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Discussion Starter · #1 ·
This is a wierd question. My quickly dies after I take a short trip and stop the engine for 5 minutes and then restart. In hindsite, I think I had vapor lock because I didn't use the 3-prong fuel filter (and blocked the return-to-tank line) after my Weber upgrade. But at the time I thought doing the HEI Upgrade was the solution. So here's what happened...

I dropped in an HEI distributor (coil built the cap). I totally bypassed the old ICM, splicing the heavy yellow as the new hot-wire for the HEI. I took the yellow&green and sent that to the tach output from the new cap/coil. My Jeep continued the stall problem, so I thought the computer behind the dash was bad. So I decided to try the Nutter bypass.

I was impossible to work under the dash, but I eventually was able to unplug the big/long wire harness that goes into the computer. Just for grins, I tried to start it... and it started just fine! My tach was working and nothing seemed different. So I didn't touch a thing and left it all.

My question is... Did I inadvertantly bypass the computer when I did my HEI? (do the Nutter bypass?)

On a related topic, now that I had the HEI.. I re-adusted my timing to about 9 BTDC (w/ vacuume advance disconnected). If I set it at like 14 or so, the RPMs are noticibly higher at idle (still no vacuume advance). Is that normal?

Thanks for reading all this..

(ignore any Jacobs stuff in my auto-suffix)

'88 YJ 4.2L, 32/36 Weber, Jacobs Ign, 2.5" spring lift, 31" BFG ATs.

· Registered
1,736 Posts
Sammy, yikes! /wwwthreads_images/icons/smile.gif

OK, first off, I've run without the fuel return line on my 88YJ, 258, stock mechanical fuel pump, weber carb for years now with no fuel vaporization problem, summer, winter, etc. Granted, not in places like Death valley, but, still.

If you've put in the HEI ignition, and powered if from a simple 12v+ wire, you've totally eliminated the stock computer, ignition, etc., so anything to do with the Nutter Bypass, and any of that stuff, does not apply.

I'm not sure on what my timing is set at - I just run it up until it pings and back it off a bit.

With the weber and your HEI, you can create a VERY nice running jeep. Mine runs great. /wwwthreads_images/icons/smile.gif

If you have any other weber/HEI combo questions, I would be glad to answer what I can for you.

email me at [email protected]

Good luck

88 YJ - trails/beach trips only!/wwwthreads_images/icons/smile.gif
79 4WD F250-hauler/tower of my toys
70 Jaguar E-type - the best car England ever made. /wwwthreads_images/icons/cool.gif
90 Honda CRX - Daily pavement-pounder. 42 MPG. /wwwthreads_images/icons/cool.gif

Discussion Starter · #3 ·
Thanks for the tip. I agree w/ everything you said, except I'm PRETTY sure I had vapor lock. I haven't stall since I put the fuel-return fuel filter back in, and appearantly the computer was completely out of the loop when I did the HEI.
I had one of those clear-glass fuel filters in before, and I could watch the fuel level inside it sometimes drop to about 1/4-filled. (and then recover)

Anyway, thanks again for your help!


'88 YJ 4.2L, 32/36 Weber, Jacobs Ign, 2.5" spring lift, 31" BFG ATs.
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