Engine problem... can't idle update with pic...

[Mr X]

ok, bad times for me :/
The Idle problem in the video has been coming back with vengeance!
The car will run fine for a week and then run like this for 3 days and I'm running low on ideas.

I have now replaced:
MAF sensor
o2 sensors
Crank sensor
camshaft sensor
water temp sensor
timing chain
chain tensioner

I checked throttle position using torque and that seems fine.
Battery volts are ok

Ive checked operation of the OCV
By plugging in another OCV (leaving one installed) I can see it's stalling because the ECU is sending +volts to the OCV and causing the engine to almost stall. Then it cancels the +volts bring it back to normal rpm.
Unplugging the OCV while running makes everything seem to run fine. Tho this does disable timing advance circuit and throws ECL.

I am now at my whits end as to what the problem is... Why would the ecu try to advance the timing and cause the stall when idle? The only thing i can think of to do now is rewire ocv + sensors in the hope this is a broken wire. Although, how would a broken wire cause this behavior?

Any more input would be a great help.

[Die$eL]

I may very well be Way off here, but whats the chances that the computer box is gone a bit haywire?

As you say, the motor is stock, and it seems you have changed every single sensor.

I have a 1ZZ turbo running Apexi PFC. After the engine rebuild it was still fine. Then I had it mapped again for all the new mods and it started doing this. (vid below)

http://s30.photobucket.com/albums/c344/Diesel111/?action=view&current=VID00005-20120605-0753.mp4

I'm going back to the tuner to have it mapped again. I increased the idle speed by 100rpm and that did help a great deal but it still does bounce like that a little. Mine only does it when i come to a stop after driving. does it for about 5 seconds and then stabilizes to 900rpm idle.

[Wabbitkilla]

I may very well be Way off here, but whats the chances that the computer box is gone a bit haywire?

As you say, the motor is stock, and it seems you have changed every single sensor.

I have a 1ZZ turbo running Apexi PFC. After the engine rebuild it was still fine. Then I had it mapped again for all the new mods and it started doing this. (vid below)

http://s30.photobucket.com/albums/c344/Diesel111/?action=view&current=VID00005-20120605-0753.mp4

I'm going back to the tuner to have it mapped again. I increased the idle speed by 100rpm and that did help a great deal but it still does bounce like that a little. Mine only does it when i come to a stop after driving. does it for about 5 seconds and then stabilizes to 900rpm idle.

Funnily enough after the last "attempt" at mapping my PFC, mine started doing this ... .basically the rpm's bounce up & down as you slow to a stop with the clutch pressed. Once at a standstill idle control takes over and it stabilises. I was thinking it could be the crank position sensor ... but now I'm wondering if it's some setting RS Tuning changed. Even though I restored the Noble map and settings it still does it.

[Die$eL]

I may very well be Way off here, but whats the chances that the computer box is gone a bit haywire?

As you say, the motor is stock, and it seems you have changed every single sensor.

I have a 1ZZ turbo running Apexi PFC. After the engine rebuild it was still fine. Then I had it mapped again for all the new mods and it started doing this. (vid below)

http://s30.photobucket.com/albums/c344/Diesel111/?action=view&current=VID00005-20120605-0753.mp4

I'm going back to the tuner to have it mapped again. I increased the idle speed by 100rpm and that did help a great deal but it still does bounce like that a little. Mine only does it when i come to a stop after driving. does it for about 5 seconds and then stabilizes to 900rpm idle.

Funnily enough after the last "attempt" at mapping my PFC, mine started doing this ... .basically the rpm's bounce up & down as you slow to a stop with the clutch pressed. Once at a standstill idle control takes over and it stabilises. I was thinking it could be the crank position sensor ... but now I'm wondering if it's some setting RS Tuning changed. Even though I restored the Noble map and settings it still does it.

I'll keep you updated once i have mine remapped. it'll only be in about a month or so though...

Please drop a line if/when you get your's sorted

[Mr X]

Thanks for the replies guys. I does look similar as what's happening to me.

It can do it on:
start after ecu reset
starting from cold
starting from hot
never does once the car has been started and running ok (mid drive)

and then sometimes, It could run fine. Just like it did today after work. Really confusing!
You guys could try to disconnect your OCV and see if that stops the idle bouncing like it does mine.

Tonight seen as I can't look at it (it's running ok) I modified the 2zz OCV to be the same as the 1zz OCV. Next time It does it, i will swap them over. I'm sure that's not the problem but at this stage, anything goes! lol

[Mr X]

Well, I don't want to jinx things but last night I took my 2zz OCV, took it to bits and back together to be the same as a 1zz OCV.
Hey, it's worth a shot even tho ive tested the ocv out the car and while runnin (+12volts = stall). Seems to run a lot smoother now! So far... no funny idle!
Touch wood, fingers crossed etc... see what happends over the next few days!

[Die$eL]

I hope that sorts it out!

Here is some useful info i found in a Toyota book about the sensors on the 1ZZ

[Wabbitkilla]

Mine actually has a new OCV in it, it was misbehaving before fitting it and it's been misbehaving since fitting it ... i.e. it makes no difference. Admittedly there could be several causes for a fault that appears to be similar.

[Mr X]

Thanks for the post Die$eL, I have those drawings from different locations in my bookmarks. Now I can see them in 1 post  s;) s;)

It started doing it again last night.   s:evil: :evil: s:evil:   So that is the OCV out of the questions. What's left now is the actuator to check (hoping to be able to jiggle the bolts out without removing the side cover and look inside), the wiring and ECU.

That said, it was doing it before I fitted the OCV and stopped after. However, while under the car I looked up from underneath (front of the gearbox side) and the loom runs into a square box/channel. You can see the loose wires inside. While under there, i poked my finger in, gave them a wiggle and diss/re-connected the ICV. Maybe it started working well after as there is a part broken wire in that box that i disturbed!

I've wired my spare sensors up with bullet connectors. Once this dam rain stops and the idle is funny, I'm going to install them 1 at a time and bypass the loom. see if i can see what wire is broken.

[Cap]

I'm late to the Party here.. ( don't go over the Pond Much..  )

The Cyclic Rhythm of your Idle is a 'Loop Imbalance' ( or Loop Hunt ) of the ECU trying to get the Idle Speed proper..  you have changed and checked most of the Things Involved..  

A few things that come to mind that you have missed, or not reported as being Checked..  

1) Exhaust leaks..  If the head to Header gasket is leaking, it will have a Major Effect on O2's at Idle..  might be an Issue.  
2) PCV Valve..  it is a Calibrated leak, with a Spring that will open and Close with Varying intake Vacuum, might need to be replaced or Bypassed for testing..  

The Idle Speed is Set by the IAC Valve ( In the T-Body ) but then it is Finalised by Changing the Ignition Advance..  

During Open Loop Cold Start, the IAC will go to a Pre-Determined Set Point, and the Calculated Mixture will be Biased upon the IAT and Coolant Temp.. and the Ignition Timing will go to about 10 BTC for stable Idle, and Retarded Spark for Exhaust heating..  The MAF is ALWAYS used open or Closed Loop..

When the O2's Start to work, and the Water temp is not warm enough, they will be ignored. After the Water Temp is warm enough for Stoch Mixture ( 14.7 ) then the Fuel Mixture is placed into Closed Loop, and the O2 are used for Mixture Control..  

All the Time the Engine is warming Up, the Ignition Advance is Increasing, and the IAC is closing down a little to keep Idle Speed..  After Some Target Temp, ( Closed or Open Loop ) the IAC will go to it's Preprogrammed Position, and the Idle Speed is controlled by Ignition advance alone..  

To Eliminate any O2 Sensor/Exhaust Leak type of 'Induced Hunt' you can Pull the O2 Sensor Plugs while is is Running in Closed Loop, and see if the 'Hunt' Settles Down..   Upon first pulling the O2 Sensor wires the ECU will have to do some quick thinking, to figure out that it is now in Open Loop..  so there will be a little Unsettled Time, but the ECU should settle back down to the Business of Keeping Idle Speed..  

If the Pulling of the O2 Sensor Plugs Settles the Hunt, then LIKELY it's an O2 Sensor/Exhaust leak problem.  

If the Hunt Returns, then it's LIKELY a Vacuum Leak like a PCV or a Fuel Vapor Canister vent line, or Solenoid problem..  

I do have MANY loggs I've done of My Stock 1ZZ ( USDM ), so my observations are based in facts..  

Good Luck on your Search..  

Cap

[Wabbitkilla]

Interestin.

1. Closed loop idle is ok.
2. Cold start idle is ok.
3. Idle is only unstable when returning to idle for high revs driving .. i.e. Idling to a halt.
4. I could block the pcv line to see if that makes a difference.
5. MAF has been replaced.
6. vvti OCV and filter have been replaced (precautionary).

I would expect and IAC, PCV, or Carbon Cannister fault to exhibit idle problems during cold idle and closed loop idle.
No leaks that I can find in manifold, or exhaust, definitely no tell-tale noises either.

The engine does have 104K miles on it now and this winter will see a timing gear over-hall, it will be interesting to see if that makes a change. Some variable has changed during the life of the engine since the original mapping, I guess wear in the timing gear or sensors could induce that change of delta, obviously using closed loop idle allows the PFC to control that.

[Mr X]

Thanks for the reply... that's some more food for thought.
I have felt for leaks in the exhaust and have none.
o2 sensors have been replaced even tho it would do it when cold.
I did test the large pvc hoses and the smaller dia ones going from hard pipe > canister > valve > throttle and were ok. I replaced them with silicone ones to double make sure. I tested the vsv valve for ohms, some airflow without +12v and free airflow with +12v. All seemed ok so negated that as a problem.

one thing i didn't test was ICV as I have the problem on part throttle (If I put my foot on the gas and hold at 3k rmp it will still drop the revs still). when I get under it again to look at the loom, I will have a look at this too.

[Cap]

I was studying your Longer Vid, and the Displays you were showing..  
The Ignition Advance and the Fuel Supply, will Hunt up and Down with the Rhythmic Pace of the Hunting, at Idle..  but at the 2K RPM I do not see either the Ignition or the Fuel variations..  

That tells me the Ignition changes are LIKELY a Reaction to the Idle Routines of the ECU Trying to keep a Steady Idle..  and the Fuel changes MIGHT be from a Vacuum leak and the O2 Correcting for a lean condition ( Just Guessing here )..  the problem I'm having is knowing what the Update time for the Sensor to Display time is..

At the 2K RPM I do not see the Ignition Changing or the Fuel Changing, but the Speed is still Hunting ( Sounds almost like an Ignition Miss ) ..  Could it be the 'Perceived Air leak' is not enough for the O2's to react to before the leak 'Corrects' itself?..( So no Fuel Changes)   and the Fact that the Hunt is present at Higher Speed will rule out an IAC problem, as the amount of air passing through the IAC at 2K fast RPM is minimal..

I'm thinking Plug ALL the Vac Lines to the Engine..  ( Including the Brake Booster ).. and see if the Hunt Stops..  

Are you Factory ECU or PFC?..  

Cap

[Mr X]

Everything is standard engine/ecu wise apart from new manifold and silencer.
it makes about 5 total reads per second (every time the green light flashes). If you want to see any displays that you think might help me, I can do another video.

I have been paying more attention to the way the thing drives and have noted:
 Probably 15% of the time, it's a good smooth drive and good idle at 850rmp... I can tell when it is ok as it sounds fantastic!

75% of the time, it's a little jerky while decelerating/accelerating on slight throttle. Idle can be slightly lumpy at about 780rpm. It will also pop and bang from the exhaust on almost every gear change or lift off the throttle.

the 10% of the time it tries to idle like the video. sometimes it worse and really drops, sometimes its just noticeable. It stinks of fuel and you can see it spitting out of the exhaust when its bad!when it runs like this i pull out the plug for the OCV, i get a CEL and then the car idles fine.

what's worse is I'm only getting 16.4mpg!!

I have read through what you have advised. I checked:
5mm silicone pipes I put on to the vsv.
Air cleaner hose to throttle body.
PCV hose to throttle body.
PCV hose to intake manifold.
none have holes/cracks or leaks when i tested them.

Replaced the PCV valve for the one that's on my 2zz.

The car seemed to run ok after it was back together but i didn't find any problems so   s:? :? s:?
I didn't try to block any pipes as it was running ok before i took it to bits.

Thanks for you help! Mark

[Cap]

Your car has been a very reliable problem..  I doubt if the Dificulty has completly vanished..  they usually return..  Don't like your fuel millage..  I'm at 36 MPG on the Highway ( Motorway )

Wondering..  If it might be an Electrical Earthing problem..  causing the Various Sensors to give bad readings to the ECU,..  the Picture you posted of the Crank Sensor was a little to white and furry for my liking..  How about checking the Earth Points on top of the Transmission, next to the head..  Might have something to do with it..  

When I was asking for the Vacuum lines to be plugged, I was not Suspecting they were cracked, I was cautious that some Valve Somewhere might be opening at the wrong time, causing the Machine to act up..  If you COMPLETLY block off all vacuum Lines then that Likelyhood is removed..  

So far it's been a good Hunt..  

Cap

[Mr X]

36mpg is a dream for me ATM. This all started just as I gave my 2nd car (206 HDi) to my sister, now I only have the Mr2 and feeling the fuel bill hit!

haha That is just kitchen roll I shoved in at the time to catch the oil.

I did think that it could be an earth problem.... If you look at the image below:


I cleaned the points at EA (chassis) EB and EC (2 on the side of the block). I then ran a 10mm core earth wire (one i used to power an amp) to these points and hooked it up to the - terminal. So they are not only earthed via the  car chassis, but also directly to the battery! Admittedly, I haven't touched EA1 and ED. That said, I did wire the earth to the crank sensor directly to EA1, didn't fix the problem either.

Today, the car ran 100% ok this morning and when I went out at 1pm. However, it started to rain at 3pm and when I left to go home at 5pm It had the "dipping" idle.
I unplugged the OCV so it idled ok and drove home. Once I got home i shut off the car, plugged in the OCV, cleared the fault codes and started it.
It then didn't dip the rpm but it was a rough idle, not smooth....

maybe I have water in the loom some where and it's corroded a wire? the heat dried it out a bit so it wasn't as bad but still ran pants....
I think I may just go on a hunt for a 2nd hand engine loom. Swap it over just to take that out as a possible cause. It is a good hunt but not much left it could be! haha
Mark

[Cap]

You have been fixing the problem by Pulling the OCV Plug.. that will toss a cell lite, and causes the lumpy idle to stop..  

Try this..  next time the Lumpy Idle starts, pull the Cam Position Sensor Plug insted..  it will cause the ECU to do a 'bank Fire' on the Fueling, and a 'Wasted Spark' for the Ignition, but the Car will otherwise run fine..  It will not have the ability to do any VVTi work, as the Sensor for the Cam is missing..

Just wondering if the Lumpy Idle will also stop then..  looking for varables..  

I do not think the wire harness will change anything..  and from what I've been told, to change the harness in the Car involves the creation of new sewar words..  

Can you get a hold of a Wideband O2 Sensor?..  If SOMEHOW the Earth Offset from the O2's to the ECU is bad, then the O2 Sensor Sig to the ECU will be displaced either up or down from ideal..  if you can clamp on a Wideband, and you are not running 14.7 while the ECU is in Closed Loop, then an Earth offset MIGHT be an issue..  you'd have to catch it while it was Lumping, or the test is no good..  

You could mount a wire to the Engine Block, and another one to the white wire of one of the O2 Sensors ( on the Sensor side, not the Car Harness Side ), and run these two wires to a Digital Volt meter..  the Offset should be Almost ZERO..  If you leave the Digital Volt meter hooked up while driving, and when the Idle starts to act up, look at the meter..  see if the Offset Changes..  This could have some relation to the Alternator causing a Earth offset Voltage?.. Hey, I'm dragging at straws here..  you've checked EVERYTHING else..  

Cap

[Mr X]

yeah, it stalls because it sends +volts to the OCV valve while idle. I found this out by disconnecting it and plugging in another valve. sure enough, the valve operated. I then connected wires to the plug then to the OCV. I stripped a section of wire in the middle and connected a volt meter. The ecu sends 6v to the valve and the cars rpm drops, then back to 0v and idle back to normal.
I also noticed, as the cars rpm drops, Torque's timing advance display jumps to -10deg for a split second and then back to 14deg (or whatever). This also happens when ocv is disconnected to force the car to disable the timing advance circuit. I'm not sure if the display is measured timing advance or commanded timing advance.

OK, i will try to tug it out next time, it's in a rather dodgy position!

From what i can see, the loom isn't that bad! I've had it to bits so many times now, i reckon i could do it in an hour or 2. Only problem part is getting the connectors for the oil pressure and crank sensor off as they are connected to the dip stick half way up the front of the engine.

Would this be an issue when cold? I thought the ecu ignored o2's unit warm?
hey, anything is worth a shot mate!
Thanks again for all your help with the car.... I know all Toyota are going to do is ask me to throw money at them!

[Cap]

The O2's start working in about 30 seconds.. as they are heated..  the ECU will start using them in about 120 to 240 seconds..  depending on Coolant temp, and IAT..

I'm thinking checking the Earth Reference between the Sensors and the Engine..  thats why the Digital Volt Meter..  Actually I'm more interested in the offset voltage between the ECU and the O2 Sensors..  I really do not care where the Engine sits Electrically..  but the Engine is used as a Return path..So if it's Offset then likely some electrical issue is at play..  then the narrower hunt begins

The OCV is a Pulsed 12.. so the 6 Volts you were reading was some 50% cycle Square Wave..  and the meter was reading 6 volt..  the OCV is not usually cycled at Idle.. as the Cam and Crank are in the proper VVTi position for idling..  usually you can pull the OCV plug and not change the Idle at all..  just the Cell will come on..  not sure why yours is strobing the OCV at Idle..

The ECU does 'Pulse' the OCV Coil to test if it's actually hooked up..  I've never hooked a volt meter to my OCV to see if the Volt Meter will see any Voltage..  looks like I have a Task to perform..  

Cap

[Mr X]

haha yeah, I guess they would heat up that quick! Often I have ran the car for under 60 senconds and burnt myself on the exhaust thinking it would still be cold!

I have set aside this weekend to work on the car... I've even brought one of those flood lamp stands with 2 200 watt flood lights on them! No garage for me :/

I will test the earths as I have a digital volt/ohms/current meter, have another look at what the ecu sends to the ocv, loop some wires round to the sensors and see what happens.


The car ran ok today so still haven't had chance to pull the camshaft plug. I also rang Toyota up and spoke to their "top guy" in service. I explained to him what's happening and he said it is unheard of! He said normally they have to replace o2 sensors, the odd MAF and gunked up/warn VVTI actuators (part on the cam). Without a cell to go off, whatever is going on can only be a minor thing for the ecu and can't see it as a problem.

[Mr X]

Well, yesterday was a nice day so I thought it would be a good time to de-wrap the hard top and paint it instead.
I sanded it, washed the car and then took the hard top off to let it dry before painting.

While it was off I had better access to the ecu and loom. I popped the cubby hole out and look what I found:



The the drain hole was covered by a razor blade   s:? :? s:?   and some sort of bung! also, the pipe was full of sh!t...

The thing has been running ok all week but I haven't washed it like I normally do!
once i cleaned it all out i pulled the top up and put the hose on it for 10 min. The water still comes in but it seems it's coming from behind the soft top cover rather than leaking pipework. Just above the inter-connectors between the engine main wire and engine room wire! These are the orange and white in the photo.

I covered the loom in plastic to shield it just in case.
Next time it rains I will have a peek to see what volume of water is getting in.