MFI Pump - removal, rebuild & re-fit

Lightweight_911 · Post by **Lightweight_911** » Fri Nov 28, 2008 2:21 pm

5 = speed switch

6 = relay for 2-stage heated rear window

2 = relay for single stage heated rear window

3 = RPM sensor

In any particular car you would normally find either 2 or 6 depending on which type of rear window was fitted.

hot66 · Post by **hot66** » Fri Dec 12, 2008 1:48 pm

bit of an update

The MFI pump has been fully rebuilt by Fred @ Tower Diesels and should be with me next week. No horror stories thankfully , Fred reckoned it just needed a good freshen up.

Tim has my 'speed switch' and has reported it wasn't working , which explains why I was chucking out unburnt fuel on the over-run.

Photos to follow

Mick Cliff · Post by **Mick Cliff** » Fri Dec 12, 2008 3:43 pm

hot66 wrote:....which explains why I was chucking out unburnt fuel on the over-run.

Salvation for the Northerners looks imminent

210bhp · Post by **210bhp** » Fri Dec 12, 2008 4:20 pm

Be interested to know your new mpg when you get things back together James.

Regards
Mike

hot66 · Post by **hot66** » Sun Dec 21, 2008 3:01 pm

the pump has returned

Not had time yet to unwrap it ( saving that for Xmas day

) , but for those that are interested, Fred leaves the 'adjuster' cap head screws loose on the belt pulley.

If I have time over the holidays I'll get the pump mounted back & then go through the proceedure of priming the fuel lines etc

hot66 · Post by **hot66** » Tue Dec 30, 2008 9:47 am

for reference, interesting thread detailing the internal workings of an MFI pump

http://forums.pelicanparts.com/showthread.php?t=386414

hot66 · Post by **hot66** » Tue Dec 30, 2008 11:08 pm

managed to grab some hours in the garage today.

Reassembly begins

I started by filling the pump with 300 ml of engine oil,

Mike Bainbridge has been very helpful & given me some pointers & advice, the 1st bit being it will be better to remove the left hand throttle stacks ( not the bodies ). With the throttle body stacks removed I also removed the left hand fuel lines to help with access.

I rechecked the positioning of the engine to confirm it hadn't moved from the position I left it when I removed the pump, then rotated the MFI pump pulley so the alignment marks were 'aligned' and then refitted the pump, ensuring the MFI belt slipped onto the pulley. I also loosely refitted the oil outlet pipe to prevent any oil spillage.

& yes that is spilt blood

With the pump in position & the belt on the pulley, the pump timing needed to be rechecked. You will need to use a mirror for this as it is impossible to see otherwise. The pump was returned with the adjuster screws loose, so a bit of fiddling around was required until I was happy ( the screws can be seen in the 2nd photo below, within the pulley)

I then locked the pulley into position using an allen key on the socket head cap screws locating the pulley to the pump shaft ( difficult to do due to lack of space ! .... I ended up only tightening 2 of them & tightened the 3rd later when I was in a position to rotate the engine )

Next job was to adjust the MFI belt tension. This is done simply by moving the pump 'left or right' on its mount ( it has slotted feet )

Mike suggested : " the belt do's not need to be like a cam belt tight, as long as it is not that loose it will hit the covers " . Using a screwdriver I levered the pump across to the right ( in my case as far as I could get it) and nipped up the mounting nut nearest the pulley. ( photos from Mike bainbridge)

Mike also highlighted the importance of ensuring the pump body was running square with the belt to ensure the belt did not 'run off' the pulley when rotating. I checked the body was positioned correctly, then the rest of the mounting nuts were tightened.

hot66 · Post by **hot66** » Tue Dec 30, 2008 11:12 pm

Back in the car

With the pump body fitted back, the pump timing and the alignment all sorted it was now just a matter of refitting the throttle stacks & injector lines. Once these were back together I reattached the oil lines, fuel lines & throttle linkage

All thats left to do is bleed the fuel injection lines and start her up ... but thats for another day

BTW, I have updated the 1st post in this thread with more photos

hot66 · Post by **hot66** » Fri Jan 02, 2009 4:12 pm

Today I got round to finishing the job

Before I bled the fuel through, I checked again to ensure the pump timing marks were aligned correctly. Next I rotated the engine by hand a couple of full rotations and again back to FE mark after TDC on No 4. This was to confirm the MFI belt was running 'true' and again to confirm the pump timing was correct ( which it was

)

On to bleeding the fuel lines .......... for this job I kindly had the help of my wife

.

To start with I loosened off all the fuel lines from the injectors.

I then got my wife to turn the engine over on the starter motor to pump the fuel through. After about 8 turns of the motor there was no fuel coming through

It turns out it takes a lot of turns of the pump to get the fuel pumped through, so eventually with a bit of patience ( & semi starting the motor on the cold start circuit) I had fuel at the injectors on the left bank ( shorter lines )

I attached the fuel lines back to the injectors, but not tightened yet. With my wife turning the engine over again on the starter, I let fuel bleed out of the lines & nipped up each one whist the fuel was bieng pumped.

This was repeated on the right bank.

Once all was done, she started straight away

My pump has been rebuilt to stock 2.4S spec with stock 2.4S settings. Fred reckons it'll be fine to run 'out of the box' , but I'll be running the car back down to Bob Watsons rolling road as soon as I can to get it fine tuned. It'll be interesting to see what the power/torque curve will be like now.

I had a quick blast up the village and all is well. Not sure if it is my imagination, but straight away it seems stronger in the mid-range.

Hope this has been of help to some of you

.

58A - 71E · Post by **58A - 71E** » Fri Jan 02, 2009 4:25 pm

hot66 wrote:I had a quick blast up the village and all is well.

Good stuff Mr C, but have you had anyone follow you yet to confirm all is well for following traffic

Love threads like these

impmad2000 · Post by **impmad2000** » Fri Jan 02, 2009 5:05 pm

Excellent stuff. Dare I assume that you've got the speed switch back yet ?
Tim

hot66 · Post by **hot66** » Fri Jan 02, 2009 5:40 pm

Tim, I got the switch back, many thanks for your fettling with it

The switch is installed again along with the microswitch, but I'm not sure if the 'circuit' is working or not. If I press the microswitch when holding the revs at around 2000 nothing happens. I know the speed switch & the microswitch work ( thanks Tim

)

Once I have everything totally finished ( I still have some fuel lines to replace on the cold start circuit ) I look into it all in more detail

Ferry Man · Post by **Ferry Man** » Fri Jan 02, 2009 5:59 pm

hot66 wrote: for this job I kindly had the help of my wife...

I then got my wife to turn the engine over...

With my wife...

Great work James.

Although I'm not sure who did all the work....

jtparr · Post by **jtparr** » Fri Jan 02, 2009 6:05 pm

great thread james
glad it all worked out

jp

impmad2000 · Post by **impmad2000** » Sat Jan 03, 2009 9:14 am

hot66 wrote:The switch is installed again along with the microswitch, but I'm not sure if the 'circuit' is working or not. If I press the microswitch when holding the revs at around 2000 nothing happens. I know the speed switch & the microswitch work ( thanks Tim )

Pull the wire from the solenoid (On the MFI Pump ?) , and put a 12V bulb to GND on the connection. The bulb should light under the condition you describe. Sidelight/dashboard bulb will be OK.
Touch a 12V feed to the solenoid on the MFI pump and see if that does something.
Tim