drifting timing (caution VERY long winded!)

drifting timing (caution VERY long winded!)
I have a climatic choke. It's not brand new, but I don't think it's 6 months old either. The choke is stuck closed, open, on, off I always get it backwards :)

The vacuum line to the power brake booster is the ONLY vacuum line that I haven't replaced....... hmmm.......



TDHofstetter said:
Those Motorcraft 2100-series carburetors really ARE very good carbs for these engines. We'll track down this bug & kill it & you'll be just WICKED pleased for having done the swap. :)
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WICKED pleased, now I know you're a New Enlgander :chug:
 
There is a check valve in the vacuum line from the intake manifold to the brake booster, just found that. Looks like I'm going to be replacing that.
 
elwood blues said:
There is a check valve in the vacuum line from the intake manifold to the brake booster, just found that. Looks like I'm going to be replacing that.
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elwood blues said:
~~~The vacuum line to the power brake booster is the ONLY vacuum line that I haven't replaced....... hmmm.......~~~
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Just cap it off with all the other vacuum lines and drive it. You should be able to handle the brakes for a while.
 
Old Dog said:
are you sure you don't need one? I would think you still would, the excess gas has to go someplace.
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It'll just pressurize behind the regulator - no problem.

That does bring up something we oughtta' look at, though - a MotorCraft carburetor wants 4 to 7 pounds of fuel pressure, which is just about what either a mechanical or electric fuel pump puts out. There shouldn't be any need for a regulator behind it unless a high-pressure fuel pump got used. We might want to look into that fuel pressure - before and after the regulator - too.
 
O.k. so you got your carb in good running order I presume. What I'd like to know is how long approximately does it take for the vacuum advance to kick in? Could it be that it kicked in at the point it stalled out and died? I thought you went with an h.e.i. dizzy? If so Id take a look at putting your old one back in just to see if it corrects the problem. At least you'd know and wouldn't throw more $$ at it for nothing. Finish what your doing to correct it now and if that doesnt help maybe you wanna try that? :dunno:
elwood blues said:
As a matter of fact she sat right there and idled pretty well for a good 15 minutes.

I think it's just cold, no big deal. Well, after I'm sure it's good and warm every time I left off the gas it tries to die.

The only two things I haven't replaced are the distributor, or the summit ignition box
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Old Dog said:
are you sure you don't need one? I would think you still would, the excess gas has to go someplace.
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with the mc2100 no bypass filter needed mine doesn't have one and i'm using the mr gasket fuel pressure reg. no problems. its regulated down to 3.5 psi and runs fine, a little rich but my carb needs a professional rebuild which it will get soon
 
Petescj said:
O.k. so you got your carb in good running order I presume. What I'd like to know is how long approximately does it take for the vacuum advance to kick in? Could it be that it kicked in at the point it stalled out and died? I thought you went with an h.e.i. dizzy? If so Id take a look at putting your old one back in just to see if it corrects the problem. At least you'd know and wouldn't throw more $$ at it for nothing. Finish what your doing to correct it now and if that doesnt help maybe you wanna try that? :dunno:
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I don't know Pete, I'm not so sure the carb is in good working order just yet. I don't think it's the vacuum advance because one I had it capped off, and two all I did was "blip" the carb and on it's way back down in rpm's it just dies. As for the dizzy, I just went with a remanufactured oem replacement dizzy, not an h.e.i. Which, there's still the posibility that I got a bad remanufactured dizzy, I haven't ruled that out yet.


Cheepjeep85 said:
with the mc2100 no bypass filter needed mine doesn't have one and i'm using the mr gasket fuel pressure reg. no problems. its regulated down to 3.5 psi and runs fine, a little rich but my carb needs a professional rebuild which it will get soon
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Cheepjeep, what jets and power valve are you running? The only place I've found to buy jets is CARBS UNLIMITED, and they're not cheap either, they're $9.98 a pair. But I've never found a good source for Motorcraft/Autolite power valves, got any good leads?
 
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Ok. As far as the power valve for the Mc2100 I just got one at Napa. They had to order it but it only took like 2 days. It just strikes me funny that a fuel delivery problem would make that motor shake like that.Do you still have your old dizzy?
elwood blues said:
I don't know Pete, I'm not so sure the carb is in good working order just yet. I don't think it's the vacuum advance because one I had it capped off, and two all I did was "blip" the carb and on it's way back down in rpm's it just dies. As for the dizzy, I just went with a remanufactured oem replacement dizzy, not an h.e.i. Which, there's still the posibility that I got a bad remanufactured dizzy, I haven't ruled that out yet.
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Ponycarbs is a little ridiculous, they want $239.50 to do "standard" rebuild on a MC2100 carb and you have to pay to ship it to them. Plus they have a minimum $50 parts order. For those prices I can buy a brand new Holley carb completely set up for a AMC 258 i6 / 4.2l from Summit.

I've also spent the last couple hours scouring other websites for information on the MC2100. Here's what I've found so far

NAPA part numbers;
CRB 24410 is a standard MC2100 rebuild kit
CRB 25585 is a 2 stage power valve first stage 8.5hg second stage 4.5hg (I didn't write those numbers down, I should have, but I think those are correct)

Also, Holley carburetor powervalves fit in a Motorcraft carb and the Hg ratings are the same.

I'm off to NAPA to order some parts.
 
i'm running #46 jets the smallest i could get through carbs unlimited, and yes you can use holley power valves i'm running a hg 10.5 but i may try a higher rating power valve if i can find one. as far as carbs unlimited goes you can order just one pair of jets through them but they charge around $10 just for shipping and handling which is ridiculous because they just stick em in an envelope and drop them in the mail if i remeber right they come from up there around you somewhere. the hg 10.5 is what was recommended to me by the guys over at cjoffroad.com and it works pretty good but i'm still a little rich but i'm pretty sure the carb needs a good rebuild because i don't have vaccum on one of the ports that i know is supposed to have it
 
If you never read this, there's a lot of good info here Holley Performance Products Technical Library If you have read this than maybe it will help someone else.:)

A good vac guage and a wideband A/F guage will go a long way in setting up a carb.
 
Been awhile since I was around a carb some really great info.I'll bite A/f gauge what is it?
Hope your getting closer to a answer EB.
Mike:)
 
air to fuel ratio gauge it takes a reading from the o2 sensor and tells you how rich/lean the fuel mixture is. the local carb guy only charges $100 and he does a really good job. although i really want to learn to do this myself. i rebuilt this carb once but must have missed something i am going to learn to do it right. i'll do a write up on it but i'm going to talk to the carb guy before i do to make sure i do it right and i'll post my results
 
...for which purpose a multimeter works quite well. :)
 
For reading the O2 sensor. The multimeter. Instead of a dedicated A/F gauge.
 
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