the.hamburglar

ok this is kinda of a long story, but ill make it as short as possible. i had an old lsvtec with about a 10.5:1 compression ratio with the gsr pistons and stock head and ls block. i had it tuned to perfection with dsm 450's and crome. it ran a 13.3@110mph on street tires. the tune was about 22* timing from 5500-8000 and about 11.5-11.8 afr all the way in boost.

anyways i wanted something faster so i just built an ls vtec with 81.5mm arias pistons and eagle rods and the whole head since it was off. i now have an 8.57:1 compression ratio.

so im done my break in now so today i started to tune...hit boost and go over 4500rpm. however i started off with my old map from the 10.5:1 build mentioned above and now in boost (4psi) at 5000rpm i cant get it to richen up at all. i keep adding fuel and adding fuel...im over 90% duty cycle now at 5000rpm and its stilll a 14.9:1 fuel mixture. will a compression ratio make this much of a difference? i thought for sure i would be able to use 450's for 7psi boost. can anyone give me some guidance as to whats going on?

ps, im still getting some blowby out the valve cover breather at idle, i didnt get any with my old motor so the only thing i can think of right now is that the machine shop might have messed up the bore so some of the oil is mixiing with the gas upon compbustion and creating a lower octane level for the fuel. could this happen?

So Cal So Boosted

What is your fuel pressure at? Check your fuel regulator or fuel pump.

the.hamburglar

ya thats another thing i was thinking about since it has been making some weird noises lately becuse iv let it almost stave of fuel a few times (fuel light has come on). i dont now what my fuel pressure is at . no way to really check without a gauge hey?

GetawayInMoscow

Sounds like your O2 sensor is done to me...

the.hamburglar

haha, its funny that you say that. its got less than 50 miles on it. i just got a new one, bocshe has lifetime warrany on all their wideband products. im thinking it has to be my fuel pump because the mixture is always around 15 no matter what the idle is or rpm,

alpha

Double check the wideband. Try a new fuel pump. Resistor box is wired in correct?

CoreyR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by the.hamburglar &raquo;</TD></TR><TR><TD CLASS="quote">haha, its funny that you say that. its got less than 50 miles on it. i just got a new one, bocshe has lifetime warrany on all their wideband products. im thinking it has to be my fuel pump because the mixture is always around 15 no matter what the idle is or rpm,</TD></TR></TABLE>

if it just reads stoich all the time its your wideband. if you give the car a quick rev in neutral it should go richer for a second till the idle stabilizes. if it doesnt its the wideband.

which wideband is it? some need to be recalibrated more then just initial startup.

So Cal So Boosted

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by the.hamburglar &raquo;</TD></TR><TR><TD CLASS="quote"> i dont now what my fuel pressure is at . no way to really check without a gauge hey?</TD></TR></TABLE>

As far as I know, you would need a gauge. I have one on top of my fuel regulator, that I check periodically.

the.hamburglar

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alpha &raquo;</TD></TR><TR><TD CLASS="quote">Double check the wideband. Try a new fuel pump. Resistor box is wired in correct?</TD></TR></TABLE>

you think the display is just not working right?

the.hamburglar

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CoreyR &raquo;</TD></TR><TR><TD CLASS="quote">

if it just reads stoich all the time its your wideband. if you give the car a quick rev in neutral it should go richer for a second till the idle stabilizes. if it doesnt its the wideband.

which wideband is it? some need to be recalibrated more then just initial startup.</TD></TR></TABLE>

no its not just stoich. however it will read between 14.5 ish and even into the 19's. its a plxm300 with a new bosche sensor

So Cal So Boosted

What do your plugs look like?

If you have already been running around with the set, it might be a little to late to read the plugs. But if they where brand new before you started it up, I would check them out.

Supacharge

this may be a long shot. but the exact same thing happened to me:

i was tuned on crome (400ish whp) and upgraded my setup for more around 600whp. howard at RLZ was tuning the car on crome for the new upgrades. the car would not respond at all. same problem you are having. kept adding fuel and nothing. we couldnt even make a full dyno pull b/c it would lean out every time. he was completely stumped at the time and tried everything he could think of with no luck.

finally, he went and pulled out hondata s300 and tried it. problem fixed. fuel was added, car richened up, and have ran hondata ever since.

we still dont know why the crome wouldnt repsond to the car. it was like a "freak" thing i guess. it could be possible that yours is doing the same thing mine was ....

batboyvaj

i was bout to mention crome being the issue.

BlackCRX

get a fuel pressure gauge
replace fuel filter??
what size fuel pump?? if its stock then you might be maxing it out
larger injectors??

90dxhmt

iTrader: (1)

Eliminate the mechanical possibilities first get a new fuel filter and grab a Russell fitting part #640700 it replaces the bolt for the banjo on the filter giving you a 1/8 npt port for a gauge so you can see what you have for fuel pressure.Do you have another car to test your wideband on to check it?

the.hamburglar

thanks guys for all the ideas. i kinda do think it might be a crome issue. im going to try some more things tonight. the thing that stumps me the most is that the only things i changed was valve train, rods and pistons. i had my 450's working great before. crome was datalogging perfectly and i had no problems at all.

can someone give me a link to an older version of crome. when i start it up its giving a weird error that i should check for updates

the.hamburglar

NEW PROBLEM!

so i this evening i go to start up my car and let it warm up for a minute until i started to drive it. while i was letting it warm up i watched the wideband and it no longer stays around 15 afr. now it shows 14.64...14.67...15.04...15.1...15.2 etc slowly until it hits 20 and then the display shows lean.

so my question is this...is there a way to recalibrate a plxm300 wideband or do i need to buy a new display?

the.hamburglar

oh ya one more thing...i guess it could be my fuel pump because its not able to flow the amount at idle so it pumps very little. i think i need to get a gauge

BlackCRX

how does the car feel when its idling and the wb shows lean??
does it surge like its going to do??
or does it idle the same as before??

you might have a bad sensor

the.hamburglar

i have a brand new sensor. no the car runs great. i can smell gas once i added 30% fuel to the map. i think its my guage and display.

boosted k20

did u pull the motor out to install the rods in the motor? check all ur grounds, esp the on on the thermostat.

i never had an issue like that with crome. it must be something mechanical....

does the ecu adjust to other changes in crome?

the.hamburglar

ok guys thanks for all the help. i know crome is working right because i can smell how rich its running when i added 30% fuel. anways a friend let me try his out tonight and im getting a 11:1 idle when i had about 14.5 before i added all the fuel. so his is right showing 11:1 and mine always shows around 15.5:1 no matter when...even in boost. so im going to replace my whole unit tommorow and put that 30% fuel back where it belongs!

quicksilver1689

glad you figured out the problem!

eVo05

im having the same issue, no matter how much fuel i add, its not showing up, the wideband is new. I couldnt get it to boost past 8psi without leaning way out. My FPG is reading 80 psi at idle which is really strange, tried 2 of them and it reads the same. Tried a new fuel filter still cant get the fuel there, I have 660cc injectors and a 255 fuel pump. Also when a 12v power source kicks on(fan, headlights) the idle drops and it leans out, they tested my alt and batt and said everything was fine, my grounds are fine but still nothing. Any suggestions please help !! i want to boost this motor at 18psi!!!

HiProfile

evo05, sounds like you need better wiring to your pump, or the person who tuned your car did a very sloppy job adjusting the battery voltage offsets. I can be idling at 700rpm, switch on AC & headlights whole opening the windows and sunroof - and be perfectly fine. You should also to modify the stock FPR (or get a new one if its aftermarket) so you don't have high pressure at idle. The endyne site has a page showing how to mod the stock FPR somewhere.