Broken mpi

[Danny California]

Sat idling outside my mates house on thursday, the idle started going lumpy and sounded choked. Temp gauge was up so I turned her off and it wont run properly now.
So far I've:
Done a compression test (all good at around 13bar each)
Changed the plugs (No difference, but hey cheap as chips)
Checked for spark on each cylinder while cranking (all getting good spark)
Listened to the fuel pump and it's priming and running.
Cleaned the crank position sensor plug and the CTS plug
Got it on a diagnostic with the RAC, but he couldnt work out his computer so we never made a connection. Lame.

After this admittedly basic list, it will just about start (on a jump obviously since the battery is always flat) but it's a real chore and it sounds rough as hell. I managed to rev it up and keep it running but it was no where near driveable. It's as if the timing has thrown itself out the window, but obviously being mpi that's controlled by a couple different sensors and the ecu. So I've ordered a new CKP for tomorrow, and maybe that will help. I'm not hopeful though.

So can anyone help me out? ;D

[timsmini]

When was the last time you changed the fuel filter. Is your water pump running as high temp will make it run rough. Check the wiring to the lambda sensor.

[Danny California]

I've not replaced it before, could give that a go, would that really make it seem like the timing was out?
The car wont idle at all, barely starts, and hardly revs. Not sure what could have happened whilst just idling to cause that!?

[ljonez]

Check all the vacume hoses for leaks/splits

Also check the water temp sensor that plays havoc when it goes.

[Danny California]

How should I check these things? I mean I've done a visual check on the vacuum hoses and couldnt see any splits, and since I cant get the car to idle I cant spray anything to check for changes in engine noise.
As for the CTS I'll get one tomorrow since they're cheap, and try that.

[gar1380]

i had this problem with mine a few years ago and the throttle potentiometer was the fault

[Danny California]

I've got a spare TPS at home, so if I can't get it going I'll be trying that

[Danny California]

Replaced CTS and fuel pump. Still wont fire, and now the plugs are dry after cranking. I'm going to take the filter out again just for peace of mind that I didnt put it in backwards lol. I've avoided replacing the crank sensor as it's pretty expensive and I cant see it solving the problem (pessimist). I can take it back if I dont fit it, so I've intentionally left it til last.

Any more ides?

[Danny California]

Replaced the crank sensor now, and it starts. But it's not running well atall, on 2 or 3 cylinders and wont rev past 4k. I'd guess cam position sensor now, since it's like it's not running in sequential fueling mode, which means the rev limit is lowered. Gonna give that a clean and see what's what.

Here's a vid of it running for you all to have a listen, ignore the rattle, thats the exhaust!

youtu.be/YGD_GG4KKUU

[Danny California]

Ran it now with various plug leads off, and it's definitely not firing on all four. Cleaned and replaced the cam sensor, but interestingly I forgot to reconnect the sensor when I went to try it, and it fired up and ran the same as after I realised and reconnected it. Weird.

[coedy]

Do mpis have a limp home mode built into the ecu?
If it ran the same without the ecu getting a timing signal as without it then maybe the ecu isn't getting power or naff earth?
(just thinking from a megajolt perspective)

[Danny California]

I know if the cam sensor goes down with the engine running it goes into a lowered rev limit mode with non sequential fuelling, and I'm tempted to blame that since it didn't make any difference when it was unplugged. I've cleaned up the ecu earth now like you said but it's too late to start it now. Rac couldn't get the diagnostics to work which is pretty annoying, would have told me if the cam sensor was down. I've got a fanny mold full of sensors back home, so I'll try them after Xmas. What gets me is how it happened randomly while just idling. That's why I now reckon its cam sensor. Think it's the same as the crank sensor on the k series so I might take a trip down the scrappies at some point.

[ljonez]

The problem is the mpi isn't to the obd2 standard so pretty much most diagnostics machines won't connect to the ecu.

Nine broke down before , I cleaned up the coil pack bracket and it worked (possible the coil pack earths through the bracket

[Danny California]

Yeah it's still obd1 right? If I could only get it to run I'd take it to a rover specialist and they'll be able to see/clear any faults.

Oh right, so you took the coil pack off and cleaned up the bracket? Does anyone know a way of testing the cam sensor? I"ll test the T/P tomorrow as I forgot today, but I reckon I'll be abandoning over xmas tbh

edit: Oh I should add that I checked to make sure there was fuel getting through, and yes there's plenty. More than enough for smooth running

[dogsbreath]

Hey danny if you get stuck and want to get it to a rover specalist and your still in bris i can tow it for you i,ll be back home tomo and have a few minis to tow then as well if that helps.

rob

[ljonez]

Yep only where it touches the block to provide an earth.

I don't think it's even obd1 it's rovers own

[Danny California]

I'll go clean up all me earths now, see if that makes a difference.
I may have to take you up on that offer after christmas if it's still open! I've got exams early january so I really have to stop messing with the car now.