HybridKOOP

GS-R powered del Sol, DRAG Gen 3 kit, stock motor, .45 bar of boost (only making 5 psi since downpipe was connected to cat), RC310's, 255 intank, DRAG inline pump, B&M regulator, VORTECH 8:1 FMU, timing stock, NGK plugs gapped to .035.

Under VTEC point, the cars smooth as a babies ***. Turbo begins spooling great, no stutters, steady increase of power. VTEC hits at 4400, power dies.. and the car struggles to make power to redline. 1st gear is NOT affected by this problem, it rips straight thru to redline... all other gears, VTEC hurts. Too much fuel?

I disconnected the VTEC solenoid and drove it. SMOOTH all the way up, but less HP obviously with no VTEC lobes.

What gives?!? Could the car have too much fuel pressure between an intank 255 *AND* the DRAG inline with RC310s??

lucas569

play w/ the gap, i was having trouble all week. turns outmy gap was too small, everyone on here says .30-.35.

my car runs best at .40, anything below this and the car feels like it hits a wall in vtec.

HybridKOOP

You may be right, because the car tore *** before I gapped them down to what everyone said to (.030). .030 was terrible.. So I brought them up to .035... I still think the factory gap of 1.1 was best.

HybridKOOP

Anyone think that using a 255 intank pump AND the inline DRAG fuel pump with RC310's is too much fuel? Would taking the 255 out and putting in a stock intank in be a good idea?

lucas569

you know i might go w/ 1.1 myself just to try it out, i think w/ signifant boost it will be too high but not under 6 psi, imo. i guess ill find out

ekb18c

I think your running way to rich! What your fuel pressure at?

HybridKOOP

It's not my car... I just did the install. I turned his regulator pressure alllll the way down to 36psi with hose off (as low as it'll go) and it's still rich I believe. Think I should yank out the 255 intank and put a OEM intank in?

ekb18c

Either that or just yank out the inline pump and leave the 255 intank pump. UP to you, I know the intank is easier to swap out though.

X2BOARD

I am having that SAME exact problem. Although it's an LSVT with an OBD2 ecu, I was thinking the ecu was messed up. My gap should be about .35 and the car pulls fine till 4500 or so, then feels like it bogs bad... basically hit vtec and the car slows down ! I finally get some vtec mojo going at about 6.5K to 8K... but what's the use ?

A little point... strange, but true... the car performs IMMENSELY better with an LS ECU and nothing else being changed... same fuel pressure, plug gap, timing, etc... but pulls like a champ ! No vtec tho...

Did you notice a bit more power for the last 1000 rpm or so before redline ?

X2

Speed PHreak

1) VTEC ECU's dump fuel and run rich in VTEC..so i'm told. Prehaps it's running you super rich in the lower RPM's and finally leaning out enough to make power above 6.5K

2) If you can move your VTEC point higher, my mini-me doesn't hit VTEC till 5K.

HybridKOOP: I'd pull a few degree's of timing and lower your static fuel pressure a bit...see what that does for you.


[Modified by Speed PHreak, 3:38 PM 8/9/2002]

X2BOARD

Oh, I did advance my timing a bit, which made quite a difference, but the bog is still present in early/mid vtec... but opens up in the top.

So should I also follow the thinking of downing the static fuel pressure a bit, as the ecu should richen in vtec ?

Speed PHreak

What ECU are you running for you LS/VTEC?

X2BOARD

I am currently using a 2000 GSR ECU. (today, my original 97 LS ecu....which seems to treat her better)

Speed PHreak

1)Is that GS-R ecu chipped or something? remember the GS-R have that f'd up dual butterfly intake manifold. VTEC actaully engages at 4400 RPM, but then those secondary butterflies open up at 5700 or so. I'm sure the fuel curves in the ECU reflect this somehow. Possibly since the secondaries don't open up till 5700(more air, more fuel), but VTEC comes in at 4400 you could be starving you engine between those 2 points if you're using a regular intake manifold......Does that make any sense? I'm not sure if that helps any...

Tell me you're not using the GS-R intake mani?


[Modified by Speed PHreak, 4:59 PM 8/9/2002]

X2BOARD

I'm running a B16 head and mani... The GSR mani does have the dual runner and (I believe) the ecu has some type of control over it, but I don't believe the fuel maps are different between 4400 and 5700.... I wonder which forum I should post that question.... I did consider that possibility, but most have told me it's no different with a b16 mani...even tho the dead spot in vtec more or less coincides with the rpm that the second runner would not be oeprating. The GSR is not chipped, BTW.

X2

HybridKOOP

X2Board... EXACT same situation... car feels great to 4400, hits a WALL when VTEC engages, then begins to want to rip a bit from 7000-8000rpms...

I'm going to put a stock intank pump in like DRAG recommends, leave the inline the way it is, and regap the plugs to .40 and see what it does. I think both of our problems is just too much fuel...

CovertFI

you have the ability to change your fuel pressure, so that can lean or richen your mixture. so how would removing your extra fuel pump help your situation? if it could even be the fuel pumps fault it would run like **** all the time not just in a certain window. Leave the pump in there!!!

X2BOARD

Yeah, the wall we are hitting in vtec definitely feels like too much fuel...but since I don't have any gauges installed right now.. I can't even begin to guess.... heh heh never thought a cheepy A/F gauge would look soo attractive !


The turbo needs to go back on, so I want to have my minor fueling and ecu problems fixed before I start any other wrenching.

I will do some tinkering this weekend as well.... if I find anything, I will post it up... it would be great if you do the same !

X2

HybridKOOP

Like my previous posts stated, the fuel pressure atthe regulator is ALLLLLL the way down, and still is too rich -----> which I am attributing to *TOO MUCH* general pressure at the rail.. no matter how low the regulators turned down.

VaporTrail

you need to retard the timing to at most 10 degrees. That'll help I'm sure. 8 to be safe