Accelerator Pump Lever - Which Hole?

[Mike Armstrong]

I have a 2150A carb on my stock (no smog) 2.8. My Ranger/Bronco II manual says the Accelerator Pump Lever Location is supposed to be located on #4. I'm assuming that means the 4th hole, however there are only 3 open holes to choose from and currently it's on the 2nd hole.?

Reason I'm looking into it is I have trouble with cold starts and have hesitation when I hit the gas. The pump (replaced leaking diaphragm) is squirting in fuel but it doesn't look like much. Timing and mixture has been adjusted.

 

[260Alpine]

Mike, is the hesitation only when cold or all the time? I would put the accelerator rod in the top hole and tweak the rod to just touch the plunger so it pumps immediately. Are both tubes squirting gas? Throttle shaft wear or gasket leak can cause a vacuum leak also. Your choke may need adjustment and you may have too cool of a thermostat for a longer warmup? How's that shifter working?

 

[Mike Armstrong]

Mike, is the hesitation only when cold or all the time? I would put the accelerator rod in the top hole and tweak the rod to just touch the plunger so it pumps immediately. Are both tubes squirting gas? Throttle shaft wear or gasket leak can cause a vacuum leak also. Your choke may need adjustment and you may have too cool of a thermostat for a longer warmup? How's that shifter working?

Hi Jim.

Yup, difficult to start, seems I have to pump the gas a few times and hold the pedal down for a few seconds, releasing it then try starting. There is gas squirting out of both tubes, not allot though, like I've seen in some videos. No play in the rod so it does push on the plunger immediately.

According to the Temp gauge, the engine warms up pretty quickly but 20 minutes later the choke plate will still be only about half way open, it does 'eventually' open all the way. I tried turning the choke cap clockwise to cut down the amount of time the choke plate opens but if I turn it too much it is then forced open farther than what it's supposed to be for the choke pull down spec.

The new shifter went in easily and I think is going to be a great improvement. I'll have time to road test it today.

 

[260Alpine]

Mike, If the rod is too tight on the plunger and already pushing it down you will have less stoke also. Some 2150's had 2 holes in the arm also with the outer hole a quicker shot of gas. You can bend the rod where the existing bends are to adjust. Should be slack with no gap.Maybe the choke isn't closed all the way for cold starts. If it has a hot air tube it should go directly to the header to warm up faster. Sinking float will let the fuel level drop also. Try turning the key on and let the electric fuel pump run for 30 seconds before starting. Then turn over without touching the gas.

 

[Mike Armstrong]

Thanks Jim.

I moved the lever to the top hole for the greatest amount of stroke. To do this I had to remove the metal pin holding the plunger arm to the metal plunger fixture. This's allowed the lever to be rotated enough to disengage from its current hole.

That did the trick! I used to see an 'ok' amount of fuel kind of squirt out of the tubes, now a good amount actually does squirt out. I only had to pump the gas once to get it cold started. Once warm there is no hesitation when I hit the gas and while driving there is much better pickup when I stomp on the pedal

And yes, with the new shifter, shifting is much better!

 

[260Alpine]

Mike, Great News! Your experience will help others diagnose issues.

 

[Mike Armstrong]

Thanks for your help Jim.

In one of those articles it mentioned that the lever was set at the factory to save fuel and/or EPA reasons, not for performance, and it was never ment to be changed.

It makes sense for our usage, smog devices removed, performance oriented, that the lever should be moved the next notch up to allow the accelerator pump full stroke.