mfi pump- which one do I have? How to adjust?

[TR]

Hi can any one tell me the exact lenth the rod protrudes from the thermostat in a 2.7RS spec at running temp?

Oh, and how may bimetal washers and in what order?

thanks

Terry

[TR]

Hi dicklague

I measured all the linkages, the one from the pump is about 13mm at 14 it doesn't want to run very well. I took the old linkages off the 2.2 from the throttle bar to the bodies and put them on the 2.7. the car runs 100% better but idle has dropped to about 200 rpm, if that.
It will stall without the hand throttle.

good news is it is drivable at low speed , bad news is I don't have the tester to measure and balance each throat of the stack.

tail pipes also gone fron beige /camel brown to sooty black--bad news I guess.

Fix one thing and a host of others opens up.

Test equipment would be good but if i don't know what I'm doing with it I'll just go round in circles.
Time to take the car to the local Bosch injection guy. He's old school but hasn't worked on mfi for a long time. A few weeks ago he suggested I just drive it a while let the new motor settle in and then check and measure and adjust as needed. At least he's got the right approach.

I filled up with the third tank of gas today but didn't add any octane boost--maybe thats also why I 'm getting darker deposits.
If the linkage from the mfi pump is supposed to be 14mm what are the other two lengths supposed to be?

Cheers and thanks for the help.
Terry

[356RS]

Terry, I would like to help you out on some of your questions but I,m out of town right now and some of the specifications you requested need to be more accurate than my memory can provide. I have the data on the thermostat rod length for the 019 pump back at the shop but I can tell you there are 25 bimetal disc pairs in the thermostat. More important is the number and size of the solid discs on the end of the rod. These other discs set up the amount of fuel needed for a cold start on the 019 pump for the 2.7 RS engine which is a little different than the other pumps.
The rod length of 114mm connected to the pump throttle lever is very important because it sets up the proper throttle angle relationship between the pump and throttle bodies. Of course the linkage on the throttle bodies has to be set up correctly before this can all work correctly.
I'm sure there are many on the board today that can answer your questions. Lots of great help on this board.

[TR]

Thanks 356RS

I will plod along, I'll ring the Porsche dealer see if I can get the parts guy to give me the right number of discs fot the thermostat.

the fuel shut off solenoid might be Ok as that was on the pump when it went for a rebuild, I would have expected them to set the rod lenth if it needed it.

Cheers

Terry

[TR]

been plodding along

raised the idle to around 850-900. The screws were all over the place some went two turns to match the others. The car absolutely powers. I used a flow meter to try and match the stacks. got the right set ( thats facing the engine from the back) all pretty balance but the air srrews have almost no effect on the left side. They are all pretty even but don't match the right side at all.

Turn the screws in and it falters, turn them out and not apparent effect. They would bave fallen out if I kept going.

Still a little popping and the odd gurgle.

The left side you can hear an obvious ff-t ff-t ff-t sound. Injectors are all new , tank new, lines cleaned and new filter.

I want to get the left running like the right side as it's smooth not faltering.

Still looks a bit rich at the pipe.

Time to go to the shop I think. hook up to the test equipment.

Any more ideas would be good.

Thanks

[356RS]

Terry, Glad to see you have a flow meter and you have the right side set. How much of a difference in flow meter readings is there between the left and right? When you are checking the flows do you have the linkage arms, left & right, removed from the main crossbar throttle arm?

[TR]

Hi 356RS
Flow meter is a bit primitive, borrowed it from a young guy with a bastardized 912come 911 around the corner. The meter only has three divisions.
I have ordered a new one.

First
Three stacks on the right are spot on in the middle of the gauge, at level 2. The indicator jumps around a bit but you can clearly see they are all even.
Other three are barely at level 1.

Second
No--didn't disconnect the linkages, should I? Ill try that this morning.

I guess, what you are going to say is, set it when the throttle bodies are in a relaxed state and then re adjust the linkage on the bad side to match the good. I'll try that too.

I pulled four of the plugs yesterday front cylinder right side was camel brown colour looked textbook excellent the next four were black sooty. I didn't pull the last two as it was getting dark but they are on the bad side so I suspect they are a bit fouled as well. Think I also need another bottle of octane booster.

Also pulled apart the thermostat. 25 bi metal disks, two thick and one thin spacer. All works perfectly. Came from a 2.2E but compares with the 2.4 specs when you heat it up rod shortens to 17 mm, It appears to work properly.

Attached are two photos. The one good plug and the motor as its set up.

Whilst running it without the filter it also seemed to run better. i do have some K&N filters but for some reason the filter element has never sat properly in the groove, also the element fowls the barometric regulator plus does not have the cold start fuel circuit. Might drag them out today and look at them.

[356RS]

Your on the right track Terry. Let us know the outcome with the linkage removed. Reading plugs from an engine that has been at idle will not give you an accurate reading but I guess at least they should be all the same color. Mine are close to black with the MFI I run.

[TR]

Hi 356RS
back again.
Well after a few hours in the shed tinkering I have now managed to get all the air flows at about the same level.
I disconnected the linkages to the throttle bodies and let the engine idle on its own. as soon as you tried to in crease the idle on the left bank it stalled, that was odd because it was the side which appears to be spluttering. I was trying to just open the butterflies a bit---didn't work.

I wound all the air screws in. some went more than eight full turns others only four. it was obvious they had no effect at all on the enginee. I then wound them out about four full turns each, thought that was about right as i had read it in a post.

I tried to re attach the linkages but idle went up to 1500. disconnected and lengthened the rods. then took it for a drive and experienced the lag at 2500-3000 2nd gear.

Turned the linkage end one full turn each and reconnected again the car is drivable again with a small hesitation. I'm not sure if this is due to the fuel shut off solenoid, i did have to readjust the micro switch stop because is wanted to back fire a bit on deceleration.

It is such a fine line between a total cock up and absolute power that is in quite unbelievable. i can see why many people get the sh-ts with it. luck i never give up.

Tail pipe is back to camel brown now, hope it's not too lean, I'll see how rich the exhaust looks on start up this morning.

Might have to wind in one linkage end one full turn again. also think another set of throttle bodies and brand new linkages are on the cards. There does seem to be about 2mm play across the tree butterflies
all in all I'm very happy

Big Thanks

Terry

[TR]

Does my one light coloured plug look too lean?

[Flieger]

No, but idling is not the way to read plugs. Put new ones in, go for a spirited drive and shut off after accelerating hard for a second or two, coast to a stop, and pull plugs.

White would be too lean. Light Brown is just right. Darker brown than yours would be rich. Black is probably oil.

[TR]

Hi
mondat here and about to go to work.

You can go from brown to black on the plugs with just a few mm of adjustment in the linkages from throttle bar to the butterflies. Unless you motor is really worn the black is just really rich isn't it?

My motor is new so can't be the oil when black or iIwoouldn't be able to obtain light brown with the minor adjustments.
does that sound right?

Next week end for more adjustments--must order the Co meter to really know whats going on.

cheers

Terry