82 replies to this topic

[genpop]

This is from Rover electric library: Possibly the relais for the purge valve inside the main relay is sticking!

Attached Files

•  carboncanister.JPG   94.44K   2 downloads

Edited by genpop, 06 February 2020 - 04:50 PM.

[Robbie693]

Hmm makes sense, if it is dumping fuel vapour all the time that would explain why the IACV is bottomed out trying to control the fast idle caused by the excess fuel. Correct?

 

I managed to open the log files in Numbers (Mac equivalent of excel) and I can see that the charcoal canister readings are mostly zeros (open?). There are a few instances of other numbers - 16, a few 4 - but I don't really understand what this means - I thought it would be just open or closed?

[genpop]

Zero is closed.You are right, i thaugt the same, zero and one.But you may easily check by disconnecting the electric plug.I will have a look to some other logs but here is the graph of your log iopened with mems analyser from rmrsoft.

The second one is from an other car where it works right.The red beam is at the position where water temp reached 80 degrees.

Attached Files

•  purgevalve.JPG   72.29K   2 downloads
•  purge demo.JPG   81.83K   3 downloads

Edited by genpop, 07 February 2020 - 01:40 PM.

[Robbie693]

Went to try the PCV today, ran the engine up to temp then disconnected  the power to it - no change. Clamped the hose no change.

 

Switched off and disconnected the hose from the PCV to the breather rail, restarted and the revs jumped up to over 2000rpm. Put my thumb over the end of the hose and the revs dropped back to the usual 1400 or so, so it looks like the PCV isn't the cause.

 

I didn't have any brake cleaner or Easy Start so I tried spraying WD-40 around the manifold but this didn't cause anything (not sure if WD40 would anyway to be honest).

 

I did a log during all this - the switch off and restart without the hose on can be seen towards the end

 

 PCV.txt   378.29K   3 downloads

 

 

[genpop]

WD-40 is oil, has no effect on rpm of engine.

I´m sorry.

Does nobody else has some ideas?

[Robbie693]

No worries - I really appreciate all the help you have given me on this, even though we haven't found a solution I have learnt a lot on the way 

 

I'll keep posting my findings incase anyone recognises something wrong.

 

After the tests with the PCV, next time we came to use the car the idle had gone mad - revving constantly at 2000rpm and never dropping.  I discovered the plug to the TPS had come off - reconnecting it restored the idle to what it was before.

 

Yesterday I tried fitting a new, spare, TPS just to see what would happen but it didn't seem to make any difference. I did a log and it looks like the TPS voltage has dropped to 0.3 with the new one fitted, can't think why. Anyway I re-fitted the old one so I have the new one as a spare for the future. 

 

I bought some carb cleaner and sprayed that around all the breather hoses, didn't seem to make the idle rise anywhere, If anything the idle dropped slightly when I sprayed some at the throttle body base and the inlet manifold, possibly because it is cold and the weather was freezing cold too...

 

I tried refitting the old distributor cap and rotor arm incase I had a bad one but this failed to make a difference.

 

So today I started the car thinking that it would be the same as the last run yesterday but the revs had shot up to over 2000rpm with a cold engine, as if the TPS plug had come off. I switched off and removed the air cleaner, checked the plug but it was still connected. I restarted and the revs were still high so I wiggled the plug and nothing happened but when I unclipped it and slid it off the revs dropped while it was half off and then rose again when it was fully off... How being half connected and fully connected can be different I have no idea but I managed to re connect and get it to idle back as it was before again somehow.

 

None of this makes any difference to the way the revs hang when releasing the throttle though, or the way the the revs hunt up and down though. 

 

Log file with the new TPS attached-

 

 2020-02-11_13.21.txt   117.82K   4 downloads

 

 

[genpop]

"when I unclipped it and slid it off the revs dropped while it was half off and then rose again when it was fully off."

 

Have a look to the contact area of the plugs.

Bent them that there is more tension and put some acid free grease on them.You have to take them out of the plastic plug housing.

 

Could you do a logfile while driving?

Edited by genpop, 12 February 2020 - 08:51 PM.

[genpop]

Before doing anything, could you do a logfile with only ignition on and then stepping on the accelerator a few times, slowly and then quick.

Edited by genpop, 13 February 2020 - 09:11 AM.

[Robbie693]

Thanks, haven't had time to check and tweak the plug pins yet, should be able to do the logfile for accelerator on/off tomorrow morning though.

[Robbie693]

I did the accelerator pumping log - attached.

 

I'm afraid the car is now in the hands of a Mini specialist, I have run out of time to play with it for the moment 

 

They did say that it looks like I have already checked most things! Lets see how they get on...

 

 2020-02-14_10.09.txt   12.42K   5 downloads

[genpop]

Hi Robbie,

there are some values i can not interpret, i fear your ecu has a fault.Attached your values in an excel sheet.In the yellow rows throttle potentiometer do not match to the throttle angle.Does this car have an idle switch? From the construction year it shouldn't have one.

I am eager what the fault was.

Attached Files

•  throttle vers angle.JPG   47.21K   11 downloads

Edited by genpop, 17 February 2020 - 01:08 PM.

[Robbie693]

That's very odd - could that be caused by the TPS plug? (I didn't get time to check the pins for loose connection)

 

Hope it's not the ECU - ATP were supposed to fix everything that was faulty

[Robbie693]

Fixed!

 

Car is now idling at 850 rpm, actually lower than it has done for a long time. It's a bit disconcerting at first - not being used to it I keep thinking it's going to stall but it's fine.

 

Took it to Southam Mini's who did a great job, despite being an hours drive away they were the only people I could find who I would trust to do both the SPi specific diagnostics and troubleshoot the mechanical side, rather than just any old tuning place. Even Ex Rover dealers weren't confident working on it...

 

So they found two main things - the sandwich/spacer plate between the throttle body and the manifold had warped slightly causing an air leak (they noticed the air readings weren't quite correct) and also I had set the valve clearances too loose (!) They also tweaked the TPS plug pins for me as I mentioned the concern and tightened the fan belt which was slipping without squealing - I had noticed a burning rubber smell and rubber deposits on the pulley.

 

For the tappets, I set them as per the Haynes manual for a 12A engine which is 0.33 to 0.38 mm. At the time I noticed some were tighter than this so I loosened them off so that they were all 0.35 mm. Colin at Southams told me he sets them to 0.012" which the same spec as the older engines (0.30 mm). This apparently had a big effect on bringing the RPM down. 

 

Thank you very much to all who have helped out with this, particularly Genpop who has been particularly attentive in providing troubleshooting tips - I learnt a lot along the way and know a bit more about the Mini. It just goes to highlight the difficulty of diagnosing from a distance - just because I say I have checked something doesn't mean I necessarily checked it correctly!     

 

So what valve clearance settings does everyone else use? Is the Haynes info incorrect?

[genpop]

Thank you for the flowers!

A new log-file would be great.

[Robbie693]

Here's the new log.

 

It was running a little faster today - 950 - 1000rpm, brought down by some lively driving for a bit so may be because it was crawling in heavy traffic last night for a long time (battery was slightly sluggish to start too).

 

According to the memscan the stepper is still bottoming out but I know that the garage set the stepper up with an ACR diagnostic scanner so perhaps this is a flaw with the software...

 

Either way it's running very smoothly now, revs fluctuate a small amount but I'll worry about that if it becomes a problem for passing the emissions test. It does need an oil change anyway so that may help.

 

 2020-02-21_09.56.txt   87.65K   11 downloads