Afr Rich on electrical load

[Devon]

Hi there I am new to using link and have an issue im trying to resolve,i have a da6 integra that was converted to obd1 from obd0 with a converter harness.all works has been working fine on several different ecu's for many years its is  running a b18c turbo.i have recently purchased  a set of 880cc siemens injectors and a link g4 + 95civic link plug in. All is working well apart from at idle and on light cruse when the engine fan turns on or head lights the engine stumbles like a miss fire and air fuel ratio on the wide band goes rich from 14.9 to about 13.8 .also sometimes coming to a stop the engine will stall if the rpm comes down too fast.. I have been supplied dead times from the supplier and according to them have never had to change these dead times for any vehicle they have fitted them into. I did notice that my voltage does drop about .9 of a volt.. thanks any advice would be much appreciated.

[Adamw]

Map and log will be the quickest way forward.  https://www.youtube.com/watch?v=_P1LRANeO4A

 

[MagicMike]

.9V sounds like a bit drop

[Devon]

hi there I may have to check the loom for bad connections and maybe replace alternator.here is my map file and a log with engine up to operating temp idleing .Head lights are turned on atabout 20 seconds then turned off at 30.and back on at 40 seconds then engine fan turning on at around the 1 min mark..also the issue is not there while the engine is warming up. I did have the afr showing on the plot but after saving and reviewing it has disappeared. thanks help much appreciated.  

integra.pclr

afr rich with head light or fan.llg

[Steve]

Have not looked at the log yet but... Check if you have the same voltagedrop at the feed wire on the injector itself. Could be that your ecu ground isnt good enough and you get a voltagedrop seen only by the ecu. The ecu would then up the pw on false data making it go rich

[JMP]

To me I'd say the injector deadtime figures are not correct or you have a grounding issue.  In your log you can see the deadtime spike when the voltage drops, when the deadtime spikes your engine slowly goes rich and then recovers to normal AFR after the voltage is back to ~14V.
Looking at the deadtime table, in my opinion the figures are likely to be guestimates with a 0.1ms step per 1V from 12 to 14V instead of actual measured data.  There is some Siemens data in the link help file you can reference, I'm not sure what the 880cc part number is but the Siemens 3105 look like they might be around 880cc at 3bar base pressure.  In the link Data they have a 0.058ms deadtime step between 13 and 14V at 45psi base pressure, which seems more realistic

When I'm dialing in/confirming deadtime I use a big DC power supply in place of the alternator and run the car from 11V through to 15V watching the AFR while keeping the engine in consistent load sites, if there is an AFR swing then the deadtime is adjusted to keep it consistent.  This has worked quite well for me resulting in an excellent deadtime table and rock solid AFR's through the voltage range

[Adamw]

Those dead times in your map dont look right to me.  Below is the Ford Performance data sheet for the 80lb long Deka.  That is assuming fuel press is about 39Psi, if it is different then you need to mulitply the deadtimes by the FNPW_OFFCOMP number for whatever pressure you are running.

[Devon]

Thanks for all the help.just wondering if that would be the same for the stubby 875cc deka.

I am currently trying to get the part number for the injectors from the supplier..it is running 40 psi fuel pressue and does not change with voltage.i will try these dead times and see if any improvement. also over the next few weeks I will check over the loom and check voltages at injectors and ground points.

 

[Adamw]

Here is the data for the short deka 5's, this is for 43.5Psi so close enough.

[Devon]

hi there I have changed the dead times to match the table above.also checked over the earths to the ecu. added 2 extra earths to the engine and battery.replaced the alternator and battery still much the same.it is ok till it warms up..only thing I have left to check are the power supplies to the ecu..I did have trouble with this ecu when I first got it.was sent for repair as it was trigging two injectors at once and was a solder joint that had bridged two injector drivers.just wondering if maybe something inside is causing this issue.

thanks

[Adamw]

Might need a new log.  

 

[Steve]

Dont want ground leads flying all over the place. 

Search youtube for ground hygiene and both Andy Whyatt and Andy Whittle. 

[Devon]

hi there thanks for the help. ended up being the ignition dwell control.has stoped the misfire and only drops 0.1 afr richer.wich I presume is allgood