RomRaider

hey guys ive recently installed some deatsch works 650 cc injectors ive changed my flow scaling to 647cc due to that this is the lowest flow for one of the injectors after instal and tune i watched my wideband and it went strait to 16 and stayed now not to my concern i waited for the fuel learning to take place and still nothing 16 constantly lean wtf so im stuck now and im all ears for any ideas

I'm guessing you didn't put all the vacuum hoses back together properly when you were finishing up the injector swap.

Could also be latency related depending on what ROM you currently use.

well i have the perrins fuel rails and this made alot easier when changing injectors i checked just a sec ago all hoses and plugs are in correctly whould not having a bigger fuel pump be the problem call me dumb but i bought the car pre modded so im not sure if they changed it

Under what conditions does the wideband read 16?
Idle?
Cruise?
Engine braking?
WOT pulls?

The fact that it "went straight to 16" after being tuned makes me wonder if it's just doing that while engine braking - because it's perfectly normal for the AFR reading to get maxed out under those circumstances. Most read 20 or so, but you didn't say which wideband you have.

well i was scared to drive it it just idled at 16 way too lean so i was scared to drive didnt know what would happen its like the car couldnt even learn the lean out conditions

Did you take any logs?

no logs i didnt drive the car it just ran like crap and too lean i bought walbro 255 today and ill just install it when it comes in

Really sounds like a vacuum leak. Double check all of those hoses.

i was wounderin is if the stock fuel pump would be an issue i didnt move any hoses and i just put the stock injectors back in retuned it back to stock flow scaling and it runs like befor hummf

hey guys so i got my fuel pump in today only to realize that i already had a walbro in the tank yay .... so i swaped it with the new one anyway i redid all of my vacumme lines today aswell just to make sure there all in correctly i didnt notice anything wrong with any of them so now im stummped that dw injectors are suppose to use the stock latencys and ive put the recommended flow scaling in so im really really stumped anybody have this problem befor PLZ help

Almost every deatschwerks injectors I have installed used a scaling 10% to 20% lower than the size of the injectors. If you had 16 afr I would start with 10% lower.

That is because stock injectors are scaled at 520 or 500 in the OEM ROM, but DW says they flow 540 or so.

Even Subaru can't decide what they flow!

They may be supposed to use stock latencies, but stock latencies don't work right. They are too low.

See this thread:
topic4149.html

Most likely you just need to tune in your:
- injector latency table
- injector scaling
- tip-in enrichment table

Don't listen to what is 'supposed' to be right. Listen to what the car is telling you. The car is telling you that it is not right.

I got this from David D when I asked for latencies, 650cc top feed.

Please see below for our latency testing bench results. Please note these
numbers are just a guidline to get you started. In most cases, further
adjustments are necessary to the latency settings...


Latency
volts Milliseconds
7 3.3
8 2.6
9 2.2
10 2.0
11 1.8
12 1.6
13 1.5
14 1.4
15 1.3
16 1.2
17 1.1

For my fxt 09 edm, this is the values I ended up that works quite well. I did however have to rescal .9 to 2.54 of the mafv table to get my af learning at -5, -2, 0, 0



Update: Working well, these latency values do get more fuel in but can be controlled via mafv scaling to get desired ltft. Im not seeing erratic low load fbkc anymore using the same timing.

*Just a pita to scale mafv for af learning a 0 to 5.6 g/s. Keeps on running too rich, started out at -16%. Now Im maintaining between -4 to -5 for A.

Update July 30: I went with just +15% across all volts. This was previously recommended by Gabedude when I sent him a pm. Recommended latency values give too much fuel as seen on my logs using the MP spreadsheet. Now Latency is working well and Im staying with this. Previously I was already close at just plus 10 and I compensated with Mafv.

What Im trying to figure out now is why Im getting slight fbkc (-1.4 to -.7 which is normal for e10 gasoline) at low engine load. This was non existent with using the latency given by DW. Advice?