Continuing IP repair

[Fano]

good day all,

I trust you are all well. I am ok, but I am deveolping a headache with my 280 SE Injector Pump: I had started working on it thanks to a lot of help from Joe a few months ago, but I had to suspend the work because of an expensive problem with my distributor shortly after. has been resolved, and I have begun working on the IP again.

My mechanic and I got the car to start a few times, but every time it started it would die after 2-3 sec. Eventually this past week, it failed altogether at starting. After going through Joe's IP tour, I got the shaft at the front of the pump to move back and forth and  return to its place of rest (about half an inch) under own spring action when pushed. So, presumably then, the rack is free. I'd previously removed the check valves from the top of IP fuel outlets, doused with carburettor cleaner, and deep penetrant. The plunger pistons were all moving freely inside the cylinders.

This week after the engine failing to start, we took the fuel lines off the top of the IP, and cranked engine to see if fuel was coming out. We found that from fore to aft, only no. 1, 4, and 5 were pumping fuel out, and weakly at that. The other 3 pushed nothing out at all. The other 2 critical issues are leaks: Therere's a large amount of fuel coming out of the shaft in the front (The one you have to push to test if rack is free). There also seems to be fuel mixing with oil. There's a mixture of oil and petrol leaking out of a small hole in the bottom of the transmission bellhousing.

I've printed and filed all the info from Joe's tour to see if there's any sloution to the problems thus far. My pump is the newer one with circulating oil, and I believe it has no dipstick. Any advice? Also, I just want to confirm that there's only 1 fuel pipe from the tank feeding the inlet pipe to IP; and that There's also only 1 return line going from the pump back to the tank. The reason I ask is that there's what seems to be a fuel pipe running under the car from the tank, right next to the INLET/RETURN pipes. It is at present unused with nothing connecting to it.

Thanks,

Fano

[ja17]

Hello Fano,

It is possible that your pump is free now and you just did not crank the engine long enough to prime all the pistons in the IP. You may want to try check for fuel delivery again first. Remove the spark plugs, coil wire and move the IP linkage lever to full throttle and see if you can get fuel from all fittings on the IP by cranking the engine again.

If you cannot get fuel from all six pistons you may still have some plungers stuck in the pump. You may have to remove the IP lines again, pull the check valves and actually watch all the plungers move up and down.

After everything is free, re-install the check valves, torque the fittings on at 18 ft. lbs. Remove the spark plugs, dis-connect the coil wire and crank the engine until you see fuel emerge at each fitting. Push the IP linkage lever to full throttle while cranking. Once all fittings show fuel (Only tiny amounts of fuel is injected on each stroke so do not expect to see a lot of fuel at the pump)Reconnect the metal lines and then loosen them at the injectors. Crank engine again with IP linkage lever on full throttle. As each injector fitting show fuel tighten it down until all six have been done.

Bite the bullet and change the oil at this point. Install a fresh set of spark plugs and fire it up. Make sure the warm running device (WRD) on the injection pump is not stuck or you will still be running rich.

Save your original spark plugs for clean up and re-use in the future if you like.

If your IP rack  has been stuck then you may be contaminating the oil with excess fuel.  As the oil thins from fuel contamination it looses its viscosity and new leaks spring up as you have noted. The oil also looses its lubrication value (only 5% contamination Maximum) before your oil is ruined.


The third fuel line on these late W113 cars is actually a fuel vapor line venting into the engine block (USA emission regualations).


Keep at it!

[Fano]

Hi Joe,

Thanks ever so much for your patience and advice. I'll keep at it. I'll let you know soon as I can. Most likely only going to be on saturday or sunday.

Till then, keep well.

Thanks again,

Fano

[ja17]

Hello Fano,

Make sure you torque those six IP line fittings to 18 Ft. lbs.  If these are not tight enough those IP cylinders will not pump fuel.

[Fano]

Hi Joe,

Sorry for the delay in response. I only got around to doing the work yesterday on the IP. I got all the check valves and fittings off, doused in carb cleaner and penetrant and allowed to soak. Then I disconnected spark and coil wires and cranked the engine. The 1st five plungers were moving up and down quite nicely, but the 6th one was very slow in moving up and down, so I left the mechanic's workshop having soaked the plungers again. I'll return tomorrow to try and get the no. 6 plunger moving like the others.

Once all the injectors have got fuel delivery, I'll move onto the CSV and clean as required to ensure non-rich running.

Thanks,

Fano

[Fano]

Hi again Joe. Sorry for the delay in response again. We were busy las week with funeral arrangements. My grand dad passed away on the 20th. We manageed to give him a nice send-off though.

As for the IP, I am very grateful and happy to announce that we now have delivery to the High pressure pipes. I did everything the way you'd asked me to. It worked well. The car isn't starting yet though. There seems to be a problem with the spark. We are working on it.

The only worry I have is the manner in which the fuel is exiting the HP lines. For most cylinders, it's squirting out, but the mechaninic says that the flow isn't strong enough. He reckons it should be a more forceful squirt. I'm not sure if it's supposed to spray (like a mist) or squirt, and at what force it should be doing this. Before we put the connected the HP lines back to the pump, the fuel wasn't squirting either when we cranked the motor. the were small qtys's of fuel exiting at each fitting, but it wasn't exiting with a forceful squirt like a diesel IP normally does. does this sound right?

Thanks for all the excellent help and information.

Fano

[ja17]

Hello Fano,

Unless you have the injectors connected to the lines you will not get a "cone mist squirt". Only a very small amount of fuel is delivered with each stroke of the plunger. Quite a bit of cranking is required before all the lines are purged and pressurized. Crank at full throttle, once all lines are delivering fuel, install a fresh set of plugs and start it up.

You should also check the fuel pressure and volume from the electric fuel pump if you still have starting or running issues. You can take these readings by dis-connecting the metal fuel line going to the intake cold start valve and hooking up a gauge.

[Fano]

Hi joe

Been working on the car the past week. A couple of things to report. Firstly: YEEEEEEEHAAAA!!!! EUREKA! We got the car to start. Joe, I believe the modern hip-hop lingo would address you as 'YOU'RE THE MAN!'. Thank you very much. You are the man indeed.

Secondly though, When idling the car idled a little rough and high , but I'll have a look at the linkage tour, and the tour about the load adjuster screw on the rear end of the pump, and try sort the idle out. If I'm not mistaken, that's the screw for adjusting idle rpm.

You'd be amazed howmuch liquid (Mixture of oil & petrol) came out of the oil sump when we drained it..12.5l in total. Its viscosity was like water. I can't believe howmuch fuel contaminated the oil.In fact when we started the car, the stuff was sparaying out of the oil cap; and it was closed!

I'll keep you posted on the progress. Should be doing more work this afternoon as well. I'm very grateful for the all the great help. Thanks again.

Fano

[glennard]

Ah, yesteryear!  40 years ago I got a 56 220SE pontoon convertible with the 2 plunger pump.  Poured Quick start, gasoline, you name it into it, etc.  Finally filled the crankcase.  Same thing.  Virtually pure gasoline.  Wondered why it had no compression.  Changed to oil instead of gasoline for lubricant.  Compression came back -and it ran.  The Learning Curve!

[ja17]

Hello Fano,

Congratulations, I figured you were close but just needed a little more effort to bring it to life. The internet is quite amazing. We can sit at our computers many thousans of miles away and help youfix your Pagoda!

Yes, linkage set up is critical before other adjustments are undertaken. Keep us up to date.

[66andBlue]

For those who like to, or need to repair injection pumps life may have become a bit easier. Bosch is selling previously unreleased old documents on pump repair and other info:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=120289498714

[Fano]

Thanks again for all the invaluable input gents. It really does go a long way. Since last week, we have discovered that there is a misfire in 3 cylinders. I have since replaced old plugs with 6 new NGK BP6ES. It improved roughness of the idle slighltly, but for the most part the misfire is still alive and well in atleast 2 cylinders.

I have since ordered a new set of HT leads to attack the problem. At this stage I don't think the misfire is due to fuel starvation, as the misfiring cylinders do deliver fuel; and when we do take the plugs out to inspect them, they are wet..I think with fuel.

The internet is amazing indeed..it is apparently going to succeed at getting this lovely specimen of true solid Duetsche engineering back on the road.

I'll keep you posted. Thanks again everybody; and Joe in particular.

Fano

[glennard]

Get it leaned out.  Min fuel at 800 rpm-squeeze air back 50 to 750 rpm.