry!