9 replies to this topic

[Willem]

Hello,

 

I'm a newbee but can't solve the problem with all topics in here.

I have a mini spi what won't idle.

Cold start is very difficult, but when it starts is runs only when I push the throttle a bit. til 1500-2000 RPM.

When the engine gets warmer I can relaese the throttle a little bit but when i relase the throttle it stops.

 

I have chacked vacuum and sensors, and all work fine.

 

When I read the ECU everthing seems normal.

 

Has somebody a clou what this can be?

 

Kind Regards

Willem (Netherlands)

 

I have txt logfiles from MEMS-Rosco but I don't know how to upload them.

 

MEMS-DIAG pictures:

 

https://ibb.co/swqB8gQ
https://ibb.co/jGcQrWy
https://ibb.co/vx0hFLf
https://ibb.co/JCrBwpG

 

 

[xrocketengineer]

Well, mine had two conditions when I bought it, when I fixed one the other one manifested itself. First the idle speed was too high. It turned out that the vacuum hose to the Thermac valve on the air intake was leaking. When that was fixed then the car would not idle properly or die and the the throttle response was poor (it was never good to begin with). The elbow on the second vacuum line on the back of the intake manifold going to the fuel trap had dissolved and it had gotten clogged up inside. A replacement elbow fixed that. A clogged up fuel trap can cause the same symptom. 

[genpop]

On the right lower corner you have the button "More Reply Options"

Then you get  "Search" and "Attach this file"

 

Then you may upload log-files.

[Willem]

Hello

Thanks for the advice. I checked vacuum lines but those are alright.
I attached the log files from MEMS-ROSCO by LeopoldG

Maybe someone knows whats wrong

Kind regards Willem


 2021-09-19_15.49.txt   17.91K   9 downloads  2021-09-19_15.20.txt   17.06K   5 downloads  2021-09-19_15.33.txt   113.11K   4 downloads

[xrocketengineer]

If the vacuum lines are not clogged up, then the next thing would be to check the fuel pressure. I had an S10 Chevy Pickup with a very similar fuel injection system (even the same fuel filter as the Mini) and it would barely idle and it had no power. After replacing many other parts with no success, I finally checked the fuel pressure and it was down to 0 PSI. I bought a new pump and replaced it and that solve the problem. However, the old pump was probably fine. There was a short hose that connected the pump to the metal pipes inside the fuel tank that had rotted. So, the fuel pumped by the pump would leak back out through the hose into the tank and no pressure would reach the injector.   

[genpop]

Check the fuel pressure  like xrocketengineer supposed.

But i think there is still a leak somewhere in thr vacuum system.Change the hoses and elbows to silicon ones.

rpm and map do not fit together.

Attached Files

•  rpm-map.JPG   60.68K   10 downloads

[Willem]

Hello

 

Thanks a lot. I will check both next weekend, I will reply the outcome.

 

Kind regards

 

Willem

[rolf]

Try this solution
1) take out the air filter

2) On the left below the air filter, there is a plug. Look if the connection pins are corroded. Very typical in the late minis. Sand paper the corrosion, put back the airfilter and check. 10 minutes work. If it works, buy a battery connections protective fluid to avoid corrosion of connections in the future.

And whatever the outcome of this solution, keep in mind that many problems in late models have to do with problematic plugs

[Willem]

We have changed the vacuumhoses, drain the fuel tank and a new fuel filter. The hoses were good and not affected anyhow.

Then we replaced the injector unit with an old one.

There after we looked at the membrane, after putting all together the motor idled but not very nice.

We think the diaphragm of the fuel regulator is not right anymore. Does someone have the partnumber of the membrane alone? I only can find complete injector unit.

 

@Rolf, what do you meen left below the air filter? Do you have an picture?

 

With kind regard

Edited by Willem, 23 December 2021 - 02:32 PM.

[Pops_Guild]

 

We think the diaphragm of the fuel regulator is not right anymore. Does someone have the partnumber of the membrane alone? I only can find complete injector unit.

 

Unfortunately the fuel regulator membrane or the surrounding associated parts were never sold as separate items. The were only ever sold as an entire throttle body setup and haven't been available to buy new since around Rover went pop. You couldn't even buy separate injectors when Rover was still around! The fuel regulator also doesn't take too kindly from being dismantled, so if you've taken it apart then in my experience (and I have a lot) they're tricky to get back together and working. Also in my experience it is really rare for the fuel pressure regulator to fail. It regulates to 1 bar.

 

If you think the fuel pressure regulator is at fault then you will need to take your chances with a second hand setup. I have spares of just the hydraulic body (which includes the fuel pressure regulator) and I also have the gaskets you will need when replacing it, just message me.

 

to be honest, your issue sound more like your an air/vacuum leak, your MAP reading is way off (should be 30-35 ish) and that is a sure fire sign of a leak. Can be any of the hoses attached to the throttle body or breather rail including the brake servo pipe off the inlet manifold. Can also be caused by exhaust manifold gasket. Also check the fuel trap is the not leaking itself and it's the right way round (green is clean).