post #1 of Old 03-21-2012, 06:47 AM Thread Starter
superj
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motorcraft power enrichment valve

how easy is to blow these suckers? i put a 2100 on and changed the power valve and accelerator pump because it was having issues which google told me would be these two parts. after putting new parts in, drove perfectly. then yesterday morning, got a little pop back through the carb and now i am having original trouble again.


this is actually the second motorcraft i have tried out and i cannot get these things to either run right or last running right. i don;t know why the jeep back fired through the carb, it has not done it before or after but it did. i am tired of screwing with the dang fuel metering system on this jeep and its making me not like having the jeep anymore. i grew up with carbs and had them on hondas, mustangs, vws, and bmws with no trouble but i just cannot get this jeep to run perfectly on one. and when i do, its either short lived or the gas mileage is so incredibly bad that i cannot stand it.


its a 2100, not a 2150. i have slightly larger venturis since the engine is slightly larger then stock. i have 1.14 with 48 jets, which should be acceptable. it ran on a 1.21 but was idling badly from the venturis being a bit to large. the idle would hunt with that big carb.

so, whats ya'lls thoughts on the power valve? is anyone else running a larger size then a 1.08? the 1.21 i got from a guy who was running it on his yj and he said he had no trouble.


I don't feel like working on anything, at this time.
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post #2 of Old 03-21-2012, 06:59 AM
Beachcruiser
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I have a 2100 & it runs perfectly. Good power, too.

Backfire thru the carb (what blows the power valve) is usually caused by being too lean, or timing way off.

First make sure your timing is correct.

At sea level, I'd bet those 48s are too lean in a 1.14. I've seen those jets in a 1.08 (mine runs 47s & is pretty lean).

How do your plugs read? If they are much lighter than a deep tan, you can afford to go richer.

I'd also check float level.

I set up my carb to the factory specs & it runs fantastic!

A quick Google turned this up: "The 1.14 2100 was used on 289 engines in at least '65 and '66. The jet sizes range from 49 to 51"

At your altitude, I'd run 50's, w/ correct timing, for a starting point.

probably out breaking stuff.
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post #3 of Old 03-21-2012, 07:21 AM Thread Starter
superj
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hmm, ok. i will have to find some online then. i have 42s, 48s, and 52s

my engine is roughly 275ci so the 1.14 should be pretty close to perfect and i pulled it from a 302 with the jets in it and it ran great with this set up.

timing is 9 or 10 degrees, i can't remember which.

it just aggravates me to continually have to adjust a carb or mess with it. once i got the carbs on the other vehicles set right, i never messed with them again but on this jeep, every carb has needed continuous adjustments, even the great running holley that was on it recently (only removed because the idle mixture screw broke off)

I don't feel like working on anything, at this time.
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post #4 of Old 03-21-2012, 07:22 AM Thread Starter
superj
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i wish i could find a 1.08 locally but all i have found are 1.01, 1.14, 1.21, and another one a little larger. no 1.08s in the junk yard here

I don't feel like working on anything, at this time.
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post #5 of Old 03-21-2012, 07:42 AM
Beachcruiser
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Go w/ the 52s then. I found my 1.08 off local Craigslist.....but the 1.14 should be fine on your rig.

Once you get it dialed, it should be a rock-steady carb.

Make sure you've got a steady acc pump shot coming out of both jets when you open the throttle...they can get plugged. I'd start w/ the rod in the 3rd hole on the throttle shaft arm and inner hole on the pump arm. You can get a carb backfire w/ too little pump input, too.

probably out breaking stuff.
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post #6 of Old 03-21-2012, 12:21 PM Thread Starter
superj
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I'll swap them tomorrow morning then, I just parked at work. I get a good solid twin stream at the accelerator pump squirters. When the carb first was put on, I got a puny thin stream and hesitation so I sprayed them a few times bit ended up having to run a thin piece of metal down the things to get them cleared properly. Even though I took the whole Carb apart and sprayed it all out, I think I should have put it in the dip for a night or two. Seems like little pieces of something are getting into it a lot more then any other carb I have ever had.

I'll tell ya how it goes once I swap jets

I don't feel like working on anything, at this time.
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post #7 of Old 03-21-2012, 03:13 PM Thread Starter
superj
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what is the float supposed ot be set at? i know this one is not right

I don't feel like working on anything, at this time.
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post #8 of Old 03-23-2012, 11:03 PM
Beachcruiser
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Have you got any numbers off the baseplate?

From what I've seen, it's in the ballpark of 1/4-3/8 down from the top edge of carb body w/ the needle just seated. I think mine was 5/16 or so. If you have a year, or carb # you can search the mustang forums or Pony Carbs & find your spec. Because they are so basic, float level makes a big deal.

http://mustangtek.com/2100/ford2100.html will get you started if you have a #. Once you know the model/application...you can google the specs.

probably out breaking stuff.
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post #9 of Old 03-24-2012, 06:58 AM Thread Starter
superj
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It's off a 65 mustang 289. I have the tag on the carb still so I ran the numbers. I hadn't gotten to switch the jets yet so today is the day to do everything

I don't feel like working on anything, at this time.
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post #10 of Old 03-24-2012, 07:24 AM
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I'm not familiar with the 2100, but could a Holley power valve check ball kit be installed in it so you don't pop the valve? I did one on a double pumper and never had to change the valve again.
http://www.summitracing.com/search/D...s/?Ns=Rank|Asc

MCLMM
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post #11 of Old 03-24-2012, 08:38 AM
Beachcruiser
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Float level for a C5ZF-B should be (according to vintage mustang forums): "for your carburetor it should be 15/32 +/- 1/64 measured 1/8 from the float end." A C5ZF-A will be very similar.

Most rebuild write-ups say 7/16" at end of float to top edge of carb body. That's what I set mine at. They also say the MC carbs like 4-5 PSI of fuel pressure, but I didn't bother to put a guage on mine.

probably out breaking stuff.
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post #12 of Old 03-24-2012, 08:54 AM
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I tried a 1.21 on my 4.7 stroker I had a off idle bog I could not tune out. I dropped a 1.08 in there and it runs near perfect. I have not changed a power valve or pump in 4 years.
A backfire will kill a power valve you probably need to look into that.

Dwayne
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post #13 of Old 03-24-2012, 10:25 AM Thread Starter
superj
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Yes sir. It's being changed today.


What's a power valve check ball? Google, here I come

I don't feel like working on anything, at this time.
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post #14 of Old 03-24-2012, 12:08 PM
Beachcruiser
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Quote:
Originally Posted by 4.7stroker View Post
I tried a 1.21 on my 4.7 stroker I had a off idle bog I could not tune out. Dwayne
Wow, I'd have thought a 4.7 stroker w/ the 4.0 head would flow enough air to be fine w/ a 1.21 version.

I pulled plugs today to do the poor man's check for air/fuel ratio.....& they still look pretty light for 2 weeks worth of driving. Mileage is much improved, but I could probably gain some HP by moving up to 48/49 jets.

probably out breaking stuff.
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post #15 of Old 03-24-2012, 10:19 PM Thread Starter
superj
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I got my intake off and carb off. I didn't realize how different the offy was in the mounting bolt area so I had to spend today making the intake bolt on versus actually swapping carbs and power valves & jets. Hopefully tomorrow I can tell y'all about how much better it runs.


That check valve deal goes on the lower plate area but the 2100 isn't listed on the carbs to use it on. Not saying it can't but I will have to find one of those kits and try out a spare 2100 before I do this one

I don't feel like working on anything, at this time.
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