1998 Spanish build Vitara questions

[Ivan_J]

G16b? is it 16valves with MAF, or just MAP sensor based engine.? G16B 16V w.MAF
is car OBD2 or OBD1 , ECU, if latter are flash codes 12, in both modes (LPG and Petrol) I'm not sure. It have all three service plugs: 4-pins, 6-pins and OBD2. But not all scanners can connect it. No error codes recorded.
is your iSC 2 pins or more, some newer engines have motor drive isc and egr. ISC is same as http://www.fixkick.com/sensors/tests/IAC-E-tests.html Cleaned and tested.

yes, a conversion, duel fuel
and you have smart egr, with egr motor driver. it runs with or without cat.
the egr runs , when not at idle, and not w.o.t, and is regulated as an electric motor, via , engine rpm and load.
load on this engine is a function of MAP ( MAF if it is) readings. like when going up a hill vacuum is lower, and that means load is greater.
the egr flow is most , from map readings. and the egr is just a motor controlled valve.
the ecu injections (petrol) are based of tables, of RPM and load.
so the LPG, brain must be tuned from those large tables. and is not easy, and will be crude, unless its done on dyno long hard work
id bet your LPG brain (L-ECU) is crude, like most are in the conversion business.
the petro (P-ecu) thinks its running petro and is not (in LPG mode) so LPG is weaker, and the P-ECU sees that weakness and adds fuel
Its not working like this. As I said it reads petrol injection times and recalculate them to make LPG injection times. The car runs at LPG like on petrol. I don't think petrol ECU understand something's different.
It see this via the weaker Map readings
this L-ECU is what racer call a Piggyback, (a liar box)that spends its whole time fooling the P-ECU.
No there are no feedback to p-ECU

the spark advance freeze jumper only works with idle switch closed, and rpm near 800 and hot engine. if the idle is wrong, freeze fails.
there is no Suzuki published statement ive seen that shows upper limit. to failure.
so dont use the freeze , in LPG mode, only Petrol mode.
I use freeze just to adjust timing. On LPG 10 deg static advance.
back to idle . being too high in LPG mode
It's not too high in LPG, its same on petrol. And just when the car is in motion. When still, idle drops to normal within few seconds.
what will cause this. ?
Guessing,
1:normal for the ecu, if it does it in petrol and LPG mode? some software oddity, for smog reasons.
2:induction air leaks, and iSC is running near closed. we find this by doing iSC duty cycle tests. not at 50% duty hot, idle. When I clamp ISC hose, idle rpms drops.
3ticky ISC. (its not bad egr, because that cuases low rpm and misfiring)
4: in limp-home, mode then corrects that and idle wakes up. (limphome cancel idle controls) What's that?

unplugging ISC when idle is too high ,can show cause. is this a 2 pin ISC or more pins>? 2-pin


10 points on the most interesting post here ever, dual fuel. wow.

id check duty cycle of the ISC, hot, idle 800, for 50% if not 50 set it there, need photo of your throttle body. top I don't have duty cycle meter. TB is same as all 16V with plastic adjustment needle.

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"Can I plug that EGR?"

you mean unplug?
or block passages.?

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id bet the egr is needed on petrol but not LPG
unless running very expensive high octane petrol

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"Can I plug that EGR?"

you mean unplug?
, or block up passages.

I want to isolate EGR from engine but ECU don't have to know that. I'm thinking to make new gasket for passage to intake that have no hole for gasses to pass and that way I will remove EGR. I don't think ECU can catch this? I can't see any profit of woring EGR on power or economy. Just on ecology.