You need a special bench to calibrate an IP such that the right amount of fuel flows to each cylinder based on the rack position. So you'd need a mini chem lab (tubes, graduated cylinders, timers, etc.) and the specs for the IP, not to mention replacement parts and seals. The shop that rebuilt my IP had a computerized Bosch bench that had a graphic display of IP output for each injector and calibration go/no go bands for the rpm, throttle position and ALDA pressure input. I don't remember if the control rod sensor and idle control device on the back of the IP were connected.

A rebuild is about $750. A little more to clean and balance injectors (might as well). Check with Phil for rebuilt IPs. www.adsitco.com offers used and rebuilt IPs.

Why do you think there's a relationship between double pumping and the ALDA?

Sixto
95 S420
87 300SDL