A few more teething issues....

[Fizzy]

Hi Guys,

Just spent some time putting on my new ISCV, thats been pocvip'd by Paul - Thanks again! :thumbsup:

A bit fiddley trying to get it back in with engine in situ, but I managed it.

Started up - and while it was warming up, it was at 1000 rpm. Sorted!!! However once it warmed up it went up to 1800 rpm and stayed there? :confused: Took it for a spin in case it needed to be driven a bit to settle - no effect. Letting the car cool down to see if I can recreate the problem. Perhaps I need to ground that aircon wire or something?

Also noticed that what I think looks like some sort of coolant channel through the ISCV housing isn't connected. Theres a pipe which sits underneath the throttle body housing which is the inlet from what I can see (does it cool throttle housing too?) - could this be a possible cause?

Also noticed when I checked the oil cap, there was a lot of oil sitting in the oil channel (and my car is on a slope with rear pointing downwards :O ). When the engine was running, I took the oil cap off and the engine revs dropped a lot - and as soon as I put it back on it climbed again. I think I may have a problem with one (or more) of my ignition leads - would a misfire cause this sort of behaviour? I was getting a lot of smoke from the exhaust, but assumed it was down to all the water and melted snow around. :P

Hmm... may need to invest in getting the engine running sweetly before I get an SC unit... :confused:

[Enthalpy]

Engines get surprising boosts in fuel economy and emissions if you can heat the air at low port velocities (idle). This helps atomization. That's what the loop is for. It heats the air, but only at idle.

[nik]

learn something new everyday..:thumbsup:

[superchargedsam]

its good to learn something new every day and rekon we just did with that info !

[foxy-stoat]

when i fitted my ISCV it usede to randomly idle at 2000 rpms, until you switch off and start up again.

now its been on a few weeks, its idling normally and never stalled since.

so i reacon give it time and it will sort it out, maybe reset the ecu too..?

[Fizzy]

when i fitted my ISCV it usede to randomly idle at 2000 rpms, until you switch off and start up again.

now its been on a few weeks, its idling normally and never stalled since.

so i reacon give it time and it will sort it out, maybe reset the ecu too..?

Hmm... ok, I tried stopping/restarting the car a few times once warmed up, and it still idled high. I'll try resetting the ecu - which fuse is that again? Probably just disconnect the battery for a bit as I want to install some other gear anyway. ;)

[superchargedsam]

defo give the ECU reset a go for sure as that shooul help somewhat !

[biteme]

Just leave it off for over ten mins mate!

[Fizzy]

Hmmm.... well, took off the iscv, and checked it over. Looks ok. Smoothed off the pocvic mod a bit in case it was catching or something. Refitted the iscv, using a bit of gasket sealent on the gasket just in case. Then disconnected the battery for 30 mins.

Started the car, and its idleing at 1100 rpm or so when warming up. Took it for a spin, and when it was warmed up it idles at 1900 rpm again. Does this no matter how many times I stop and restarted the engine. :(

I'm going to put the original one back on (as thankfully I bought a second supposedly "new" one off ebay that was pocvip'd) and see if the problem remains.

All very annoying. Would leave it for a while to see if it settles down, but when I took it for a spin the other day for some shopping, I was sitting at some traffic lights with the engine idleing, and there was a lot of smoke from exhaust... <:(

So, I think I'll put it back as it was, and if that sorts it I'll get an aftermarket ecu to sort out the idleing issues. :thumbsup:

[GaryA]

How about with the original one disconnecting it when your engine is ideling where you want it to then sending it paul to POCVIC in that position ? Or am i being :imslow:

[Paul Woods]

only just reading this,fizzy the 3vz-fe ecu holds the ISCV open further to increase the idle to around 1800rpm when its engaging safe mode....i know this because my mk2 v6 was doing it for a short while,the reason my car did it was because id hooked up the ignition lives to ecu onto permenant lives doh!!! and as the ecu was always switched on (even when ignition was off) it was waiting for both a cranking signal and an rpm signal,but it must only wait for these a set amount of time before it registers a code and engages safe mode.

Once id corrected my wiring doofus and reset the ecu it dropped back to 900rpm.So first port of call is to check for error codes...the pocvipped valve works perfectly,so it wont be that...there may also be auxilliary air getting past the throttle by some other means? did you open the throttle bump stop at all? try that...also check for any inlet manifold leaks,spray easy start around and see if the revs change,that would indicate a leak.

Personally i think its the ecu engaging safe mode for some reason,fairly easy to sort though.

Dont mess with the pocvip mod though,thats set to give you a guaranteed minimum 700rpm idle,the ecu should pull it back a little to give you around 900-1000rpm.

[Paul Woods]

wombat i pocvip them all in a set position that guarantees a minimum 700 rpm idle,provided of course people havent also altered the throttle bump stop.

So to recap,with no ecu connected to a pocvipped ISCV you should see no more than 700-900rpm,if you do then something else like an air leak or throttle being held open is causing the rise to 1800rpm.

To test this though you'd need to dismantle the ISCV,wind it down onto the parked position (on my weld) and fit it without connecting the multiplug.....start the engine like that and see what happens.

[Fizzy]

Well, I refitted the old one, and would you believe it - its idleing quite happily at 800-900 at the moment. It hadn't gone stone cold as yet so no idea if its going to idle low while warming up yet.

The only thing I have changed in each case is the iscv - nothing else. Checked for leaks/whistling noises, cabling, missing pipes etc but everything seems fine.

The car going to such a high revs in safe mode seems daft if its true. Could be a possibility though - although the likely candidate for causing such an issue is the new iscv as its the only thing that was being changed? All I did to the pocvip mod was smooth it out slightly with a very fine file (just so it was nice and shiney ;) ) so it shouldn't affect the position at all. It was idleing about 1100 when warming up on the new iscv, rather than the 800-900 as expected.

All rather baffling. How do you check the codes again - same way as the original mr2 engine? Anybody have a list of ecu codes for the 3vz handy?

I've not adjusted the throttle stop myself, and I don't believe Tony or Peebs did either.

Also - if your revs waver widley between 1-2.5k rpm, make sure you have the multiplug fitted onto the iscv. Thought my old iscv was knackered when I started the car up after first refitting it when it did this - only to realise I hadn't put the multiplug back on. lol

[Paul Woods]

thats very odd fizzy,very odd indeed....the pocviped valve should be working exactly like the old valve except its final resting place is held whereas your old valve isnt.....this leads me to believe your old valve is closing further and the engines getting aux air from somewhere else ie past the throttle.

Check the bump stop,check the cable isnt holding the throttle open slightly too...it cant be the pocvip valve as they simply dont allow more than 700rpms worth of air past when the ecu isnt connected.

So my advice is to refit the poc valve after winding it fully home onto its closed position and leave the plug off....start the engine and when warm you should see no more than 700-900rpm....if you do see more than that then the engines getting aux air from somewhere it shouldnt be.

Hope that helps mate.

[Paul Woods]

The car going to such a high revs in safe mode seems daft if its true

its not daft mate,thats what safe mode does at idle on the v6.

[Fizzy]

thats very odd fizzy,very odd indeed....the pocviped valve should be working exactly like the old valve except its final resting place is held whereas your old valve isnt.....this leads me to believe your old valve is closing further and the engines getting aux air from somewhere else ie past the throttle.

Hmm... possible. Although before I reset the ecu/tried fitting the new iscv, it did have a tendancy to idle at 500rpm, especially when warming up.


Check the bump stop,check the cable isnt holding the throttle open slightly too...it cant be the pocvip valve as they simply dont allow more than 700rpms worth of air past when the ecu isnt connected.

The cable is slack when the throttle is closed, so that seems fine. Doesn't look like the throttle stop has been changed at all.


So my advice is to refit the poc valve after winding it fully home onto its closed position and leave the plug off....start the engine and when warm you should see no more than 700-900rpm....if you do see more than that then the engines getting aux air from somewhere it shouldnt be.

Refitting it again... :hmm: I'm becoming an expert in fitting these now. :D Getting dark out now so I think I'll leave it until some other evening/weekend to ponder over.


Hope that helps mate.

It certainly gives me something to consider. The odd thing is it idles relatively ok while warming up - its just the high revs once its warmed up - which makes me think its more likely the safe mode issue.....?

[Paul Woods]

It certainly gives me something to consider. The odd thing is it idles relatively ok while warming up - its just the high revs once its warmed up - which makes me think its more likely the safe mode issue.....?

this is why i advise refitting the poc valve with it wound down to its bump stop and leaving the plug off.....doing this will tell you wether its the ecu holding the revs high or aux air getting past the throttle as i can 100% guarantee a pocvipped valve alone (with no ecu control) wont allow more than 700-900rpm worth of air past.

When i first came up with the mod i ran my demo car up to temp,waited until the engine was idling at 900rpm then pulled the ISCV plug off,this held the valve at its 900rpm position.So when the bump stop was added thats the minimum amount of air it will allow past,so either the ecu is allowing more bypass (by opening the ISCV further) or theres aux air getting past the throttle.

This test will confirm either way mate.

[Paul Woods]

just to confirm,all current v6's running with poc'd ISCV's are idling perfectly with no stall issue and no high idle so this problem is uniquely to fizzys car at the moment.

[Paul Woods]

one things for sure tone,we'll get to the bottom of it as per usual mate.

[Enthalpy]

Sounds very similar to the hotspot idea for intake manifolds that use a carb.
btw, welcome Enthalpy, i didnt get a chance to say hi before. :thumbsup: :)
Hi! I feel very welcomed in this community. It's a pure pleasure to be a part! Thank you for the warm welcome.

[Enthalpy]

I daily drive a 3VZ-FE, circa 93 on the stock ECU. Mind if I throw some ideas out there?

It seems odd to go IMMEDIATELY into safe mode upon resetting the ECU and restarting. Most safe modes require a driving cycle, unless you have a connectivity issue with a sensor.

Vacuum leaks (including those between the airflow meter and the throttle body) will represent a leaner mixture. If your engine races, that indicates it's too rich.

The ISCV system kicks off when the IDL and E2 circuits make contact in the TPS. This is the place I would start! There is an adjustment here.

Something else to realize - The stock ECU carries a "learned idle" map inside that puts the ISCV where it thinks it needs to be. When you reset the ECU, you lose this. You are now having to re-populate that map. The stock ECU does NOT immediately repopulate that map, it requires a driving cycle. As such, your throttle and any bleeds will contribute to the idle speed.

The thing I'm keying off most here is the fact that you idle LOWER when COLD. This tells me the ECU isn't doing ANYTHING to control the idle (because IDL and E2 aren't shorted in the TPS). When oil gets cold, it's more viscous and introduces a larger DRAG on the motor. Without an ISCV system, you would see higher idle speeds when warm.

Let me know if you have tried any of these things. I'm going to go break in an airplane motor now, and then EMS a Turbo-ed Hyundai Tiburon. I will check back tonight (middle of the night UK time).

[Fizzy]

This why I'm all confused...

Before :-

"Classic" symptoms. Idles high on cold start, pretty quickly dropped to 1.2k, then once it started warming up (about mid level) would drop to around 500-600 rpm. During this stage, if I was driving the car it would usually stall at junctions etc.

Once warmed up, would stay at around same level, but not stall. Every now and again, if I sat in traffic etc, the revs would slowly climb up to the "normal" level of around 800-900.

Understood that this was pretty much what everybody else with stall issues was getting? First idea of a solution was adjust the throttle stop (which I didn't do).

After:

Got new ISCV off ebay. Sent to Paul for pocvip'ing. Installed - now idles at cold/while warming up at 1-1.1k rpm. As it gets nearer normal operating temp, idle revs climb - to reach about 1.8k rpm when warm. Definately doesn't just go straight up to 1.8 as I saw it at 1.5 beforehand etc. :confused:

Reset ECU - no effect after a few runs, restarts and the like.

Put old one back on and more or less back to normal - although now idleing at expected levels (which it did very, very ocassionally before).

Its annoying as the only thing that has been changed is the ISCV... so thats why I suspected an issue with the "new" valve. Last few refits I've even used gasket sealant with the metal gasket to make sure no leaks there.

Hence why I'm confused as to why an issue would appear now if it was a leak etc. Arrrggh!

Ah well - something else to check over at the weekend.

...and on a side note, when stationary, I get a lot of noise from the clutch or gearbox. Goes away when I push the clutch in, but comes in when released (obviously when it neutral and engine running ;) ) I would say thrust bearing, but a new one was fitted at the same time as the new clutch during the conversion. Could this be a bearing in the gearbox on its way out? What bits still move when clutch engaged but car not in gear?

...and why am I getting a group of problems all at once when it was going so well before? (Obviously not a serious question - just a moan. ;) ).

[Fizzy]

Just a thought - would a lightened flywheel change the noise/feel of the engine? Perhaps its just because with the lightened wheel its not putting the same load on the various bits which are in use, hence a few odd/different from normal sounds...

..... or is that just a load of rubbish? :idea: My engine has done over 200k after all...

Anyhow - still using the old ISCV at the moment, and have not gotten around to trying the new ISCV fully closed without the cable connected, as Paul suggested. Nasty weather the last few weekends has stopped me from doing anything on it, and the next few weekends I've got plans - so looks like this will be a while before I find out exactly whats up.

On a side note, I believe I have sorted out the whole "engine still running while in reverse" thing. Refitted the engine bay fan ecu tonight, and hooked up the ground from that to the ground wire I found buried in the loom (which I tested before hand and it is definately a ground). Now engine bay fan acting as it should, reverse lights are fine and the whole "engine stuck on while in reverse" issue has gone.

Think I still need some new spark leads though, or I'm maybe suffering from water ingress into the end spark plug hole in the same way Peebs was. A couple more little jobs to do yet then I think... :thumbsup:

[Paul Woods]

whats the reverse light anomoly? never heard of this one before?

[biteme]

It's an anomaly with the reverse lights.

I have a fat head. HTH. lol

[Fizzy]

whats the reverse light anomoly? never heard of this one before?

Something specific to my car. If I was in reverse gear (with clutch in obviously ;) ) when I switched the ignition off, the engine would not cut out. As soon as I knocked it out of reverse it would cut out. People have also commented in the past it looked like my reverse lights were slightly on at times....

...after tracing cables, checking circuit diagrams etc I traced it down to a problem with the earth/ground wire coming off the engine bay fan ecu. Has now been corrected. :D

[Paul Woods]

ah cool! thats a new one! not so much of a fuck up but a design feature fizzy lol

[OlberJ]

It's a turbo timer.

:mrgreen: