MFI pump imposter!

[psarmany]

Just pulled the engine from my 1970 2.2E (Memorial Day weekend) and have been slow disassembling it since then. My intention is a complete overhaul of the motor and to return it to it's original state. Well after getting the MFI pump off the motor and getting it ready to send to Gus I was shocked to find it's a 2 liter pump and not a 2.2 pump! The part number off the top of the pump is 0408 126 006, which according to the "Check, Measure, Adjust" manual is a 2 liter E pump. It would seem like the pump I need is pn 0408 126 010 2.2 liter E pump. On to my questions...Should I find a 2.2E pump or can Gus set this one up to work with my motor? What about originality if my current pump can be used? Also on the front of my throttle bodies are small vacuum fittings which the PO plugged with a vacuum line and a screw (actually crimped one), I didn't think the 2.2 liter motors had vacuum advance/retard like the later 2.4 liter motors had...any thoughts? Thanks in advance, Pete

[304065]

An easy way to tell a 2.0 MFI pump from a 2.2 is the number of solenoids. The 2.0 has two, the 2.2 and later only one (for overrun cutoff).

Gus will certainly be able to tell you if the pumps are interchangable-- I wouldn't think the body of the pump would matter, only the profile of the 3-dimensional space cam inside.

The stacks on my 2.2 also have bright, cad-plated screws plugging some holes at the bottom of the stacks.

Is this the vacuum line, #27?

[psarmany]

John, Thanks for the reply, I will be calling Gus tomorrow to find out what he can do. The enrichment solenoid is what caught my attention although I can't believe I didn't notice it in the last two years (when I bought the car)! Item #27 in the diagram you posted is exactly what I was referring to, yours are plugged as well? Why would Porsche put them there if they weren't intended to be used?! Pete

[304065]

Peter:

My guess is they are vacuum ports used to control the ignition advance. This is further borne out by the fact that they are on the "inside" of the throttle plates. I have a mechanical advance distributor that was fitted along the way, so presumably the ports were plugged at that time? But your post gives me an idea. . . I disabled the cold-start mechanism on my car, and will explore whether the vacuum ports can be used to locate squirters for a cold-start system much like on the 2.4's. . .

I sure am glad there's a guy like Gus still around- - my mechanic went to school on MFI in the late '70s and I try to pick his brain as much as I can to keep this knowledge alive!

JFC

[jluetjen]

An easier way to rig a cold start with a 2.0 MFI is to run a switched 12V wire to the cold start solenoid. I did it on my car and I've heard is similar to what the factory used to do on some of the race/rally cars.

In the case of my car, I spliced a wire from the start circuit at the ignition switch and ran it to an unused switch on the dash. From there I ran it back and connected it to the cold start solenoid on the MFI. When the switch is closed the solenoid gets 12 volts as long as the starter is engaged. This 12v pegs the MFI's rack at full rich and the engine starts with just a couple of cranks. It's much neater then pouring raw fuel down the stacks.

I just make sure to open the switch after starting the car since trying to hot start the motor with the switch closed will result in the motor flooding.

[304065]

John,

Thanks for the reply. My '71 doesn't have the cold start solenoid, only the overrun cutoff solenoid. . .I actually have a '69 pump gathering dust (actually waiting to be reborn in a GT-class car), but I don't know whether that solenoid can be added to the later pump.

But I like this idea, and have also seen it some early, cool cars! A big red button with "COLD START" on it next to the ignition. No matter what happens I'm going to get me one of those, and put a label that says, "KRAFTSTOFF !" or something like that. . .