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cutting out when coming off throttle


Adzn3k
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hi people,

I'm in need of a little help, i have installed an 2azfe turbo in to my celica gt4 using  a fury g4+ I used the fury basemap and changed all the settings to suit the 2az and the dbw setup I'm using. I runs great and is driving fine however it cuts out when coming to a stop of coming off throttle, then when it is started back up it revs up of a second or so then drops down to normal idle.

I've done a log (attached) from taking the car to be aligned the only way to keep the car running is to keep my foot slightly on the throttle. any body care to have a look so i can get some run in miles in before getting it to the dyno.

FEW FEWEL TWEEEEKZ.pclr

the log file is too big to upload here unfortunately can email if needed, i'll try get a smaller log 

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https://www.dropbox.com/s/qhwazaru0thq3ax/back from allignment.llg?dl=0

https://www.dropbox.com/s/j45ha50b1qjt5nk/alignment run out.llg?dl=0

Hopefully that works, the back from alignment shows pretty much it cutting out then when firing back up it revving high for a second or so the second one is a much longer log that shows it happening a few times but i did spend alot of time keeping my foot on the throttle to keep it alive. 

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Fixed up a few things in your map.  Turned on idle ign, fixed the base position table and the E-throttle target. reduced RPM lockoutr and increased deadband, It should hopefully work better. 

The other thing you need to fix to prevent the stall is the wheel speed sensor.  It is not working in your log.  Without this the ecu will start closing the throttle trying to control idle during overrun and this may cause it to stall.   

FEWFEWELTWEEEEKZ idle changes.pclr

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Cheers for that, I didn't think about the wheels speed sensor as the clocks on the dash work I'll sort that out today and try this new map out then report back, 

 

Thanks for the help 

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I've just been out and wired the speed sensor up then fired it up to go for a little drive but it randomly cut out it seems to be a trigger error.

This trigger error has been showing up since the beginning causing a couple of errors at low revs and it showing the revs jumping up on the datalog. I've tried to capture it on the scope but it never happens when I try to replicate it. The cam and crank sensors were new when I built the engine and also the wiring is correct I'm assuming its something to do with the arming threshold maybe?

**EDIT WRONG LINK***

thats a log of it happening

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https://www.dropbox.com/s/rshcwg38wounz69/cut out.llg?dl=0

 

I went out in the car earlier and once the car was warmed up the trigger error seemed to disappear, maybe the new sensor doesn't like the cold? other that the car drives fantastic now idles great and no cutting out when coming to a stop or off the throttle. 

One last thing is it correct that if I hit boost cut the ecu will cut the dbw? on my drive earlier the wastegate's boost reference pipe wasn't by mistake connected so the car hit boost cut and the the ecu turned off the dbw relay.

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I was looking at a log and I think it might of been from the to main seeing over the error value I assume that could have caused it

The problem with that trigger error I have tried many times to capture it but i can't replicate it when I'm setup to check

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Your cam pattern is retarded quite a long way from the expected pattern and also comparing to "known good" 2AZ trigger scopes on google yours seems very retarded.

Can you pull the cam cover off and check the cam timing looks correct.  Also check the thrust journal at the front as these can apparantly break on the 2AZ.

Note you need to lock the cam gear to check timing as per this doc: https://static.nhtsa.gov/odi/tsbs/2012/MC-10133978-9999.pdf

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The timing was correct as per the instructions as its marked on the timing chain. I will check to see if the gear is locked on the weekend. I do have a set of BC cams to go in so may just set about installing them. 

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Here is your scope compared to a "known good" 2AZ from one of the diagnostics groups Im in.  Notice the position of their cam teeth in relation to the missing tooth gap on the crank is moved about 8 crank teeth to the left compared to yours.

Several other scope pics I found on google seem to suggest theirs is normal and yours is not.  

 

SCjP28A.png

DD4jycd.png

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I will have a look, it's pretty tight in the bay so will have to see what I can do without dropping the engine, I do have 2 spare cylinder heads with cams so if needed and if I can get the cams out without dropping the engine I will probably look at putting in the new cams with a newer vvti sprocket from the spare head 

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All being well I'll be able to have a look at the sprocket and timing this weekend and have a good vvti sprocket ready to go in if needed. I do however think that the trigger error is More to do with the sensor as it only seems to happen when just as the engine either increases speed or slows down. I have a new sensor coming this week too

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3 hours ago, Adzn3k said:

the intake cam being locked retarded can't be the cause of this issue surely 

Your cam is not "locked retarded".  Your cam teeth are approx 80 degs further retarded than it should physically be able to move.  

The problem is the cam edges (pink lines), are sitting just about right on top of the sync edge (yellow lines) and move across the sync edge whenever the cam moves a little.  

image.png.389cfbc65982ceb73c6f1961ec620019.png

 

If you compare to the known good pattern, the cam edges will never cross the sync edges:

image.png.05a5eb2d1694f37b97129af06eb74b79.png

 

 

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Right I've been doing some investigation, 

 

I was told that the vvti should unlock when oil pressure is applied to it so I ran the car up turned the output to test for the vvti and immediately the car miss fired and cut out. So to me that would suggest the vvti gear isn't locked I tried again whilst logging and it cut out so there is must l definitely be movement in the vvti gear.

I have a feeling that maybe the trigger wheel is on backwards on the crank that could be causing this issue With the retarded cam signal? 

I'm going to test this theory out a little bit later when the local traffic has calmed down by disabling the vvti all together and see what happens

 

I'll add a link to the log of it cutting out when testing the vvti shortly 

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