hesitation

[oreo3156]

I have an m38a1 with the F134. Here's what I have done:

electric fuel pump geared up regulated to 7 psi.
converted over to 12 volts Delco Distrubtor, 12 volt coil, etc.
Timing is spot on.
Rebuild the carb and installed it.

Jeep fires right up and idles great. Give it a quick shot of fuel and it dies. Press the fuel pedal very very slowly and it will rev right up.

I do not have the pcv valve hooked up. ( I don't even know what it does) all I have is the intake hose hooked up from the carb to the air box. I do not have any other vent hoses hooked up.

The intake gasket is not leaking, already checked that. There is a metal tube for vaccum (I think) that goes in the middle of the intake breather hose, but nothing is hooked up to it.

Did these jeeps have vaccum advance? Does the carb have an accelerator pump I might have missed?

Any ideas?

[wesk]

The distributor does not have vacuum advance. You set timing to 5 deg's BTDC and then the centrifugal advance (governor) gives you a total of 11 more degrees at the higher RPM area.

The carb has vacuum operated accelerator and main metering jet. If you used an OLD NOS rebuild kit you will have bad rubber diaphram parts. Another common screw up is to get the springs on the wrong side of the diaphrams or to get the springs mixed up. Who rebuilt the carb?

The vacuum system, dual vac/fuel pump and the fording air control system are quite complicated and should be completely assembled correctly or you should consult with a very experienced mechanic on how to do work arounds for substituted parts and omitted parts.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[oreo3156]

thanks for the input. To answer a couple questions, I'm not using the fording kit and I bought a kit to rebuild the carb at a local shp. Think it was made by Holley actually.

Here is a pic of my carb after the rebuild. The line circled in green is for the fuel line. The line circled in red has been plugged off. (I believe it is suppose to go to the breather hose.) Think that may be the problem?



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[usma41]

Looks like a Carter to me.

[oreo3156]

yes, the carb is a Carter YS, it was kit that was made by holley

[usma41]

Has it a small or large opened manifold throat? Sometime if you put the wrong gasket on it, it will dump fuel right into the manifold. That is if you put the gasket on it for a large and the throat is small, thats what will happen.

[wesk]

That fitting on top is the bowl vent. If you plug it you will have the synptoms you describe.

I wasn't aware of any commercial US carb kit suppliers that manufactured a kit specifically for the M38 YS637S or the M38A1 YS950S carbs.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[oreo3156]

I think the box the kit came in got thrown out, I'll check, if it didnt, I'll get the part #.

thanks for the help. I'll try again tonight and post my results.