i started tuning on my built motor today and was noticing that it was idleing in the number 5 and 6 rows of hondata i included a screen shot

the setup is a fresh rebuilt lsvtec
running e85
wiseco pistons 9.5ish to 1
eagle rods
supertech valves,springs and retainers
gsr cams w/stock cam gears
skunk 2 intake
and a go autoworks race turbo setup
the head has fresh valve seals and all the other seals in the motor were replaced when it was built also i might add it was like this before the turbo kit and i am using a p30 base map with the fuel trim changed for my i.d injectors... im also having a issue of the bov not opening when the throttle is released (using the unpainted 11lb spring iirc) but i am sorta thinking it has to do with the vacuum in idle issue... thanks ht

 

yep, thats right. you are idleing around -20 inch of vac.
to set it up like your thinking it should be, click on options up top, then click settings, then go to your units tab. from there, in your "vacum unit base" spot, click on "atmospheric".

 

you need to adjust the map scaler somehow. the engine does idle in the -18 to -22" of vacuum normally. most engines do. you map scalers are out of wack.

im pretty sure you can adjust it so that it easier to tune/follow.

 

crazy thing is in my stock b16 crx it idles in rows 1 and 2, im not super new to tuning but this is my first time tuning boost on a honda with hondata so im overly nervous... thanks for the advice tho also when i change it to that it shows 10.5" which i thought was kinda low for gsr cams

 

Bump

 

Yeah, you are idling in the correct portion of the map but your scalars look backward. The vertical scalar value in column 9 should be in column 1 and vice versa.

 

Wrong. grndcont is correct. He's idling at something less than 10 inches of mercury.


Mister Crane, A complete lack of vacuum at idle is alarming, but likely something mundane. Do you have a valve or three too tight, out of time, AFRs completely out of wack? Start with a compression test, you should be in the 170 psi range.

 

182 186 185 181 were the compression numbers 1 to 4

 

Sounds super healthy. If the mechanical timing is off it can't be by much, and truthfully I doubt it's off at all.

What sort of wideband readings were you getting? Have you had a chance to sync your ignition timing?

 

14.ish to 1 but I'm trying to get a better base map but even 12 to 1 at idle was the same vac reading I used the Hondata option to lock timing and it was idleing around 800 when I set it not that it matters and I'm using a digital timing light from advanced auto

 

Okay, that's confusing so I went back and re-read:

If you make any positive pressure and then release the throttle, even if you have poor engin vacuum the differential between intake tract and intake manifold should release your BOV. This makes me go Hmmmm, sort of like Arsenio Hall only my fingers aren't as long and I'm kind of a rosy red complexion.

Is your MAP sensor tee'd off of the BOV pressure source? Because I think you have a leak in the signal lines that is messing up both, or at least that's what's most likely at this point and what i would check.

 

Do you have the proper Map Sensor selected in the parameters, good known sensor, wired correctly, etc...?

 

nope the bov has its own source, i have a map sensor that is mounted on the throttle body, i hadnt switched to my gm 3 bar yet. this motor did the exact same thing with idleing in the 5-6 rows of hondata in my other car but stupid me didnt try to trouble shot it then , im gonna try swapping out the sensor just in case because with the other motor in there it idled with 20+" of vacuum so i know its not a wiring issue

 

problem solved, its amazing a 5 cent piece can keep a 5k+ dollar motor from running right

needless to say i feel like an idiot... getting around 21.7" of vacuum at idle now and the a/f ratios are easier to get right.. now if i can just figure out why my bov isn't opening??

 

Those damn o-rings. Glad you figured part of it out.

 

Good work. After seeing enough ridiculous stuff go wrong, if it were my car I'd be happy it was just a silly o-ring.

Keep us updated on how the car turns out, I know you've got some nasty cars in your family.