MFI Baseline settings

[GDSOB]

Ok, I searched through all the MFI threads and couldn't find any reliable information on the baseline settings for the adjustment screws.

That would be the idle and part throttle adjustment number of clicks out from screwed all the way in. I'm fixing ignition issues that were hidden by pump adjutments. Now I'm starting with the CMA and would like a reliable initial setting.

[30westrob]

I do not believe there’s any baseline settings on the pump. You start by carefully observing rich or lean running and start making adjustments from their. I always write down my observations and adjustments.
Rob

[356RS]

What engine are you working with? Let me know along with the cams, compression, port size and I can give you a baseline to start with.

[cmcfaul]

An afr meter makes all the difference.

Chris
73E

[GDSOB]

Mark,

Stock 2.2E mfi, stock everything except for hollowed out muffler dual outlet with removable baffles.

I plan to install an AFR Gage, but need to get it running well enough to get it somewhere with a CO meter.

Thanks in advance

[cmcfaul]

Will run good rich. Will make power lean. Set it up rich to get it going then dial it down. Too lean will cause undetectable detonation and eat the compression ring. Again afr meter is your friend.

[356RS]

Garth, The correct way would be to remove the pump and on the test stand you would set the main rack movement for 4.5 - 4.7mm @ 400 pump rpm at zero throttle; 4.6 - 4.8mm @ 750 pump rpm with 8.3* throttle; and 4.8 - 5.0 mm @ 2000 pump rpm with 29.5* throttle. But you want to get your car going without removing the pump and need a baseline. So, For a 2.2E set the idle at 5 1/2 turns out from bottom; Mid range 3 3/4 turns out from bottom; Hi range 2 1/2 turns out from bottom. Now if the main rack has not been adjusted all over the place the engine should start and idle somewhat. Next you will need an AFR meter. If the "main rack" has been played with, you will need to get the idle AFR set by adjusting the "Main Rack" till your around 12.5 AFR. Normally you would use the Idle mixture screw on the pump, but for this we want the governor springs set as close as possible for the E space cam and bring the Main Rack back to a good starting point. Make sure the engine is all warmed up and the thermostat is getting hot/warm air from the left heat exchanger.
Give it a test drive and check AFR's under some loads. Fourth gear up hill to 6000 rpm. Check cruising AFR's @ 3000 rpm 5th gear.
If your lucky this may get you close to normal running. Get some AFR numbers now and lets see where we are.

[GDSOB]

Thanks Mark, that was just what I was looking for.

I am a little confused. I am only aware of the idle mixture adjustment and the part load which would be the main rack, so, I'm not sure of the difference between the mid range and high rpm adjustments. Are those the screws on the governer? My hope would be would be the base setting for the idle and main rack without playing with anything else (yes, it has been played with and I am not going to touch anything until my ignition parts arrive and am sure of timing) It sounds like more adjustments are required than just those two.

[356RS]

Sorry, I was assuming you meant all the governor spring adjustments. You can still set the idle adjustment to a base line then with your AFR meter adjust the main rack for a good idle and hope the rest of the governor spring settings are good, just have to line up the main rack for the rest to blend in. This method is not the correct way to adjust things but should get you close. The best way is to have the pump on a flow/calibrate bench and set everything up to spec.
One more thing: The main rack has a base line setting but cannot be done without parcel disassembly of the MFI pump. If you turn the main rack adjusting screw inside to far counter clockwise it will fall off along with a few other parts.

[GDSOB]

Went to cars and coffee this morning and the car is generally running well, except...

I've had an ongoing issue with the the idle. After warm up, it settles to an idle around 850 rpm as long as the throttle is not touched. After a few revs, it idles at 1900 rpm and stays there. However, if I turn it off and restart the engine without touching the throttle, it's back down to 850 again. Very repeatable.

The thermostat washers are correct and clean so the warm up circuit appears to be working. The microswitch tests good also. There is no binding on the linkages either.

Any ideas what to look at next?

[47silver]

the idle on our 72 T was staying high ~1900 rpm.
if we put it in gear and let out the clutch to slow down the motor the idle woudl return to 950.

We checked:
throttle linkages:
Rack on mfi.
Micro switch setting.
these were all good.
We removed the distributor, removed the points and on the recommedation of a pelican dropped it in toa vat of new WD-40 for a couple of days. We removed it, blew it out as best we could and dumped oil into it until it could not take any more (I believe Warren Hall recommended to do this).
We installed it and the hanging idle was solved.
After cycling through a couple of distributors on this motor I think that this is mechanism causes a lot of problems in these cars.

[GDSOB]

Sounds familar...

I replaced the points with a Pertronix Ignitor recently with no idle improvement. It was suggested that the distributor advance springs were weak which makes sense that the idle would kick up, so have some new parts on the way. While the distributor is out I'll try the WD & lube treatment. Hopefully that finally solves the problem.

[Rosco_NZ]

Get a 123 Ignition distributor & be done with the mechanical springs and plates

[47silver]

My settings on a 72t pump are:
Main rack: turn full clockwise to stop then out ccw 63 clicks or 5 full turns plus 3 clicks.

Idle: turn clockwise to stop. Go ccw 5 and a half turn o 33 clicks.

May need a click or 2 either way my dual afr meters are reading a bit rich at idle but have not had time to tune it further.

[g3ngs]

Originally Posted by 47silver

My settings on a 72t pump are:
Main rack: turn full clockwise to stop then out ccw 63 clicks or 5 full turns plus 3 clicks.

Idle: turn clockwise to stop. Go ccw 5 and a half turn o 33 clicks.

May need a click or 2 either way my dual afr meters are reading a bit rich at idle but have not had time to tune it further.

I know this is a couple of years old now, but MFI fiddling never goes out of fashion...

@47silver what AFR values did this achieve with those settings at idle, highway cruise and wide open?

[Rosco_NZ]

No one mentions in this thread that 72/73/2.7RS distributors have vacuum retard. So when throttle is closed, 10 deg timing is pulled out via vacuum. I think this really helps pull engine back to idle.

[47silver]

I ended up sending the pump to 356rs and he rebuilt it and set it up. Runs good