Engine/Transmission (1994 - 1998) Hand pump for regulated air to test AFC, wastegate?

[CTD12V]

I have seen it mentioned in various threads on this forum about using a hand pump to supply regulated air to test calibration of the AFC, and I also need it to check my wastegate. Where would I find such a pump, and is there any particular style that works better or is easier than others? I assume it should come with an integral pressure guage? I also want to check my mechanical fuel pressure guage to see if it is still accurate since it receives a fair amount of minor pulsation even with a snubber AND a needle valve cranked down.



Not sure if this is the best forum to post this, but I figured people with an AFC would be more likely to know/have a pump like this . . .



Thanks,



CTD12V

 

[pwerwagn]

I always just use my shop air compressor and a regulator to do AFC work. I dont see why you couldnt use a bicycle pump though, as long as you have absolutley no AFC leaks!

 

[CTD12V]

Are the regulators that connect inline on the air hose fairly accurate? The ones on my compressor are really lousy.

 

[JMalik]

I went down to my local bycycle shop and got a strut pump with a gage on it. I changed the gage out for a more accurate gage and got a hose fitting which would screw into the AFC housing. The rig works OK. With it you can set your AFC spring preload pressure where the AFC starts fueling. I ran pressure vs AFC control arm displacement curves and found that the spring preload just moves the AFC fueling start point up and down the pressure axis where the spring constant then determins the rate of onset of fueling when the spring preload pressure is exceeded.

 

[CTD12V]

I went down to my local bycycle shop and got a strut pump with a gage on it. I changed the gage out for a more accurate gage and got a hose fitting which would screw into the AFC housing.

Were you perched on the bumper operating the pump or did you get a lot longer hose? I have several bicycle tire pumps, including a frame mount one -- I wonder what the best way to rig a guage inline would be?

 

[CTD12V]

I ran pressure vs AFC control arm displacement curves and found that the spring preload just moves the AFC fueling start point up and down the pressure axis where the spring constant then determins the rate of onset of fueling when the spring preload pressure is exceeded.

Cool. That makes sense. Did you figure out what the difference is between how the spring rate affects fueling and how sliding the AFC housing affects fueling? I haven't quite stretched my mind around that part yet.