VEMS Community Forum

Technical => Fuel Injection => Topic started by: mads b (dk) on July 15, 2015, 12:59:02 pm

Title: wrong injection timing ?
Post by: mads b (dk) on July 15, 2015, 12:59:02 pm: What could be wrong ? (this is a type1 vw boxer engine)

Cyl 1 and 3 have this exhaust port color (cyl1 rigth engine side)

https://goo.gl/photos/DjzcKbBQC2PzCGNo8

Cyl 2 and 4 have this exhaust port color

https://goo.gl/photos/DgZCm3fPNRFddeZi6 (cyl4 rigth engine side)
Title: Re: wrong injection timing ?
Post by: mads b (dk) on July 15, 2015, 01:00:55 pm: https://goo.gl/photos/KaqXdV67KbDFrXT58
Title: Re: wrong injection timing ?
Post by: mads b (dk) on July 16, 2015, 07:55:56 pm: config file

https://drive.google.com/open?id=0ByeSn_ZKQXVHbnU5a3ZYNmtOVWc
Title: Re: wrong injection timing ?
Post by: Machismo on July 17, 2015, 09:10:38 am: I didn't see the config file, the google asks me to log on. I don't have a google account. But a couple of points:

Do you know if your injectors flow the same? Sometimes old injectors fail partly or completely or at least very often they spray a different amount of gas because they are worn or clogged. When I have matched used injectors in a flow bench, I've noticed that typically there is are 15% differences per set, which is too much causing some cylinders run lean and other a bit rich.

Another thing that comes to mind is a vacuum leak, or in a case of multiple throttle bodys, wrong adjustment which makes cylinders run unbalanced.

Also check Base setup - Injectror Trim that all 'multiplier trim' values are 100% and 'additive trim' are all also the same, for example 52us.
Title: Re: wrong injection timing ?
Post by: mads b (dk) on July 17, 2015, 10:17:08 am: Try to look at config fil again, it should work now....

i havent flow test the injectors, by the way they are 370cc bosch ev6 injectors 0280156021

im running a single center throttlebody https://goo.gl/photos/UDdK6CR4qicFm6oq6

all injector trim should be the same.
Title: Re: wrong injection timing ?
Post by: Machismo on July 17, 2015, 11:54:08 am: Thanks, now I got the config. I didn't notice anything special with it and I'm no config expert, so I'll give you some mechanical ideas that you can try one at the time.

- Switch injectors in pairs from side to side. If the exhaust color change the other way around, faulty injectors.

- Fuel lines seem to be connected in series, which means other side gets served first. That sometimes can cause pressure difference at the injectors, so for testing, invert it, so that you're feeding the opposite side first.

- Maybe some problem with the injector outputs, change the wires from side to side to see if that is the case.

When testing individual cylinders at idle I usually over lean the mixture so much, that one or several cylinders cut out and then use IR meter to see which cylinders are colder and have a problem. Testing that way might be faster than waiting and looking at the port color after every change.
Title: Re: wrong injection timing ?
Post by: Sprockets on July 17, 2015, 12:23:10 pm: Be aware of the different airflow characteristics of the inlet as well. All is not equal ;) ideally you would run multiple AF or EGT to see what the distribution is like, but when it is clearly visible like this, try the individual cylinder offset and give those 2 more fuel.

Regards

Gavin
Title: Re: wrong injection timing ?
Post by: mads b (dk) on July 19, 2015, 02:15:05 pm: thank you very much i will try to work with this :)
Title: Re: wrong injection timing ?
Post by: mads b (dk) on July 19, 2015, 02:58:39 pm: just wondering is this the correct way to setup injector when NOT running fully seq ? or should i also tick more

ignition is 1432

https://drive.google.com/open?id=0ByeSn_ZKQXVHOGdvNnJQY1hWdWc
Title: Re: wrong injection timing ?
Post by: mads b (dk) on July 19, 2015, 07:19:20 pm: i have found a config error... im running 36-1 trigger

This is wrong https://goo.gl/photos/mG98XtqTE5mLTsMXA
This is right https://goo.gl/photos/SLcryY9D7RiLYQwd8

Maybe its a ignition timing problem ?
Title: Re: wrong injection timing ?
Post by: mads b (dk) on July 24, 2015, 01:28:04 pm: in the injector calibration gruppe i can see that the pw on cyl 1 and 3 is low than 2 and 4 why ???

http://vems.hu/vemstune/sharingcenter/reports.php?cmd=view&key=uJukim#comments
Title: Re: wrong injection timing ?
Post by: VEMS on July 24, 2015, 01:33:58 pm: Hello Mads,

Quote from: mads b (dk) on July 24, 2015, 01:28:04 pm
in the injector calibration gruppe i can see that the pw on cyl 1 and 3 is low than 2 and 4 why ???
I suspect you are looking at the individual power gauge at that time (6:30), not the injector pulse width as these are all (0-3) the same the entire log.

Best regards, Dave
Title: Re: wrong injection timing ?
Post by: mads b (dk) on July 24, 2015, 01:35:11 pm: I have a video.... I'm working on sharing it :)
Title: Re: wrong injection timing ?
Post by: mads b (dk) on July 24, 2015, 01:41:44 pm: yes i see you probaly right

https://goo.gl/photos/EwjhM8b7oLb5u7gZA
Title: Re: wrong injection timing ?
Post by: VEMS on July 24, 2015, 02:31:21 pm: Hi Mads,

Quote from: mads b (dk) on July 24, 2015, 01:41:44 pm
yes i see you probaly right

https://goo.gl/photos/EwjhM8b7oLb5u7gZA

Indeed the gauge on the left is the individual power gauge it shows the relative power difference for each cylinder (keep in mind this only provides interesting information during stable rpm), the injector pulse width = 4.1msec for all cylinders (also in your pic).
I would focus my investigation on your injectors, swapping side to side first then if confirmed having them flow-tested and cleaned. Looking forward to your findings,

Best regards, Dave
Title: Re: wrong injection timing ?
Post by: mads b (dk) on August 02, 2015, 01:48:12 pm: Hi

Update

injectors tested and are OK. But the engine response well to extra cyl trim fuel on cyl 1 and 3....

I was looking at a head from the engine i was runningoing last year... This head also have one grey and one black exhaust port (this engine was running smaller injectors)