Injector Pump Replacement Time:

[Doktor Bert]

Well, it would seem that the old IP in my 300SD is saying goodbye. I guess with roughly 1,309,000 miles on the pump itself, I cannot blame it.

At 1, 244,000 I rebuilt this engine/transmission complete. Liners, pistons, cam, followers, valves, guides, even the bushing for the IP drive were replaced. The idle was great on the old IP until about 1,275,000 when I picked up a shake at idle. My 617.950 IP was an early model without a rack damper, so I installed a rear plate and damper which smoothed things right out.

Recently, I started picking up this intermittent shake at idle that would come and go, and if I lay my foot on the throttle, it will go away. I had a new rack damper in the package, so I installed it earlier this week. I started the engine with the damper loose and it almost rocked itself out of the car!

A full turn of the damper after contact smoothed the engine right out, which is a bit much, since usually, on a good IP, 1 flat will do the job.

I asked in a previous post for some So Cal shops that are familiar with our pumps. To that end, I wanted to ask what you gentlemen are actually paying to have a pump refurbished.

I am looking at three options at present:

1. Lower mileage used IP

2. Replacing all the wear parts myself and then paying for the calibration

3. Having the rebuild and recalibration done by a shop

Naturally, cost will dictate, to a large degree, my course of action, but your input is valued.

Thanks, Robert