Injection pump no fuel out of #3 of pump rebuild??

[BaronYoungman]

Tested my injection pump and gas out of each # except #3 NOTHING! Is it possible just one is stuck and others OK or does this mean full rebuild of the pump?
Thanks, Bob
I checked archives but no one seems to have checked each seperately and found one that pushed out NOTHING.  One article said to see Joes stuck thread but did not say Joe who and couldn't find it.
Thanks, Bob

[mdsalemi]

Bob,

With all due respect to the millions of "Josephs" and "Joes" in the world, when anyone here refers to something "Joe" said, with nearly 99.99% certainty it is Joe Alexander, JA17, PUB host.

Maybe now you can ferret it out, or JA17 himself will read this, or you can contact him.

Also, you are not that far from Black Forest and maybe a call to Michael up there might be useful...

[ja17]

Hello Bob,

If your injection pump is not squirting out of one cylinder, first check and make sure that the 19mm fitting on top the pump is torqued to around 20 ft. lbs.  Do not over torque it.

Checkto see if you have fuel emerging now  at full throttle. If not, the piston in the pump is stuck. You will have to remove the fitting and check valve below if this is the case. At this point you can turn the engine to see if the piston in the pump actually moves up and down as the engine turns. If it does not, you have found the problem it is stuck in the up position.

Soak with penetrant and gently tap on top of the IP piston until it moves down. Use hard wood or soft metal and be gentle. If the piston does not move turn the engine since the cam below may be on the upstroke. Repeat as needed until in moves up and down on its own as you turn the engine.

Good luck and keep us up to date!

Joe Alexander
Blacklick, Ohio

[BaronYoungman]

Joe, that was very helpful but I have questions....when you take the 19mm cap screw that the line attaches to out there is a small hole that the fuel comes out of is that where you take the wood or soft metal and tap on? and when you take the rubber plug off of the front of the pump and use an allen key on the rack it should push back and then spring forward or back, if not does that mean that main rain rack assembly is stuck?

Bob

[ja17]

Bob, there is a check valve under the 19mm fitting. It must be removed first. It has some fine metric threads on the outside of it. Find some thing close enough to fit on the treads so you can pull the check valve out. MB has a special tool that you do not need. The threads on the outside of the fitting are not used for any purpose except to extract the valve so you can even pry a little on each side of the valve to dislodge the check valve. It simply pulls out, but the white seal around the perimeter of it tends to keep the valve stuck in place. If you do not have a metric fitting, try to fit find an SAE brass fitting close enough to grab the fine threads, .........should work fine..

Below the check valve you will see the small IP piston, it has a divot in the top and a notch at the edge, It is only about an 3/16" diameter. Around it is the cylindrical bore.  You may want to review the "injection pump tour" on this site to become more familiar.

Note...For those with 230SLs, the set up with the check valve is different than the 280SLs and 250SLs

Keep us up to date.

[wwheeler]

Hey Bob,

Here is a link to a thread about removing the check valve. I made a tool from hardware store parts to extract it. http://www.sl113.org/forums/index.php?topic=15754.0

I hope that helps.

[BaronYoungman]

AWESOME DONE ...Thanks works great now so have a back up (never know).  Learned ALOT! the rust had stopped up the check valve and there was rust inside of the cylinder also.. used compressed air to get piston out.  Thanks you everyone