Mechanical Fuel Injection Pump

[Ken Cox]

Hello to all From Cornwall Ontario Canada.

 I have a 69 280 SL and need to have my Injector pump Repaired. Thought of doing it myself but looks like to many special tools are required.

Any one know of some place to send it to. I live 20 Min from Massena NY

TTFN Ken Cox

[George Des]

Ken--many, mnay posts on this. Do a search on FI Pumps. Hans is close by to you in Batavia NY--he's one of the experts on these. Others have used Farichild on the West Coast. Expect to pay around $950 or more for a coplete overhaul. It's well worth it in terms of engine performance and peace of mind. Good luck.

George Des

[Ricardo]

Hi Ken
Welcome and glad to see another pagoda in the area...I'm in west Quebec about an hour from Ottawa, so we're nearly neighbors  
For more on locations of other members check out the Frapper connection on this site's home page....
For injection pumps you can also send to our buddy and one of the site's guru's, Dan Caron a.k.a. the Benz Doctor or Dr. Dan...he has  an injection shop that he uses and they did my pump a couple of years ago after it self destructed heading down the highway...Dan had a parts pump or two and the shop was able to rebuild it at a reasonable price.....but make sure you need this done as they are very reliable pumps and often the running issues are NOT the pump....check out everything else first...the going rate for pump rebuilds is in the neighborhood of $1500 US and apparently they often don't need rebuilding.....tell us what you are experiencing and we can steer you to the likely cause....
Too bad it's the end of top downing for us this year...we are always looking for destinations and Cornwall is lovely

[Douglas]

(By the way, Hans is in Bohemia, NY on Long Island. His shop is H&R Fuel Injection on Knickbocker Road. I recommend him highly.)

Douglas Kim
New York
USA

[Ken Cox]

Hello Ricardo. I have been to Shawville several times. We have a coyyage at Mink lake just south of Renfrew.

My engine is running on 4 to 5 cylinders. THE CAR SAT FOR FIVE YEARS. i PULLED THE SIDE PLATE OFF THE PUMP AND WHILE CRANKING FOUND THAT TWO OF THE PLUNGERS WHERE NOT MOVEING. aLSO I DO GET GAS IN THE OIL. I do need some addresses and numbers to start calling around. I am a licensed mechanic and do know a lot about this car. I bought it in Lahr Germany in 1981 sold it to a close friend in 1987 and bought it back in June this year. It is in real fine condition except for the pump and brakes.

Call me if you wish

Ken Cox 613 938[:p] 3375

quote:Originally posted by Ricardo

Hi Ken
Welcome and glad to see another pagoda in the area...I'm in west Quebec about an hour from Ottawa, so we're nearly neighbors  
For more on locations of other members check out the Frapper connection on this site's home page....
For injection pumps you can also send to our buddy and one of the site's guru's, Dan Caron a.k.a. the Benz Doctor or Dr. Dan...he has  an injection shop that he uses and they did my pump a couple of years ago after it self destructed heading down the highway...Dan had a parts pump or two and the shop was able to rebuild it at a reasonable price.....but make sure you need this done as they are very reliable pumps and often the running issues are NOT the pump....check out everything else first...the going rate for pump rebuilds is in the neighborhood of $1500 US and apparently they often don't need rebuilding.....tell us what you are experiencing and we can steer you to the likely cause....
Too bad it's the end of top downing for us this year...we are always looking for destinations and Cornwall is lovely

[ja17]

Hello Ken and welcome,

A slight amount of moisture can cause the plungers in the pump to rust and to stick.  When this happens the rack in the pump also binds and the mixture stays too rich and oil can become saturated with fuel. Any stuck plungers in the pump result in those cylinders getting no fuel at all and the others getting too much.

You can often resolve the problem without a major pump rebuild or without removing the pump from the engine. Remove the injector lines at the injection pump, remove the 19mm fittings on the pump over the stuck plungers. The ball check valves below the fittings are threaded on the outside so you can remove them from the pump. Find a metric fitting to thread over them for removal. After the ball check valves are removed you can look down on top the injection pump plungers and cylinders. Use lots of penetrating oil, and turn the engine. Occassionally tap down on the top of the stuck plungers. If your lucky they will begin to move eventually returning down on their own. It may take some time. Repeat the process as needed. Keep tapping them down as you  use the penetrating oil.

The rack in the pump has a opening at the front of the pump. If you remove the small rack cover you will find that the rack is stuck. It will be difficult to move until all the plungers are free. Exercise the rack and the accelerator linkage going to the pump during the process of freeing up the plungers. Eventually everything should begin to  free up. After the rack and plungers are free, check the warm up device on the top of the injection pump. A slide valve gets stuck in this device.

During re-assembly make sure to torque the 19mm fittings to 18 ft. lbs. This is critical. You may also wish to add a little two cylce motor oil to your fuel for the next tank or two, to keep things lubed inside the injection pump.



Refer to "injection pump tour" on this site for some insight on the injection pump before you begin. Keep us up to date.

Joe Alexander
Blacklick, Ohio