DDK - Die Deutschen Klassiker

I'm going to be getting my MFI pump rebuilt this winter, so thought I'd document it for future DDK'ers reference

I'm about to remove the pump using this guide found on Pelican :

Replacing a pump



Very important, rotate the engine to TDC of #4 piston (I full rotation past TDC of #1 piston) then another 40 degrees (there should be a mark on the main pulley). Then use a mirror to check the MFI pump to ensure the small mark on the pulley is lined up with the mark on the pump body.

Removing the pump is the easy part, except for 1 bolt that mounts the pump to the engine. This "devil" bolt is on the left front side and is covered by injector lines. To make it more fun using a socket extension is difficult because it doesn't quite fit with the injector stacks. After 2 hours getting that bolt out the rest followed including the fuel lines and oil tubes in about 30 minutes. Pick up some 1/2" and 1/4" plastic caps from the hardware store to cap the unit (especially the oil in tube, otherwise a bunch of oil will leak as you tilt the unit to pull it out). Lift and pull out the unit. Be careful not to let the drive belt fall off the cam pulley. While unbolting the unit I actually lost a bolt and it fell under the belt down to the cam pulley. I was able to fish it out using a screwdriver from the outside left hand side of the car (don't leave it down there).

Installing the new unit is even more fun. Fill the new pump with 300cc of engine oil (and cap with one of those 1/2" caps until you are ready to attach the oil hose). Make sure the crank hasn't moved. Compare the two pumps and make sure the teeth are absolutely identical when the marks a lined up. If not loosen the gear and rotate. When sliding the unit in place it is easier to make sure the belt is on the lower part of the pump and pulling it over the top as you complete the installation. Make sure the pump pulley mark is still lined up with the mark on the pump. Also make sure the belt fits cleanly in the teeth of the pulley without rotating it from the marks. Screw everything back on in reverse of the install process. Good luck with the devil bolt... I have yet to put it back in mine. "



If anyone has any other hints & tips before I start the job please post them [/u]

I had a bit of spare time today so started on this job.

So here is the beast



I started by following the guide above. The 6 photos below are from Mike Bainbridge to help with this thread

TDC :





Rotate to TDC No 4





Rotate 40degrees so FE lines up




.... I then checked using a mirror the red line on the MFI pulley shaft was lined up with the mark on the pump body.




Once this was done I undid all of the MFI fuel lines, followed by the feed & return rubber fuel lines.




Next I removed the oil lines ( feed & return ), removed the thermostat hose + disconnected the electrics.

Final job was to undo & remove all the mounting nuts & washers. This was pretty straight forward & even the 'devil nut' was done easilly ( Luckilly all these nuts had been undone only last year when we had the engine out )

A quick wiggle + removed the throttle linkage & out came the pump



in all her glory



I am draining the oil from the pump overnight, then packing it well & sending it down to Fred @ Tower Bridge Diesels

The story will continue ....

I look forward to reading about it James, tempted to get mine done. Are you checking/changing the injectors at the same time? My car runs rich because they're worn out.

I replaced all the injectors about 18 months ago and at the same time Mike Bainbridge got my throttle bodies & stacks rebuilt. basically my MFI system ahs been fully overhauled except for the pump. My old injectors were f**cked.

The reason the pump needs doing is Bob Watson couldn't set it up properly so we ended up making a compromise which allowed for correct fuelling at high revs but the low revs / small throttle openings suffered.

Looking forward to being able to drive in traffic smoothly ... as it is I have to drive through a flat spot

The last job to do after this is to sort out my overrun fuel cut off

James, I would be interested in why you decided to re-build the pump in the first place? Any particular symptoms?

Will

hot66 wrote:
The reason the pump needs doing is Bob Watson couldn't set it up properly so we ended up making a compromise which allowed for correct fuelling at high revs but the low revs / small throttle openings suffered.

Looking forward to being able to drive in traffic smoothly ... as it is I have to drive through a flat spot

The obvious symptom when driving is the first couple of mm's travel for the throttle pedal & the car would 'cough & splutter' ... the only way around this was to be a bit more aggressive with the throttle & drive through it. I think it is because the only way to get the fueling correct at the top end was to run a lean mixture just off idle. With it like this we managed 198bhp on the rollers so got the horsepower, but at the expense of teh described symptoms.

This is never a problem for most of my driving which is on country roads having fun, but if I was in traffic, in town, or had my wife in the car , then it became a pain.

Hopefully once rebuilt Bob can get a nice progressive fuelling dialled in

hot66 wrote:The last job to do after this is to sort out my overrun fuel cut off

Any following travel will be pleased

Look forward to hearing what difference the rebuilt pump makes

58A - 71E wrote:

hot66 wrote:The last job to do after this is to sort out my overrun fuel cut off

Any following travel will be pleased

I'll second that

hot66 wrote:The last job to do after this is to sort out my overrun fuel cut off

Want me to check out the speed switch for you James ?
Just post it down and I'll do that.
Least I can do for the work you put in for us all
Cheers
Tim

impmad2000 wrote:

hot66 wrote:The last job to do after this is to sort out my overrun fuel cut off

Want me to check out the speed switch for you James ?
Just post it down and I'll do that.
Least I can do for the work you put in for us all
Cheers
Tim

that would be great Tim ... Electrics are not my strong point Whcih bit do I need to send ? I know where the microswitch is, but which bit controls the overrun?

This is the best photo I can find quickly of the speed switch. Speed switch is the bit I'm holding !!

But I can check out both the speed switch and the microswitch if you'd like.
Tim

for reference :

http://www.ddk-online.com/phpBB2/viewtopic.php?t=14994



item 5 is the 'speed switch'

out of interest, I'm missing item 2 & item 3 and there is no wiring for them either . I believe item 3 is the rpm sensor ?

Does it matter if item is missing on a '73 car ?

I don't know if it is "5" or "6" to be honest. I think "5".
"3" is a tacho trigger device used on some cars just after the CDI was introduced. A '73 may well not have this fitted.
Speed switch, RPM sensor are seemingly the same thing, just different names.
Cheers
Tim

James


great idea for a thread, i want to do the same thing, and it seems a bit more sensible to dismantle, send to fred, retreive, refit and then go up to bob watsons, rather than having the car away for weeks and having to do 2 trips

I guess its best to ask Bob to check the injectors when he gets the car, rather than me do it myself (as I probably wont know what to look for anyway ?)

is there anything else I could/should do easily in this area whilst the pumps off ?

look forward to the next instalment

thanks
Jonathan