Converting MPi to twin HS4

[nick rogers]

This is so far out of my experience that i'm hoping someone on here has had experience of it. A customer of mine abroad is determined to carry this out. I have advised on several fuel-related issues but can't offer any help on spark or engine management questions. I would be grateful for any help and will happily phone anyone who has info for a chat. If you know of anyone or better still, have done this yourself please contact me.
nick(at)min-e-bitz.co.uk or 07766686982 or 0114 2554630.
Ta, Nick.

[Sean1380]

He would probably have to run an aftermarket ECU to run the spark Nick, something like the cheap as chips mega squirt, or better still, DTA.

Prob wont be as smooth as the std Rover setup, lets be honnest, 2 hours on a dyno setting up a very basic ECU can never come close to the hours spent developing the OEM stuff. I run a 1999 Daewoo Lanos that i have Turbo charged, and run a Dictator after market ECU - it works, produces the power, BUT its a real pain in the a$$ as a daily driver as it doesn;t have a stepper motor controller -so when the head lights go on, the idle drops, when i put the indicators on, the idle drops, when the sound goes on, the car stalls

So unless he can get the Rover ECU to work without the injectors all plugged in, then his only option is the other ECU.

[mk1]

May be worth giving Fishy a ring Nick.

[guru_1071]

nick

its actually easier than you think

your customer will need a aftermarket ecu (anything from the diy megajolt, to the more ready made sc stuff - theres plenty of choice), a toothed wheel and pickup holder (again, prices vary the diy stuff to stuff that will just bolt on), a coil pack (i guess the mpi may work) and a map sensor.

this will let him run anything on carbs - the original ecu will just be left - he will probably need this to run the temp guage etc

[nick rogers]

Thanks guys, I knew I could depend on you.
Mark, I've tried to reach Fishy re another issue but thought he must be away ?? I'll try him again.
Anyone got anything else to add ? I'm grateful for any help.
Nick

[dhenry]

I once converted my mates awful spi to a single SU carb. It was very straight forward. The ECU was ditched and in its place was a regulator. I swapped the dizzy out for a standard points dizzy and bobs your uncle. The temp gauge didn't work after the conversion but the car ran so much better. There is an article on this conversion on the internet somewhere. This is what i used when i did it. It was a few years ago now but if i can find a link i will post it. I am sure the procedure will be similar for spi and mpi. Good luck.

Daniel

[guru_1071]

dan


the main problem with converting the mpi to carbs is that it doesnt have the provision to run a dizzy, so you have to run a trigger and an ecu to control the spark.

the other problem is that the water temp, fan controls, oil light etc etc are all run through the main ecu so this needs to remain to service the needs of all these external controls

all solvable with thought and money, but far harder than the easy spi (which ive always found to run very well on the injection)

[dhenry]

I forgot, we also changed the fuel pump for mechanical.

Ah, thanks guru. I wasn't aware of all the changes. Still, an engine is an engine so will be quite possible if well thought through. My mates spi had some serious fueling problems that we couldn't get to the bottom of. In the end we swapped to carb. It was a lot of fun doing the work and we both learned a lot. Cheers,

Daniel

[nick rogers]

Thanks Daniel for the input. I know the SPi conversion and I know it's pretty straighforward. The MPi is a whole different thing as Guru says.
Fishy has added a bit more info following a phone call but I would still like to hear from someone who has actually done this swap.

[UHR850]

Hi Nick, I got the same question from Stephen from the USA. Is this the same man ?

Good Morning Kees...
I can't remember if I told you about the latest DOWNTON project. I have been having problems with the Multi Port Injection unit so I have decided to remove the MPI fueling system and replace it with twin 1.5" SU carbs. I have to replace the existing fuel tank with an eariler model tank without a submerged fuel pump. I have to replace the ROVER ECU and replace it with a programable ECU so that I can only use the ignition timing portion of the ECU. Run new fuel lines and replace the high pressure fuel pump with a standard carb. fuel pump.

Do me a favor here will you...
Will you ask around your Mini community and see if anyone has removed the MPI system on a late model Rover Mini and replaced it with twin SU carbs. My DOWNTON is a 2000 Rover Model 5.5 Mini.
Thanks for the help Kees.

[nick rogers]

Hi Kees, Yes it's Steve who's asking.
Nick

[UHR850]

Well, hope some one knows something !!