92 replies to this topic

[Major Burkenshaw]

Could you not rule out the alarm by taking the fuse out?

I think you have reached the point where you should basically start again with your fault finding. Making sure you follow exactly what Sprocket and others have surgested.

[mogg]

I have read through this thread several times now and would like to ask if you could please clarify what all you have done, and what all you know about the problem. At this point I am chasing rabbits trying to keep track of the repair history, and consistency of the symptom, and am throughly confused.
For instance, one of the quotes read like this "My mechanic informs that the Air Temp sensor and MAP sensor appear to be functioning normally". Earlier you mentioned that he did not have any experience with efi minis. So I wonder, how did he test it? Was the part replaced? there are some other recommendations that I was unsure if you had looked into or not.
My interest comes from having a slightly similar issue that remains unresolved at this point. I also live in an area where help is quite limited, and by no means am I a mechanic.
Also, you mentioned you had the car for three days before this took place.. So was the previous owner driving the car, or was it sitting around most of the time? the history predating your acquisition interests me somewhat also. I think that the alarm maybe a bit of a red herring, just disconnect it if you are still not convinced. You have had the car long enough to evaluate the issue more carefully so I am wondering if you original symptom has altered any from your previous description..
thanks and best of fixing

-r

[BoyracerAU]

Mogg, sorry. I realise this thread has been going on forever and is a bit all over the shop. I realise my lack of knowledge and experience in all things mechanical is probably also making it hard to describe the problem clearly.

In as concise a fashion as I can, here is the chronology:

21/12 Purchased car. It was a daily driver. The car was about 60kms away from my place. I had a magic drive home including some freeway driving at speeds of up to 120km/h. The car didn't miss a beat for three days.

24/12 Had a car alarm/immobiliser installed in the morning. I also came home and changed the speakers for some new Sonys I'd bought the day before. I did two short trips in the afternoon, then undertook a third trip when the problem appeared for the first time.

The problem:
The car always starts and idles perfectly when the engine is cold and also when it is at operating temperature. It'll also rev very freely and has lots of get up and go when the car is cold.

However, once I reach operating temperature it very intermittently won't allow me to rev past about 2,000rpm. I can never say when it'll happen. But when it does happen, the car feels like it's been punched in the chest. It's totally winded. If you try to rev up past 2,000rpm, you can hear a clicking noise that sounds like a relay and the tacho needle flips up and down. It basically gets slammed down hard back to idle speed. When it does this, it'll still idle evenly and start, no worries. It just won't rev out.

On the afternoon of the alarm installation (the first time the problem appeared), I discovered the red vacuum line had come off the back of the inlet manifold. The little elbow was quite brittle and there were cracks all through it. I guessed the alarm installer had bumped it as I did see him feel his way around up there when he was looking for a place to put the siren. Anyway, judging by the condition of the elbow, it wouldn't have lasted much longer in any case. I popped it back on, but the problem was still there.

Since then, I have:

Changed the vacuum lines & elbows, fuel filter, oil, oil filter, coolant, air filter, spark plugs, coil, HT leads, dizzy cap, rotor button, tyres, gearbox rod selector boot & steering rack boots.

There are two professional mechanics involved.

One is 1,200kms away. His involvement only went as far as receiving my ECU, reading it, resetting it and sending it back to me. He reported that the IAT sensor was faulty.

The other is not familiar with EFI Minis, but he is a Mini enthusiast. Without the right diagnostic gear, it's been very hard to figure out what's going on.

Sprocket kindly brought an Ebay auction of a Crypton ACT1 to my notice. I succeeded in winning the auction and I received it this week.

After finally susing out how to use it, I tested the car three times in succession and the result was NO FAULTS FOUND.

This has lead me to conclude that the sensors are all fine and that something else is to blame.

This afternoon, I had a look at the alarm. Of the 22 wires which go into the alarm module, I pulled the inline fuse from the Constant 12v line but found that I couldn't start the car at all with this out. I also fund that the wires which go from the alarm to the shock sensor had come off so I reconnected them.

In the engine bay, I also found some dodgy wiring.

Looking in from the front of the engine bay, immediately to the left of the relay pack is a socket into which a four wire plug is connected. I'm guessing it's also a relay as it doesn't go anywhere. I'm not sure what it's connected to. The main power wire (brown) was connected to a glass fuse. The fuse in turn, connects to a Purple/Yellow wire which goes into the aforementioned socket/relay. Whoever introduced this fuse to the system had merely twisted the wires together and bound it with electrical tape. They'd done this both before and after the fuse.

I took the car for a drive this afternoon and it went very well for quite awhile, but the problem did eventually appear again (say 10 minutes after the temp needle had reached operating temperature).

Curiously, this time there was one definite and severe buck (inlet manifold misfire). I pulled over (out of traffic), waited a few minutes, then revved it and found that the problem was no longer there. I drove the two minutes home without further incident and was able to rev freely and drive normally. I say this was curious because normally when the problem appears, that's it. It's there and you can't get rid of it. The only thing you can do is limp home and try to use the car without revving past 2,000rpm.

[Sprocket]

help me identify this relay. what are the other wire colours on the relay, is it definately a relay, is this relay yellow and has the name Siemens on the top?

Is this one of the late SPi with the 25 way blade type fuse box or the four way glass type fuse box, that also has several inline glass fuses under the scuttle panel?

Is the fuse for the alarm independat to the rest of the wiring, IE was it specificaly installed for the alarm and the alarm on its own? if this is the case and when you pulled it and you were unable to start the car, the alarm is still functioning as an imobiliser.

Where exactly was the alarm wired into, what colour wires has the alarm been spliced into, where does the alarm take its power from. Colours of wires on the original harness please.

As said previously this is either the alarm itself causing the problem (hghly likely) or there is still a liquid lock happening in the vacuum lines or MAP sensor (likely) I myself have suffered the latter when I first drove the Mini after purchase and the symptoms were similar to yours.

One thing that is different is the Tacho 'bouncing'. This may be a problem with the main relay that supplies the ignition coil, injector, stepper motor and purge valve. Main relay is controlled by the ecu and should not alter state by any normal control of the ECU while driving. The relay pack itself could be at fault, or it could be that the alarm is spliced into the ignition coil circuit (likely) and it is the alarm that is causing the problem.

The 'bouncing' tacho is a tell tail sign that the power is being cut to the ignition coil.

It is a possability that needs to be examined. Again what said above is speculation. Idealy we need to know how this alarm has been spliced into the original wiring, wire for wire, colours please

If there are not many people that understand the Minis injection system then it is highly likely that your Auto electrician doesnt know either and there may be a slim possability that he has incorrectly wired the alarm without knowing it would cause adverse effects. It may be theoreticly wired correct but practicaly, it is not. Not having a go at your auto electrician I know the wiring inside out for the SPi as I had to work it out to replicate how it worked for the programable ECU, which was a whole other complexity, so armed with wire colours I can work out how the alarm could be affecting the injection system.

Sounds like we are getting close, just sorry its been this long and everything suggested has not effected a repair.

[mogg]

I don't know what a scuttle panel is either. I did not realize that the alarm was that involved. I must then withdraw the red herring comment. If the original wiring is a concern, we can work through that. Do you need a manual? If you don't I might be able to email you one, if your email will allow such a large file without dumping it as junk email. I would also like to know how the alarm was connected, and If that does not turn up any red flags, I hate to suggest it, but perhaps for now you might consider eliminating the alarm from the equation. You could always put in a kill switch or a detonator switch like max did in Thunderdome.

Oh yeah, one other thing I think you mentioned that you had done this but its an easy check. take a look at the wires connected to the coil. Give a slight tug on the terminals to make sure you have a solid connection, at just the right RPM that coil will shake around quite bad...but that would be too easy..
Take care

[Sprocket]

THe scuttle panel is the panel at the bottom of the windscreen. The inline fuses are only fitted to the looms with the four glass fuse box, NOT the 25 way blade fuse box. They are tucked under the scuttle panel around the wiper wheel box on the right hand side of the engine bay.

This is just an identification as to which loom you have as 1995 was the cross over year between the two. There are very few SPis with the 25way fuse box as production changed to MPi in 1997. That means there was roughly two years of production with that loom, and unfortunately there is no wiring diagram that I can find to match it. Some of the the Jap spec Mpis werent, and if I remember it was the Autos and AC variants that had SPi instead, that is the closest. That is available on the last Rover Rave tech CD, which there should be a link to somewhere.

[Avl_Paul]

This is just an identification as to which loom you have as 1995 was the cross over year between the two. There are very few SPis with the 25way fuse box as production changed to MPi in 1997. That means there was roughly two years of production with that loom, and unfortunately there is no wiring diagram that I can find to match it.

That's good info to have Sprocket as I have a '95 with that 24 way fuse block and the inline glass fuses you mentioned. I wondered why it only "sort of" seems to match the wiring diagrams in the Haynes manual. Not good to hear that we are SOL on a wiring diagram. That is enough info to scare me into thinking about carbs....

[BoyracerAU]

Hi guys,

I must say I don't feel like I'm on my own with you lot around to bounce ideas off. Even when you are all scattered across the four corners of the world. I'm sure Paul feels the same way.

Here's a pic with the 'relay?' circled in pink. It's probably unrelated to my problem, but at least it's one dodgy wire that has now been fixed.



I think my car is the same as Paul's. It has the 24 blade fuse box on the firewall above the relay pack.

I'm at work at the moment, but I will call the alarm fellow and see if he can isolate the alarm from the ignition circuit.

I'll let you know how I go.

[Sprocket]

Is that relay not for the air conditioning, and im assuming that is an after market AC kit??

[BoyracerAU]

I'm not sure if ti's after market or not.

This is the set up in the cabin. Is this an after market unit or factory?

[ICAM]

I'm not sure if ti's after market or not.

This is the set up in the cabin. Is this an after market unit or factory?

Seem like your SPI is a Japan CKD. It is the late SPI. Yeah the acond is a standard for the Japan Spec. Try look at the a/cond compressor, it should be UNICLAIR. A lot of these half cut available here in Malaysia.

Regarding the relay thing, I think you should visual check when the problem arise. Try touch the relay by hand (working condition should be slight warm)or you can direct by pass the relay. To be more precis , I will try measure my relay resistance and we can compare.

[BoyracerAU]

The airconditioning still managed to come on with the inline fuse taken out, so that fuse is not part of the airconditioning system. If I get an opportunity, I guess I really should try to find out what it is by following the blue/yellow wires to where ever they go. It doesn't hurt to know as much about the car as possible.


I'm about to speak with the alarm guy and offer him a deal. He's a bit irritated that he's already been called back once (about three weeks ago) to take the alarm out of the loop. I realise he sees this as me questioning his workmanship. He's a very touchy fellow.

Anyway, even though he's been back once already and claims to have isolated the immobiliser circuit, as far as I can tell he hasn't actually decommissioned anything. The alarm still goes berserk if you set it off and the immobiliser still immobilises until I press the button on the remote to switch it off.

So, I will get him back to decommission the alarm/immobiliser completely so I can test drive the car and then reinstate it - obviously properly, if it proves to be the fault.

The deal I plan to offer him is that I will pay for his time at his regular hourly rate, however if the alarm is found to be the culprit, then of course he will receive nothing. I reckon this is as fair as it gets.

Unfortunately, I can't think of a better way to rule out the alarm as being a likely suspect.

I'll report back with whatever I learn.

Edited by BoyracerAU, 04 February 2008 - 09:30 AM.

[BoyracerAU]

Well, the alarm/immobiliser is now ruled out as a possible culprit. The exercise cost me another 50 bucks and a lot of mollycoddling.

The alarm guy completely removed the alarm module from the car and reinstated the two immobilised circuits: namely, (1) fuel pump & (2) ignition crank. Upon installation, he had originally cut these wires and fed both ends into the alarm so the alarm can break the circuits thereby immobilising the engine.

I went to test drive the car and the problem reared it's ugly head as soon as I went to take off. I went a short distance before turning around and going back into the workshop. I was satisfied that the problem was still there even though the alarm wasn't. He has now reinstated the alarm.

I don't know if I've placed much emphasis on this before now, but the problem is more marked and more likely to appear when the engine is under load. It will happen when the car is just sitting there, but as I say it seems to be easier to make it happen when the engine is under load.

I guess there's nothing for it but to go right through the checklist again.

[Sprocket]

Bugger bugger ******** ********!!


Will the engine speed pick up if you gently accelarate? but the problem is severe when you quickly accelerate? If so it may be the throttle position sensor.

Go through cleaning out the MAP sensor again

Dont rule out broken wiring somewhere either, very strange, its frustratimg for me as well you know

[BoyracerAU]

I know Colin, you've been a great help. There's quite a few beers here in Sydney for you any time you're in town!

I feel a great responsibility to make a positive report very soon!


After all the reading I've done, I'm also inclined to think it's MAP related. I took the ECU out of the car and opened it up. I threaded a piece of wool up the pipe and put it in front of an electric heater for an hour. After this, the thread was still as clean as a whistle. Nothing on it.

The engine doesn't like to rev past 2k when it's like this. You can edge your way a little past it but it works out what you're doing and slams you back down to 850 quick smart.

Indeed, it has sometimes kicked in when the car was actually cruising along at 3,500rpm. All of a sudden the rev counter drops to 850rpm and you realise you're decelerating. The momentum of the car is not enough to keep the revs up...


I'm thinking of getting a second hand ECU/MAP and a Relay Pack. It's getting costly.