MFI thermostat mounting/adjustment 69's 911E

[SFE]

Hi all,

I've read pretty much everything about it in the forum but I still have some questions...

My car is a 02/1969 MFI 911E.
My injection pump is a Bosch part number 0408 126 002.

With my mecanics we did all the "per the book" adjustments and the car is running perfectly (thanks to NOS throttle body !).

But the car was still running rich at idle when hot (afR 10.5 or so).

We decide to remove the spacer between the thermostat and the body of the pump (red arrow) and we got immediatly a good value (afR 13.6) at idle engine hot.



On this picture we see a "cross shaped seal" just next to the spacer, this one was damaged and I did not put it back in place, is it a big deal ? (I'm wondering why is this seal for ???).

So know all numbers are good, I need to make sure the engine start is still acceptable when cold.

My intention is to remove some spacers inside the thermostat if the start is too difficult ; am I going in the good direction.

Thanks !

[911heaven]

Originally Posted by SFE

Hi all,

I've read pretty much everything about it in the forum but I still have some questions...

My car is a 02/1969 MFI 911E.
My injection pump is a Bosch part number 0408 126 002.

With my mecanics we did all the "per the book" adjustments and the car is running perfectly (thanks to NOS throttle body !).

But the car was still running rich at idle when hot (afR 10.5 or so).

We decide to remove the spacer between the thermostat and the body of the pump (red arrow) and we got immediatly a good value (afR 13.6) at idle engine hot.



On this picture we see a "cross shaped seal" just next to the spacer, this one was damaged and I did not put it back in place, is it a big deal ? (I'm wondering why is this seal for ???).

So know all numbers are good, I need to make sure the engine start is still acceptable when cold.

My intention is to remove some spacers inside the thermostat if the start is too difficult ; am I going in the good direction.

Thanks !

I had a 69' E Sporto ROW #0028 just sold last summer. Had 43k (km) original on the clock. Just sat for decades. I bead blasted my thermostat, took it to bits and meticulously cleaned all the individual parts, reassembled it as I dismantled it. My MFI pump I sent to Mark Jung. He didn't rebuild it, just recalibrated it, cleaned my injectors and sold me a used one, for one of mine that was dribbling (75 bucks, 750 for the pump work). It all worked great after that! I'm no pro, just some experience with this. I bought a complete engine gasket rebuild kit, but only used pieces here and there, never took the motor out of the car. Fixed about 12 oil leaks though.

I remember the old saying right rich, left lean on the throttle body fuel enrichment/mixture screws. If your running rich on hot motor, it could possibly be that. You may be way ahead of me here already, just something you made me remember.

Good luck! I had a thread on this car here, maybe some pix in there of my thermostat don't remember.

bernie

[ed mayo]

By removing that gasket you moved the thermostat inward leaning the mixture.

[356RS]

Just a small correction but that is a metal spacer/shim not a gasket. About 1.5mm thick for the early MFI and 2mm on the later pumps. All part of the thermostat adjustments.

[911heaven]

One thing I did before getting onto the pump issue was to take the thermostat completely out of the equation before entering the dragon (which I though might be a very expensive route I.e pump rebuild).

It was a trouble shooting idea of mine and I knew it would cost me extra and it did. I ordered a manual thermostat control gizmo from Henry at Super Tech which one controls by lever and cable from in the cabin. In the end I was still running rich, so I knew it was the pump. I resold that part here on classified forum used but like new, lost a couple hundred in the end, but at least it worked for me to trouble shoot and get to the dragon (pump in my case).