"kangarooing" 2.1DJ

[eric]

Happy New Year to you Matt and I hope you will solve your prob out soon.

Sadly, I cannot help with advice and/or guidance as even "RON 98" has perplexed me!

I too had the exact same problems as you when my LPG system developed a fault and had to run on petrol for a time. If I run out of LPG now, I just put up with the pi££-poor running on petrol for a while, until I can get replenished with gas, when it runs as smooth as a baby's bum.

However, I am minded to print off this whole thread and pass it to my local "Tuning Guru" for his advice. ( Back a year or so ago, he identified my problem of kangarooing, misfiring and cutting-out which baffled the RAC, down to a fault in the ECU. Subsequently, got a `new` one from CJ). Problem solved.

I shall let you know the outcome of his deliberations in due course, ok.

Eric.

[eric]

Oooow, I've just had a brainwave Matt!

Have you got a `System Restore` button on your bus? Just a thought.

Eric.

[mattk918]

No system restore i'm afraid, though that'd be good.... or a CTRL+ALT+DEL key combination!!

[mattk918]

So "new"trial ISCU arrived today (thanks Aiden) and I am now confused (even more!)

With the Stabilisation valve disconnected it was idling at ~900rpm. Connected the valve and it revved up to 3000rpm. Slowly dropped to a bit over 2000rpm then started revving up and down, building up to about 2500rpm holding for about 4 seconds, then dropping to 1000rpm and repeating ad-infinitum! Is this normal "learning" for the ECU with a new ISCU or does it just mean that the ISCU or stabilisation valve isn't working (didn't happen with either of the 2 I've already got ????

[tencentlife]

I haven't read the whole thread, but have you done a thorough cleaning on that idle speed valve? Take it off, douche liberally with carb cleaner and blow out with compressed air, do it twice, at least. The valves catch oil residue due to the crankcase ventilation being ported next to their air inlet, so they gum up. The valve has to move very freely since the controller opens/shuts it very rapidly (the humming you can feel). You can bench test the valve by just putting 12V to it, no polarity. It should snap very smartly open and shut. If it makes a dull sound when testing it is dirty inside so clean it some more.

Also, I know you know the TB switch has to be closed to turn on the idle speed controller as well as put the ECU into idle mode. To be sure the TB switch is closed you really need to test it with the engine idling. The TB's are so shoddily built that they wear in the extreme, so there is often so much play in the butterfly shaft that engine vacuum pulling on the butterfly moves the shaft enough to open the switch. Temperature changes also aggravate this. Always check that again with engine warmed up and idling.

Good luck.

[mattk918]

In this post ..... viewtopic.php?f=2&t=47024&p=7327577&hil ... e#p7327577 it says the following.

5. Now meaure the voltage between pin 5 and pin 8. You should see 5V......If you do see 5V then your ISCU is more than likey fecked.......so try swapping in a replacement.

........HOWEVER - if you don't see 5V it means that your throttle body switch is not closing at Idle....this is what threw me. I tested the Throttle body switch with the motor not running - moving back and forth by hand, and by using the accelerator cable. However for come reason as soon as the engine was actually running, this was enough to not close the switch at Idle!!!!!! The good folks on the Samba have suggested that it was the buttefly valve inside the throttle body that was sticking....that and/or the accelerator cable was just a little too tight.

However I see 0V between pins 5 and 8 at idle and 5V on open throttle? It is switching OK between idle, open and full and I would have thought this was correct, but this post implies the opposite. Anyone able to confirm either way?

Anyone got any ideas on this element of it all. It just seems like my TPS is switching correctly on full and closed throttle, but giving 5V when it should be 0V and vice versa???? Tests on the TPS in isolation all seem OK cold and warm, but the signal at the ISCU is opposite???? Maybe I have just lost it completely and am now talking total rubbish..... will have to get the meter back out again on Sat unless it is still as c-c-c-c-cold !!!

I've cleaned the valve a couple of times and the garage also did it, but I'll empty another can of carb cleaner though it at the same time............

[tencentlife]

When you test V at pin 8 for the ISCU you are reading the 5V output the ECU puts on that line (this is common with one of the pins at the TB switch). When the TB switch closes, it grounds that 5V signal, to a ground bus inside the ECU (ECU pin 6). Grounding the 5V signal takes it down to zero V, that's all. The signal to the ECU and ISCU is when that 5V goes to zero.

[mattk918]

so basically it is right as is ???

[mattk918]

Had to use it today, despite the poor running......couldn't get off the drive in anything else! Un-plugged the ISV and it stopped doing the crazy revving thing and I drove it like that, keeping the revs up by being in a lower gear.... not ideal for snow but.....

[tencentlife]

However I see 0V between pins 5 and 8 at idle and 5V on open throttle?

If this is what you're seeing at the ISCU conector then that is normal.

[mattk918]

Good good!

Just spent the last 1.5 hours out there taking off and rechecking/setting TPS, trying the different ISCU's, cleaning ISV again etc. Frozen now!

Might have found another factor since with alternate ISCU the revs were high and going up and down regularly. Cleaned the ISV again and it became stable at 2200rpm. Wiggled the wires to the ISCU and the revs dropped to 1000rpm. This obviously hasn't been noticeable previously if my ISCUs haven't been doing anything. Checked the crimped connectors in the ISCU socket, cleaned up the ISCU terminals and nipped up all the connectors, but they aren't great so i'll maybe remake them all at the weekend. Thing I'm not yet sure is whether the "loose situation" is when it is at 2200rpm or when it is at 1000rpm!!!!.

Does seem like there are a number of things wrong and it had just been played with and tweaked to compensate until it ran ok-ish

[tencentlife]

Sounds like you're getting closer. I got mine to work better too by spending some time on that ISCU connector.

Make sure you have a good clean connection at the coolant temp sensor, the ISCU reads it, too.

[mattk918]

No connection from ISCU to the Power steering switch wires. Discovered where they have been chopped and realised the PS pump has 2 spade connectors attached to the terminals without wires coming out of them!!!!! DOn't think it should make a difference, but it is yet another factor!

[syncrosimon]

Good work, sounds like you are a bit more positive now.

Simon.

[mattk918]

more positive, maybe
more persistant, definitely
more successful, definitely not



Looks like I may need to source another ISCU. Before that though I need to check whether the ISCU is actually getting the engine speed signal (continuity from ECU pin), 'tis getting the Temp II signal.

It's been runnign worse the colder the weather, so maybe Temp I isn't good as I previously thought, get my thermometer out again at the weekend.... reckon it might read 'kin cold!!!