Im having an odd issue and ill start from the beginning.
I built the car b20v 12:1. tuned it quickly on crome and left it
The tune was never good, and i assumed my 240cc injectors were just too small to keep up. the best afr i could ever get was like 13.5(im shooting for 13) and then it would rise to redline.

So i just recently bought a set of DSM 450s. and wired them up.
10w 10ohm resistor on the yellow black wires at the injector side of the harness.(so i know they are the right wire)

Car has a walbro 255, and a new fuel filter.

Pulled the tune i was using to drive it before i adjusted for the injectors. .533 multiplier required 60 offset to run right.

Made a pull. 13.5. added some fuel.....13.5 added some more.. 13.5
Added so much fuel it should have not ran in the high cam.. no change.

I dont see 450s not keeping up with a b20v 12:1 motor on pump gas. i could be making at the most 210whp.

The walbro should handle it just fine. (ive heard possibly that it requires a relay for the pump)

I dont have a fuel gauge (and my fuel filter doesn't have a service port)

Anyone ever had an issue with crome being the problem here?
Ever had a walbro not keep up with this low hp?
If i lean it up it WILL lean out. its just like 13.5 is the RICHEST it can maintain during a wot pull.

Any help would be awesome.

 

Maybe your fuel pump is getting weak. You need to get a fuel pressure gauge on there to see if your loosing pressure. It has nothing to do with crome.

 

the pump isnt even a year old. not even 10k miles on it.

 

You gotta start somewhere. Noone is going to be able to diagnose you issue online with the little info you have. You have a fuel issue somewhere and it's not the tuning program period. Check fuel pressure, voltage, ect. Its called process of elimination

 

no i understand that. The issue i have is no fuel pressure gauge. and not even a service port to tap into. just trying to figure out what other checks i can do. or if anyones ran across this problem too.

 

I just told you what to check....

http://m.ebay.com/itm/300876032168

 

Also get rid of those resistors and put a resistor box in there

 

I appreciated the link.

 

i would like to know why a resistor box would be any different than wiring dedicated resistors inline? its the same function

 

don't worry about what he said. as long as they are 10ohm 10watt ceramic resistors, they will be fine and operate exactly the same. the key is that they need to be 10watt resistors. 1 watt resistors simply will not suffice.

you can easily add a fuel pressure guage port by drilling and tapping the bolt on the fuel filter. (edit: nvm, just clicked the link above)

 

yeah they are 10w 10ohm from radioshack like everyone gets.
gonna get a friend to ride with me while i make a pull and measure the voltage drop at the pump(if there is any). see if mabye its a draw issue.

 

pump gets 11.9-12v the entire time. i made a pull.
Odd thing. i adjusted the injectors to a 310cc and the car runs a lot better. 13.1-13.4 afrs. but adjusting the fuel tables does nothing on the high cam side. i can tune them on the law cam cruising. but nothing i do high cam works.

 

do the numbers in the map actually change when you richen up the cells? or do they not even change value?

 

they change but AFR is not affected

 

are you using crome pro or crome gold, and datalogging through crome?
are you sure you're changing the correct cells? have you tried highlighting all of columns 8, 9 and 10 and adding 10% or 20% fuel to all simultaneously?

might be dumb questions, but I've seen people do some pretty weird stuff before without fully understanding what they were doing

 

lol i know what you mean. and yes. i have tuned all my cars prior to this one, and know a decent amount about how/what to tune. Ive tried adjusting from 4inches to .3 psi fuel cells just to see if mabye my map sensor was off. nothing. i could make the fuel cells high enough to be 100% duty cycle and the cars afr doesnt change. But it seems the high cam is the only thing thats not changing. Its like its reverting to stock but when it switches to high cam.


Im using crome free, and im not datalogging.

 

And in case someone is thinking wideband is off..
I can at idle. lean it fully out and make it full rich i have full sweep of range.

 

looking into it. im wondering if mabye the fact that i have the vtec pressure sensor bypassed, if it would cause it to not "sense" vtec on and not switch the maps. any body have any thoughts?

 

try adding 30% fuel to that entire area in the low cam map, see if it richens up. if it does, then for some reason it's still reading from the low cam map and not the high cam map

 

Gonna do that today. i wonder if in crome free you can add rpm increments? im not at my computer with it. or are those settings locked.

 

there may be a plugin for adding rpm rows, revtools maybe. not sure if that works on the low cam though, or only high cam.

another thing to try is disable vtec completely and see what happens. you should be tuning the entire low cam map to at least 7k anyway before even getting into the high cam map, so might want to look into that.

are you even sure if it's going into vtec or not? physically, or electronically?
are you sure you're using the correct chip addresses when burning the chip?

 

this is being done with through the emulator. emulator/chip has the same outcome/tune.

I mean. i hear the crossover. and the car pulls extremely harder lol. so im positive its going into vtec physically. i just dont know if it its electronically(?) lol. i have no vtac light.

 

well if it is going into vtec physically, the ecu must be sending out a signal to activate vtec. so the real question is whether it is or isn't reading from the high cam map, and why.

might need to completely uninstall crome from your laptop, and reinstall a fresh version. sounds like there might be a bug in it somewhere or something.

try disabling vtec first though and tune all of the low cam and make sure lal that functions properly. then re-enable vtec, try again. if it still doesn't work, keep vtec enabled, but try adjusting the low cam fuel values and see if it alters the afr

 

tahts what ill do. Im also gonna add the vtp vts remover onto the tune. i dont think that was on there.. i didnt know if mabye the ecu gets a reference back saying."hey im on, switch your maps"

I did the uninstall. and reinstalled the newest version.
I guess for now im going to try tuning the low cam fully out and see if it is staying there. will know more in about 3 hours. lol

 

From what I gathered by the quick read, you're having an issue with bigger injectors and crome doesn't like anything bigger then 440's honestly. Crome is buggy and when it comes to bigger stuff, I no longer offer tuning anything that's bigger then 310's on crome. You'll need to first set your injector battery offset, crome does have this option.

Under advance tables, you can find it, from there, I've never found anything in the fueling system to work right, Where it has old injector/new injector, leave old injector sizing at 240, and then move the new injector sizing, 440 probably wont sit right, but i'd try 400 and see how the car acts. More then likely, you're reaching the limit of the table in crome and it "thinks" you're running out of injector and your not, gotta tweak the map setup so you're not.

Call me if you need else, i'll be happy to help - 225-384-1441.