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High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

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High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

Old 05-05-2006, 04:51 AM
  #1  
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Default High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

Hey guys gotta a car that has got a lot of ppl confused, looking for some answers, hope you guys can help.

90 integra
LSvtec 11.5:1 running 3.5lbs of boost
built motor
T3 off of a SVO
tial 38mm
2.5" exhaust
initally running on chrome, getting no where, tried hondata S200b, still getting no where.
440s
OBD1 conversion


When we finished the car, we had issues with the ostrich communicating with my laptop and the ecu, but once we got that little COM port error figured out, we thought we were good to go.

Loaded a P30 base chrome base map to the ecu and start the car up on the dyno. Run the car up through the gears. The A/F's in vaccum were consistant around the 13.5-14.0 with little change.

With the compression and the size of the turbo, we were starting to see spool up by 2200 rpm and full boost by 2800. As soon as the car would see boost the A/F's would start to drop fast to 10.8-11.5 range, but as soon as the car got near the 4000 rpm mark, the AF's would sky rocket to the 14-15.0 range.

We did a bit more checking around on the car and the tps seemed to be slightly out range, so we adjusted it according to honda's specs and went at it again.

Ran in to the same problems. Do a 4th gear run on the dyno and the car will dip below the 10-11.5 range under 3000rpm mark, but as soon as the rpm's start to climb, it goes excessively lean.

Finally, just to elimate a software issue, we plugged in a hondata s200b system to see if it may alieviate our problems, no same deal.

checked the map sensor, swapped distributors, swapped in different injectors, tried a whole slue of things.

The car is being tuned on a dyno dynamics dyno, so we have the capability to load the car and what we have noticed is should we roll the car into boost the AF's will stay at a steady 11.5. But if we do a 4th gear run at WOT, it will rocket lean. potential TPS failure

further load testing showed:

3.5lbs of boost @ 2000rpm AF: 11.1
3.5lbs of boost @ 3000rpm AF: 12.5-12.7
3.5lbs of boost @ 3500rpm AF: 13.5+
3.5lbs of boost @ 4000rpm AF: 14-15+

sorry for the long post but i figured if i could list everything we have done at this point, it may help in finding a solution. If i have overlooked something stupid, pls call me out on it, cuz i will go and try it and i will gladly send you parts, money dyno sheet whatever it takes to show my appreciation...i have so many hours of diagnosing time into, i dont what to look at anyone. We are trying to get this thing to the 10psi mark and we have been foiled by a measly 3.5 pounds....fck. My own boosted LSvtec crx has never given me this much grief before...

signed,

Pissed off, confused, frustrated and annoyed....lol

Jas
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Old 05-05-2006, 05:04 AM
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Default Re: High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

fuel pump? fuel filter? fuel pressure(regulator)?
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Old 05-05-2006, 10:23 AM
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Default Re: High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

thx for the reply.

i should have mentioned these things earlier.

the fuel filter was changed out when the LS-vtec swap was done, which was about a yr ago. (30,000kms)
there is a B&M FPR on the car. Fuel pressure is set to 45psi and watching the gauge on the dyno, as the car starts to load up the pressure is increasing, so there is (to my knowledge) adequate amount of fuel being supplied to the rail/injectors.

The fuel pump i am not too certain on if it has been replaced or not. Will check today when i go back out to the shop.
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Old 05-05-2006, 01:18 PM
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Default Re: High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

so are you tuning it or was it already tuned but somehow went bad?

did you try adding more fuel 4000 rpm's and up

had to ask, sorry
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Old 05-05-2006, 07:29 PM
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Default Re: High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

Sounds like a fuel pump but if pressure is increasing...it wont be that.

Could be something to do with battery voltage dropping off and your injectors not firing as hard, could be misfiring slightly and showing lean...did you try swapping ECUs? Maybe the injector drivers are giving up in that ECU?
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Old 05-05-2006, 08:57 PM
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Default Re: High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

Originally Posted by jeffsciv23
so are you tuning it or was it already tuned but somehow went bad?

did you try adding more fuel 4000 rpm's and up

had to ask, sorry
no we finished the install on the turbo kit and we were beginning the tuning on the car.

For a trial, i actually took the whole boost map after 2000 rpm and fattened the ---- out of it, to the point where should the car reach boost and hit 2000 rpm, the car should have stalled out because there was so much fuel, instead it still kept reading very lean.

dont be sorry dood, i appreciate it. We are at a loss so any theory is a good one at this point.

thx for the help.
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Old 05-05-2006, 09:01 PM
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Default Re: High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

Originally Posted by xenocron
Sounds like a fuel pump but if pressure is increasing...it wont be that.

Could be something to do with battery voltage dropping off and your injectors not firing as hard, could be misfiring slightly and showing lean...did you try swapping ECUs? Maybe the injector drivers are giving up in that ECU?
chris, i have tried:

my P28 that you chipped for me
a hondata chipped p06 converted to vtec for the s200b unit
another customers chipped P28

and all 3 are showing the same signs with little to no variation between them.

Never thought of the battery voltage problem, will give that a try in the am when i get back to the shop to play with it. Didnt see any signs of a misfire but no harm in checking it out again.

Thanks again.

if anyone has any other theories or ideas, they will be very appreciated at this point
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Old 05-06-2006, 01:22 AM
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Default Re: High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

Was the fuel feed line that goes into the fuel rail recently removed/replaced? If so, check that the small washer (the one with the serrated inside lip) is there and is the correct one.
Ive seen a car exhibit those exact same symptoms (although, they did not appear until higher in the rev range 4500-5000ish), and the incorrect washer was on the feed/fuel rail fitting causing pressure in the rail to drop dramatically at higher revs/boost. If you have a FP gauge handy, it will also show up as an unusually high FP at idle. (if tapped in on the fuel filter, pre-rail)

Just some stuff to check out.




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Old 05-06-2006, 11:17 AM
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Default Re: High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

sounds like there is a missing link installed and the ecu isn't reading into boost? have/are you able to datalog to see what columns/rows you are hitting in crome or hondata?

did you use fuel tools when setting up your basemap or adj the boost table efficency? sounds like stupid questions, but just trying to think of everything.
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Old 05-07-2006, 03:07 AM
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Default Re: High Comp (11.5:1) LS-Vtec tuning issues/ Chrome/Hondata pls help- long read

Originally Posted by quadtech
With the compression and the size of the turbo, we were starting to see spool up by 2200 rpm and full boost by 2800.
Compression doesn't have anything significant to do with spool. Especially at low rpm where the short duration low cam + high CR results in a abnormally high parasitic loss on the intake stroke. If CR has any effect at all, you are spooling 100 rpms later than a stock LS with your turbo.

Originally Posted by scttydb411
have/are you able to datalog to see what columns/rows you are hitting in crome or hondata?
Ding ding ding.

You also haven't told us *exactly* which version of Crome you are using, and *exactly* which version plug-ins you are using. Since you can replicate the problem with Hyundaidata, I don't think that it's your problem, but it should be listed so we can give specific instructions when needed.

Stop worrying about TPS, with closed loop disabled the ECU runs di-rectally off the fuel maps. TPS is just used for TPS enrichment, which doesn't work quite like some think it does (try to turn it off, or way way down sometime and see what happens).

Got any pictures or really detailed descriptions of the plugs? Which plugs are you running? Plug gap? Have you changed them? If you are dipping into the 10:1 AFRs, has it occurred to you that you might be having rich misfires? The Del Slo I had on the dyno today glazed plugs and went from 301 whp @ 12 psi the first run to 237 whp @ 12 psi the second run, with the AFRs jumping a whole point - gay!
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