Fuel Accelerator Pump Lever - Which Hole?

[TenSeven]

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 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.

 

[RonD]

Center hole is where you start, move it out to the farthest hole now, that will cause more movement in the pump and more gas to be squirted in.

This could help cold start, if you are pumping gas pedal once to set choke, but it doesn't effect overall mix after initial squirt of fuel.

Accelerator pump was added because of the delay(hesitation) between air flow increase of throttle plate being opened and main jets response in adding fuel, jets work on airflow and vacuum sucking out fuel from the jet openings, vacuum drops initially as throttle plate opens so fuel from jets drop.
So a hesitation would be a sign of accelerator pump not working at all or adding too little or too much fuel.

TPS(throttle position sensor) serves similar purpose on a fuel injected engine, because there is a delay(hesitation) between MAF sensor air flow data and the throttle plate opening, TPS gives computer a "heads up" to add more fuel instantly as throttle plate opens.

 

[TenSeven]

Center hole is where you start, move it out to the farthest hole now, that will cause more movement in the pump and more gas to be squirted in.

This could help cold start, if you are pumping gas pedal once to set choke

Thanks Ron.

Yup, pumping the pedal once to set the high idle cam. But I noticed I've had to pump it several times, there's fuel in the carb but maybe not enough.

 

[TenSeven]

Before I break it , do the Lever ends just pop off?

 

[RonD]

No, one end will have a clip on it, probably throttle shaft end on 2150, that needs to be removed and then rod can be pulled out and put in another hole at that end or if there are other holes on the pump lever arm you can swing the rod around and it will lift out of the arm.
Rod has a tab that sticks out on one end that keeps it from popping out of the hole, so it has to be rotated so tab can slide thru the hole only at one angle.

Look here for 2150 tips: http://www.autozone.com/repairguides/AMC-Coupes-Sedans-Wagons-1975-1988-Repair-Information/Fuel-System/Autolite-Motorcraft-2100-and-2150-Carburetors/_/P-0900c1528008557e

More info here but scroll down a bit for 2150 and 2150A adjustments: http://www.autozone.com/repairinfo/repairguide/repairGuideContent.jsp?pageId=0900c1528004e0d6

 

[TenSeven]

Thanks Ron.

 

[TenSeven]

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.

Thanks again.

 

[RonD]

Good work

 

[AndyB.]

 

[TenSeven]

Thanks Andy.

 

[Mark_88]

Looks like they are not meant to be moved by the information in the link Andy provided...

Was this a new carb on an old motor or did you inherit it from someone like that?

 

[TenSeven]

Looks like they are not meant to be moved by the information in the link Andy provided...

Was this a new carb on an old motor or did you inherit it from someone like that?

Hi Mark.

I agree, they are set at the factory specifically for the engine the carb is to be used on and not meant to be moved after that.

This carb was on the engine when I bought it and from what I gather it would be correct for the engine and vehicle that is reportedly came from, 1985 Ranger 2.8. Being the 'A' computer controlled model it had all the electronic smog devices on it.

Big difference in moving it up to the top notch though, good starts, great acceleration.

 

[Mark_88]

Could be a number of things that got it to where you needed to adjust...but primary suspect would be previous owner tinkering with it trying to either get more out of it or correct something wrong...

It happens...and then someone else gets to guess what happened.

I bought a 2.0 from a friend who had someone else do his work on it...and I can attest to the mess...unfortunately the guy who did the work was not available so I couldn't pick his brain...and spent about a year trying to figure everything out...ended up swapping out the whole carb and intake and that finally fixed all the problems...except the float level....but thanks to someone on here I figured that out eventually.

I would try to grab a copy of that book that Andy has...looks like an excellent resource...

 

[AndyB.]

In the image I posted from the service manual, which number hole corresponds to the top notch?

All of that electronic smog stuff is what makes these carbs operate correctly.

 

[TenSeven]

In the image I posted from the service manual, which number hole corresponds to the top notch?

All of that electronic smog stuff is what makes these carbs operate correctly.

In your diagram, the top notch, or hole, is indicated by the number 4 (which is also the #4 notch specified in my Chiltons). The diagram shows it connected to the number 3 notch, just as mine used to be.

I agree, normally, the 2150A and the smog stuff work hand in hand. However, 'with modification' (Smog removed, Duraspark II, a manual metering block and plug all the leftover holes) my 2150A seems to be working fine without it. I still connected the PCV valve though. The only other thing I had to do was use manifold vacuum for the dizzy vacuum advance because the 2150A doesn't have a spark port (well, at least mine didn't).

Thank for that diagram, it confirmed what my manual was saying.