Vts Conversion

[2052006 10]

Amazingly, I got my wiring right first time. After a bit a head scratching all I needed to do was reset the inertia switch and fuel pump primed, relay clicked and then it burst into it's very loud life

 

It is very loud and sounds ridiculous as I only have the manifold on, but have no suitable exhaust to put on at the moment. I don't think the neighbours are very impressed.

 

It is however, idling very high. It seems to start about 2k and then rise to nearly 3k (which doesn't help with the volume either). I have blocked up the servo vacum (as it's not connected to the servo yet) and this helped a bit, but it's still very high. There do not appear to be any other vacum leaks either.

 

Is it possible to lower the idle manually on these engines?

 

Could it be the fact that I haven't got a lambda plugged in?

 

Thanks

 

Pete

[2052006 10]

Re the high idle - I think it may be the ICV (idle control valve - think this is what it's called anyway) located to the rear of the throttle body/underneath the inlet manifold. The pipe off that seems to be sucking in a lot of air and it doesn't make any difference when connected to the air filter.

 

If I put my hand in front of the pipe to block some of the air, the idle speed goes down. Anyone know anything about these ICVs and what they are meant to do/how they operate?

[2052006 10]

Well, I tried using the stepper motor out of my XU10J2 which works in the 306, but made no difference on my vts engine. Now this may be because they are slightly different - they have very slightly different part nos on service box, but look identical. Then I tried the vts stepper motor on the 306 - did the same - idled far too high. Does anyone know if these two should be interchangeable?

 

However, I definitely need a new one, as in my ignorance I broke it whilst trying to "clean" it Still, at least it will rule it out with a new one.

 

 

Checked the continuity of the wiring between the stepper plug and the ecu plug - fine.

 

Does anyone know what causes these stepper motors to operate? Is it, for example, readings from the lambda or other sensors in the T/B?

[Miles 331 1 Cars]

No they can;t be swaped, But on allot of the 06 range they are a right pain in the backside, Remove it and clean it as they get dirty from all the oil etc from the engine, If that doesn;t work then I would get a new one, A S/H one could well do the same.

They work from the engine speed which is measured by the ECU from the CPS and if A/C fitted a sense from there to know it switch's on.

[2052006 10]

FFS! Fitted a new stepper motor and it's made sod all difference. Any other suggestions? Please

 

It still idles at about 4k+.

 

How much difference should unplugging the TPS and MAP sensors make? TPS - unplugged no difference at all.

MAP - idle goes down a bit for a second and then returns back up. When I unblock the stepper hose (which I'm doing to keep the idle down), it stalls. Whereas when the MAP is connected, revs shoot up. What does this mean?!

 

Thanks

[welshpug 1,627]

did you re-set the ecu when you fitted the new idle valve?

[2052006 10]

YES - ecu reset - at least I think so.

 

Should it make any difference to the running of the car (at idle and with revs) when I unplug the TPS? It makes no difference whatsoever with mine - is this the problem??

[Anthony 1,000]

Should it make any difference to the running of the car (at idle and with revs) when I unplug the TPS? It makes no difference whatsoever with mine - is this the problem??

Probably not - on a friends GTi-6 I unplugged the TPS whilst fault finding and it had no effect on idle at all, and indeed he drove the car home just fine without the TPS plugged in. I'm hazarding a guess that the ECU probably only really uses the TPS for overrun fuel cut and for acceleration/WOT enrichment, as it's got the MAP sensor for engine load.

 

With the pipe to the ICV blocked off completely, does the idle speed drop to below 1000rpm?

 

If you get stuck Pete, I've got spares of some GTi-6 sensors and a spare inlet manifold/TB that you're welcome to borrow to help diagnose the fault.

[Sandy 189]

Is the purge canister connection onto the inlet blocked?

[2052006 10]

Yes, purge cannister connection blocked off (and I've tried it with the purge valve connected just to be sure!).

 

Anthony - So TPS not an issue. This ties in with other stuff I've read.

 

With the ICV pipe completely blocked, it will stall. Think this suggests that there can't be any other vacuum leaks? Which I'm pretty sure there aren't.

 

I'm convinced the probelm lies with the operation of the ICV. I've tried 3 now (one being brand new, bought today in a fit of haste). It can't be the actual ICV therefore, more whatever is (should be) controlling it. I just don't think the ICV is moving at all. I've checked continuity between ICV plug and ecu and all seems ok, so it's not a breakdown in the wiring.

 

One thing I have found is that unplugging the green coolant temp sensor (for ecu) on the stat, - no difference to the running of the engine. Should there be?

[Miles 331 1 Cars]

Check the Stepper motor wire's from resistance from there to the ECU, there might be a broken wire, Long shot but worth looking at

[2052006 10]

I've checked the continuity, is this what you mean? 4 contacts on the ICV plug match up to 4 on the ecu plug.

[gti-si 0]

I've checked the continuity, is this what you mean? 4 contacts on the ICV plug match up to 4 on the ecu plug.

 

Don't be fooled, I had this problem. There may be a connection between both ends, but have a read of my thread here, there may be huge resistance at some point along the wires. I'd check the wires and see if your seeing 12v's. There's a diagram showing which pins should have what voltage for the ICV.

 

HTH

 

http://forum.205gtidrivers.com/index.php?s...c=92288&hl=

Edited June 28, 2009 by gti-si

[2052006 10]

Well, reading through your thread, it does sound like I'm having exactly the same problems with my ICV. I will have to investigate the wiring more thoroughly...

 

Thanks for the help though.

[2052006 10]

Right - it appears the problem may be that I'm only getting 5v at the ICV plug rather than 12v. Could someone do me a favour and check this on their gti6 engine?

 

Anthony came round and had a good look at what was going on (cheers!) - but we are a bit stumped as to why it's only getting 5v (for example, we've swapped the ecu, double relay and checked the ecu to ivc wires direct from battery which carries 12v successfully). Need to confirm what voltage we should be getting first though - please

[gti-si 0]

As per the thread I linked you too

 

 

I had to buy a new loom btw. Never found the problem, but I think it was the ECU plug, or a break in the wire somewhere, but I certainly couldn't find it

Edited June 28, 2009 by gti-si

[Anthony 1,000]

As per above, I've just been over having a look at this for Pete.

 

The fault appears to be that the ICV simply doesn't move at all, and remains in whatever position it is in when it is bolted to the car. Resetting the ECU or swapping ICV makes no difference. Blocking the pipe leading to the ICV and thus starving it of air drops the revs down low enough to stall the engine.

 

Checking the four ICV pins shows pin 1 and 3 getting 5v with ignition on, and pins 2 and 4 getting 0v. This is strange, as both Autodata and gti-si imply that it should be 12v rather than 5v, and assuming that's the case that's likely the cause of the non-reponding ICV. The four wires between the ICV and the ECU plug have been checked, both for resistance (all showing approx 0.4 ohms) and voltage drop (all four show 12.3v a wire from the battery positive is connected to the other end with the ECU disconnected, suggesting that there's little voltage drop at all). Checked the coolant temp sensor, and that's showing approximately 1800 ohms, consistant with the known-good 8v coolant temp sensor that I checked.

 

Tried swapping over a known good ECU, double-relay, MAP sensor, and ICV that I've got - none of which made any difference, and left us scratching our heads.

 

Can someone with a working GTi-6 engine and a multimeter possibly double check what voltages they are getting at their ICV? Simply unplug the connector from the ICV, switch the ignition on, and confirm whether you're seeing 5v or 12v at the ICV - I believe that it should be 12v at pins 1 and 3, as per the picture above.

 

Assuming it should be 12v, I'm a bit stumped as - in theory atleast - with both the ICV, ECU and relay swapped for known-good items and the wiring between the ECU and ICV checked, there's no clear reason why it won't work!

[2052006 10]

Ok, so it should definitely be 12v.

 

Question is why it's not 12v then:

 

We've fed 12v direct from battery through ecu plug to icv plug - so it's not that part of the wiring or those plugs.

 

We've changed the ecu - no change

 

We've changed the double relay - no change

 

I don't like the sound of having to but a new loom

 

Edit: beaten to it with a rather more comprehensive explanation of what we did!

Edited June 28, 2009 by 2052006

[gti-si 0]

Ant, it's definitely 12v. I tried with the new loom, when I found the ICV working. I put a multimeter on it and pins 1 and 3 definitely were recieving 12v from the ECU at the ICV plug.

 

Very very strange

 

P.S

 

I still think someone should check if they can

Edited June 28, 2009 by gti-si

[2052006 10]

Well, after spending the whole weekend thinking it was French wiring at fault, it turns out mine's worse

 

Turns out, I was missing a switched live. I knew I had wired up my reverse light somewhat incorrectly, so fixed that. After lots of headscratching (my brain is a mush now) I figured I was missing a switched live. Wired it in, saw 12v at the icv plug, fired it up, and idled as it should. I was rather chuffed with myself.

 

So chuffed in fact, 10mins later I went and sheared the f-ing bleed screw on top of the stat housing. Aaaargh!!

 

So if anyone has a thermostat housing (no need for actual stat or sensors) that they would like to sell me - PM me. Cheers.

[welshpug 1,627]

Well, after spending the whole weekend thinking it was French wiring at fault, it turns out mine's worse

 

Turns out, I was missing a switched live. I knew I had wired up my reverse light somewhat incorrectly, so fixed that. After lots of headscratching (my brain is a mush now) I figured I was missing a switched live. Wired it in, saw 12v at the icv plug, fired it up, and idled as it should. I was rather chuffed with myself.

 

So chuffed in fact, 10mins later I went and sheared the f-ing bleed screw on top of the stat housing. Aaaargh!!

 

So if anyone has a thermostat housing (no need for actual stat or sensors) that they would like to sell me - PM me. Cheers.

 

wind the remains out and fit a new screw, easy

[2052006 10]

It's not come out very well, so the threads are a bit buggered. Think it'd be easier and safer just to fit a new one and be done with it.

[welshpug 1,627]

have you tried a tap through it to clean the remains out? brass is softer than the alloy housing, you can just stick a coilpack cover bolt in the hole for the time being.

[2052006 10]

Not tried a tap - but you're right the brass is very soft (also, the coil pack bolt seems spot on - I knew I had seen one similar to the bleed screw but couldn't remember where!) Would a local motor factor sell the right taps?