7 replies to this topic

[hsamy]

Hi everyone, i am new to this forum and have a problem with my 1999 Rover Mini MPI. The car is in Dubai and it came from Germany so i purchased it about a year ago and have been having many issues with it since then. The most recent one is misfiring in cylinders 2 and 4 according to my mechanic. We changed almost everything; spark plugs, wires, coil, the entire throttle body assembly, and have come to the conclusion that the ECU is faulty. I am told that the injectors are not spraying fuel consistently. Can someone please advise what to look for given this description of the issue? Thanks 

[sonscar]

Vacuum pipes,fuel trap,fuel filter spring to mind.cyls 1&2 use the same injector as do 3&4.cam sensor faulty?just thoughts
You have checked engine health,compression,valve clearance manifold leaks,Steve..

[68+86auto]

Get a mechanic with an oscilloscope to have a look. It can then easily be determined if it is an injector issue vs ignition issue and what is the cause.

Edited by 68+86auto, 20 May 2025 - 10:27 AM.

[Ethel]

I wondered if it had been plugged into a scope & they didn't realise the MPI has asymmetric injection for the siamese ports.

 

It does seem unlikely to be the ecu if it's firing at all.

[Fast Ivan]

Have they established if there is or isn't sparks coming from each of the leads? Have they done a compression test and do they have the results? 

If they're content to just swap things out then there's the crank and cam sensors left to go

[alpder]

I had an '80s Ford EFi give trouble recently - stuttering on acceleration, low on power at top end. I figured injectors and changed them for recon. Didn't help. So changed *everything* else, one by one. Having finally ruled out absolutely every other possible cause, I finally trusted my original instincts and bought a set of NOS injectors: problem solved. The "recon" injectors went back. With a strongly-worded note. I now have a shed full of Ford EFi spares.

 

You haven't mentioned swapping-out injectors. Being mechanical parts they tend to fade-out slowly, rather than die suddenly and completely. So for a "still running but badly" situation, they're surely high on the list of possible causes once ignition is ruled out. Of course, could be something dead simple: clogged fuel filter or fuel line, say.

Edited by alpder, 20 May 2025 - 03:24 PM.

[bpirie1000]

Have been some very questionable leads going about lately....

Maybe change to old ones or switch the leads se if fault follows..

[mab01uk]

See link below for diagnostics tracing and fixing common faults on the MEMS 2J (Modular Engine Management System) fitted to all MPi (Multi-Point Injection) Minis.

 

Mini MPi Diagnostics - Car Mechanics Magazine (June 1999) :-

https://www.theminif...anics-magazine/

Edited by mab01uk, 20 May 2025 - 10:37 PM.