Do I need bigger injectors or more beer!!!???

[ssvolvo]

Hello all,

It's me again. I've been dealing with a VE tune on my LS2 powered Volvo. I'm fine in the low load sections but if really loaded the absolute richest I can be is 13.5-1 A/F ratio. My duty cycle goes over 600%! So just for giggles I grabbed my wife's 06 GTO (same operating system) and made a full tilt pass down the highway logging the duty cycle and other pertinent data to see what I am missing. Same thing happens...The base pulsewidth goes up around 19ms then just jumps to 100ms for no reason. This is under hard acceleration but steady throttle(full).

This is a BONE STOCK (no tuning at all) 06 GTO.

The log is posted and if you look about frame 3136 you'll see what I mean.

Thanks for helping! John...almost out of beer.:help2:

[TAQuickness]

That is weird. I notice you are also getting quite a bit of KR for a stock vehicle. As well, seems you are able to duplicate the issue with 21% TPS (frame 3128).

[ssvolvo]

I first thought the problem was in my homeade engine wiring harness. Bought an E40 from Jesse and talked to him about my tune, because it seems to need so much more fuel than I thought it should. Then realized my power wire for engine was not big enough. Had many grounds for ECM and coils together kept getting a PO689 for low voltage at IGN1 circuit. Remedied the wiring harness and started tuning all over again. Engine draws 56 amps during high RPM/loading situation(I had no idea as I was showing 8 amps at idle with an amp probe). No more 689 code and my VE table needed MUCH less fuel in the low load regions. However the high loading brings out the lean condition. Finally got mad and added 30% more fuel in the 99.4 and 105 KP rows. Logged full tilt and major burnout, shows 600% duty cycle, and around 12.6 air/fuel. The tune looks like crap, like a ski jump.

That's when I thought maybe I was doing something wrong logging the data so I jumped in the wife's GTO (same O.S.) and that does the same thing with the duty cycle, as you see in the log. What an eye-opener...sort of like the ECM goes schitzo during highest fueling needs.

So back to the Volvo. I just did a short run with a Fluke 98 scopemeter recording fuel injector MS and that shows over 20milliseconds injector pulse at high load and over 90% duty cycle. Also with a fuel guage hooked up to the windshield wiper on the driver's side, did a quick burnout and the guage didn't even flinch off 58 PSI.

Haven't dynoed the thing yet but it feels like a strong 450hp-flywheel.
Seems like anyone I've asked about the injectors tells me they should support 450hp easily. They are stock GTO Ls2 injectors, running 58psi with the latest GTO operating system which remedies a problem with the drive by wire.

Not sure if I should swap out the injectors for a tad larger or just beat the crap out of it until it blows and buy a real motor.:grin:

Geez am I rambling or what?

Thanks for looking, John

[ls1vt209]

Sorry I can't help with this because that is some crazy stuff right there. Will be interesting to see what has caused this though.

[joecar]

You still need beer, regardless of fueling... they are orthogonal.

[ssvolvo]

Had to change sae_generic clc 905 and 906 to use GM.INJPW1 and 2 instead of GM.IBPW1 and 2.

I know we are not supposed to change these but it works for me.


Still think I need bigger injectors. Have MAXED the VE table and still only 13.6 -1


Thanks for looking guys,John

[ssvolvo]

Good afternon,

I thought I would follow up this post after taking a 1200 mile tuning trip. It seems I cannot add enough fuel to satisfy my LM-1 wide-band O2. After returning my E40 to closed loop fueling I noticed during decel fuel cutoff that my LM1 only would read down to 16:1 A/F. Usually it reads 20.8% during DFCO. Once I replaced the sensor with a new unit things are getting back to normal. I've been chasing this problem for 4 months. Bad info in = bad info out.

Seems funny how many of us have problems with the LC1, LM1 units when my old FJO wide band with an NTK sensor works every day in a daily driver with never a replacement. The extra price of the NTK sensor is well worth the money in my opinion.

My Ve table looks "normal now"! Guess I don't need as much beer anymore,:grin: John

[ls1vt209]

Good to see you sorted it out.