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Is THIS my problem?

Is THIS my problem?

Vvajk

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Location
Idaho
Vehicle(s)
1984 CJ-7, 4.2L inline six, T-5 Tranny, Dana 300 2 stick T-case, AMC 20 rear axle, limited slip diffs.
So lately, the CJ has been getting harder and harder to start. Granted, it sits for days at a time between runs, but to me still seems like it should be starting. Then, after a while, I start smelling gas, so I had my 11 year old son film the carburetor during start, and this is what he captured. I'm guessing this is the cause of my difficult starts. You guys? Video has been slowed down to 50%. Notice the diaphragm on the left side.

Motorcraft 2100 fuel leak. - YouTube

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Can you tighten the screws any?
CK all the carb screws and manifold bolts for tightness.
LG
 
Can you tighten the screws any?
CK all the carb screws and manifold bolts for tightness.
LG

I found a carb guy on youtube that says over tightening is actually one of the causes. I'm guessing I need to buy a new seal. I'm also wondering why a little RTV wouldn't solve the problem?
 
buy a gasket/rebuilt kit their only $25
 
Yeah I agree with Posi,

Gasket maker / RTV is great, don't get me wrong, but not for Carb unless emergency trail fix.

:chug:
 
?X on the carb kit! RTV+gasoline=problems. It doesn't usually last for very long.

"I like trail fixes, especially on somebody elses rig.":D
 
I agree with the rebuild kit idea.
 
Rebuild kit for sure and if its been a while a new fuel filter.
 
First-see if the screws are loose.;)
LG
 
Yeah, I will be probably buying a rebuild kit, which will be new and scary territory for me. But, this is how you learn right?

Do you guys think this is why the Jeep has been a pain to start lately?
 
. Notice the diaphragm on the left side.

Motorcraft 2100 fuel leak. - YouTube

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Maybe I am not seeing what the other problem is,but I DO see fuel squirting from the accelerator pump diaphragm vent hole.This is do to a faulty pump diaphragm. New diaphragm supplied in Kit along with other parts that wearout. Accelerator pump probably not funtioning very well.
The only trail fix would be to block off fuel between carb and diaphragm with a appropriate material then reinstall cover .:) mike
 
Like Mike said, the issue is the diaphragm, don't waste your time tightening screws it won't help.

Most likely has a pin hole, buy the kit and rebuild, its easy, trust me, it's easier then it looks.

accelerator pump diaphragm

DSCN0333.webp

Take pics before breakdown, separate all parts, take more pics, clean and reassemble. Your done. Set adjustment screws 2 turns out and adjust from there, chances you'll be at or around 1 1/2 turns out. Use a vacuum gauges to aide in tuning.

DSCN0326.webp

DSCN0336.webp

DSCN2978.webp
 
Check the flatness of the accelerator pump cover after you get it torn down.
 
Posi you got that bad boy looking good :cool:

OP pay attention to the kit you get - getting the right one is (for me) the hardest part. See the deep cap in Posi's picture below (I circled it)

attachment.php


On my carb (matching type) the kit I got was for this style cap over the power valve, the power valve itself was different (protruded more) - Since my cap was not deep enough to use the new valve, I had to re install my old one during a fresh nice rebuild..... that sucks...

I've yet to find the best way to check the power valve size, or where to buy the larger cap from (been lazy) but point is these carbs may all be the same, but small differences are there.

Rebuilding the carb was actually pretty fun though. Got a good step by step dismantle and re assemble instruction book from a ranger forum somewhere... I'll see if I can find the link.

:chug:
 
Maybe I am not seeing what the other problem is,but I DO see fuel squirting from the accelerator pump diaphragm vent hole.This is do to a faulty pump diaphragm. New diaphragm supplied in Kit along with other parts that wearout. Accelerator pump probably not funtioning very well.
The only trail fix would be to block off fuel between carb and diaphragm with a appropriate material then reinstall cover .:) mike

So that's actually a vent hole of some kind it's coming out of? It didn't start squirting out till I opened the choke . . .
 
Thanks JR, useful info

Side note: I just noticed I inadvertently posted a pic of the modulator diaphragm instead of the pump diaphragm sorry for the confusion.

So that's actually a vent hole of some kind it's coming out of? It didn't start squirting out till I opened the choke . . .

Vvajk, there is a vent hole on the pump cover just below the pump lever. However, after looking at the video again the leak looks to be coming from the side not the vent. The pump diaphragm is toast and needs to be replaced with a rebuild kit.
 
Thanks JR, useful info

Side note: I just noticed I inadvertently posted a pic of the modulator diaphragm instead of the pump diaphragm sorry for the confusion.



Vvajk, there is a vent hole on the pump cover just below the pump lever. However, after looking at the video again the leak looks to be coming from the side not the vent. The pump diaphragm is toast and needs to be replaced with a rebuild kit.

Gotcha! Thanks everyone for your input. I'm kind of scared to do it, but it's nice to know I can always count on some help from the best forum ever! :)
 

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