MFI Have I fixed it?
 

Hi all,

Well I've spent the last three days freeing up my very seized MFI. It has been stood idle on the car for 9 years. On Friday only three pistons moved and the rack was solid. After soaking, cleaning, soaking, heating, easing so on.... I've managed to free up the other three pistons and now the rack moves relatively easy. With all three side covers removed I can with my fingers hold on to the top of one of the piston racks and rotate it so the rack moves forwards and backwards.

My question is, does the rack have a return spring, in that the documentation says to push on the rack with a biro or something and the rack should move back to the original position. Mine doesn't, if you push it moves easily but it does move back on its own unless you remove the side cover and move it yourself. If you look in the back cover, where you can see all the thermostat workings, I can only see one spring which looks like it should pull the rack back. This spring is only small and I can't see it being able to have enough strength to pull the rack back. If you were to put your finger in here and push on the rack (so your pushing into the pump) it moves and at the end it has a slight spring to it.

Does this sound correct? Does the pump need to be rotated for the rack to be pushed back? As at the moment I can't hold the MFI push and rack and rotate the pump. Oh what I give for another pair of hands. If anyone is in this neck of the woods (southern England)_grin.,

Basically the pump was rebuilt only 1 year before it was stood, it looks really clean and the rack moves freely, ie can be moved by fingers. Have I fixed it...

I know it hard to explain, any advice is much appreciated.

Alan.UK



:eek: SmileWavy

Sounds like your headed in the right direction.
Like I mentioned before I've never had a problem with mine so I've never been inside the pump.

I did however pick up an extra one at a garage sale Sunday. So I'll jump inside and see what I find.

Bobby

The rack must spring back to work properly. You will have to keep working at it until it does. It will spring back more easily if you rotate the pump while pushing on it but ideally this isn't necessary.

Sounds like its back to the work bench tonight then.

Also, when you turn the accelerator mechanism should that move the rack forwards and backwards. Moving mine doesn't move it at all. If it should its a good indication for me to know when it's working properly

Cheers

PS. Bobby, 5 pumps, 1 dollar each.... sounds to good to be true. That?s my kind of garage sale

Alan_UK

Alan - Yes the rack should move when you move the accelerator lever. If you push on the accelerator, the rack should move towards the inspection port (more gas).

Hi Alan,
I decided to edit mine whinny post. By the way I went back and got the rest of them from the guy that bought the whole lot. In case you may need a part down the road I now have 6 of them. (3) 69E's (1) 69S (1)71S (1) 72T. Also got a ton of linkage, throttle bodies and stacks.

When you get the pump going you should probably clean the injectors as well(ultrasonic). There's a great article on this in the Tech Articles. Then hook up the whole apparatus and run some fuel cleaner threw the metal lines that go from the MFI pump to the injectors by feeding the MFI pump fuel cleaner and turning the cog on the MFI pump.

Next hook up the injectors and turn the cog again and each injector should spray a nice conical pattern and emit a chirp at the same time.

I'm writing this procedure from memory of a previous post by Warren.

Who knows since the server is fixed maybe he'll be back on line so he can chime in. The slow server didn't affect you guys on the other side of the planet as much as here during its' peak usage.

Bobby

Along a parallel line of thought, how about "the care and feeding" of MFI? Let's say you only drive the MFI car occasionally. It might sit for 2 or 3 weks between drives. Should I use a fuel additive like Techlin (?) to reduce gum in the system? Any other tips or advice to keep the system in top shape?

Thanks

I don't think 2 to 3 weeks is anything to be concerned about. I
ve let mine sit for 2 to 3 months with no problem. If Techlin is the euro equivalent to Techron then why not. It will help keep the injectors clean regardless of the sitting.

Bobby

Thanks, Bobby. Same product, just a serious case of spelling deficiency!!! I have a ton to learn about my new baby.

bump

Bobby, you don't want to part with any of those 72T bits and pieces do you? I could use a couple spare TB linkages at the very least.

Hi Jeff,
No problem. I just need to sort the stuff out.
I'm going to see how many complete systems I can match up and then the rest will be for parts. It was just all sitting in a pile with parts robbed from the stuff.

Bobby

Hate to whine, but seems so unfair that you west coasters are fortunate enough to find garage sales like that.....