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Hesitation during acceleration

I have a 89 Wrangler Laredo that I recently purchased. I've been going through all of the normal tuneup steps (new plugs, plug wires, cap, rotor, fuel filter, timing, vacuum tube, etc.) in order to get the Jeep ready to be a daily driver. Had the timing adjusted yesterday (was getting rough idle to the point of stalling and severe pinging during acceleration) and new issue came up. After about 20 minutes of driving the Jeep would hesitate and "stumble" during hard acceleration. I first noticed it going up a slight incline on the freeway, then fairly consistently on surface streets. The engine never stalled, but sounded like it needed more gas. I am thinking this is a carb tuning issue. I am new to Jeeps and trying to learn more, but any suggestions would be much appreciated.

Reply to
Ethan
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Reply to
L.W.(ßill) Hughes III

Might want to check out the accelerator pump on the carb to make sure it's working properly. With the engine off and the air cleaner removed, you can open and close the throttle while looking inside the air horns. Each time the throttle is opened a fairly good stream of gas should squirt out.

If the stream is weak when you quickly open the throttle, check the linkage rod that connects the throttle to the pump and make sure it isn't bent. You can verify that the pump is the problem by trying to slowly accelerate, if no stumble then it's likely the acceleration pump. There might be a section in the service manual that explains how to adjust or check the adjustment of the linkage rod and that's where I'd start.

I agree that changing the filter would be a good idea (didn't you already do that), but would check out the carb first before going to the expense of replacing the fuel pump.

Good luck! John

Reply to
John W.

You could be easily describing a dirty air filter on the gas tank vent. When plugged it puts a vacuum on the gas tank causing the symptoms you describe. If it gets really bad, it will even act like it runs out of gas.

The filter is about two bucks and is on the bottom of the charcoal canister 'way' down under the brake booster. To test, drive with the gas cap loose or unplug the very top hose on the carb float bowl to see what happens.

Also a rebuild kit for that carb is in the twenty dollar range and is a good thing to do now and then. The manual says with every plug change.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Ethan wrote:

Reply to
Mike Romain

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