ok 2 problems with my car main one is petrol injector timings are all over the place....car is duel fuel with svi and using the lpg software i can monitor the injector pulse. in petrol mode the svi ecu acts as a pass through device an is showing (petrol) injector times as around 3ms on the passenger side cylinders and around 6ms on drivers side. now with a wide band o2 on the passenger side im running lean as hell, havnt tried drivers side once settled times are around 4ms all 8 cyl. this problem happens during warm up at idle an does make the engine rough an may do so for a minute or 2 until all sudden it comes good again. its deff not a missfire an leads an plug are all new. harmonic balancer has been removed an checked an appears intact. have checked for vac leaks. my second problem is i cant seem to get any code output. i bridged the first pins on the plug, an with a test light on pin 5 to ground but i get nothing. the fan does come on for cpl seconds upon ignition then nothing. so i seem to be stumped.

Your test light(I'd use a LED to keep the current low) needs to go to 12V not ground....STO is a low side drive.

ok 2 codes 327(egr) i know means nothing an 176(system lean) which i know since im using wideband. tested iat sensor which is fine an testing ect as we speak but so far looks ok reading 3k ohms at warmed up temp

327 is supposed to be EGR shorted to ground so you might want to fix that.
The 176 with LPG is usually due to your LPG running stoic @ 15.7:1(at least it should be) which means the EEC is always seeing it as too lean. Does this SVI system have any form of simulated HEGO output to spit back to the EEC? This would help matters.

If you could tune the EEC(with a J3 adapter) and change the parameter Z_AFR (Stoichiometric A/F Ratio) to LPG you likely wouldn't get this problem but you would then need to retune the SVI system not to add pulsewidth to the original 14.7:1 target of the EEC on petrol.

both codes were generated after reseting the ecu an driving for say 15min petrol only. the car has no egr as its a ute, has the plug on the loom but does nothin car has always had the code. svi has o2 pass through an correction but was neva set up(by gas installer) o2 isnt even conected to svi, i recently obtained the lpg interface an using wideband was attempting to retune more precisely untill i notice this lean running. im starting to think the ecu may be shot as after lpg was installed i had idle fluctuating problems an i ended up changing afm and tps and isc. this idle problem also reocured during the short drive while stopped at lights. just interested to know if eec can lean off one whole bank of injectors even tho they all run seperately as what i observed is momentarely injector times on one side of the motor are almost double the other side causing one side to be rich an one lean.

Yes the EEC can lean off banks separately. Is it possible that the LPG install has some picked up one HEGO and not the other?...seen this happen before. You might also check they haven't messed up the wires to and from the injectors through the injector driver box?
btw, not all utes don't have EGR.

nah deff no o2 on lpg problem is on petrol an gas so i know the petrol ecu is the problem or suspect, i have however sent an emulated narrowband signal to the pcm from the wideband controller shouldnt be problem but who knows.

What to one HEGO input on the EEC? that would cause problems unless you can spit out stereo signals?

the drivers side o2 is connected to ecu as normal, passenger side has emulated narrowband from wideband controller seeing as i removed the stock sensor to put the wideband sensor in. this way ecu sees 2 o2 signals as normal. my afr from cold start is 12ish an quickly sits around 14.8 sometimes hits 15ish but during this intermittend problem where car starts to idle rough slightly afr goes upwards of 22:1 and during this time pertol injector times are diff from left bank to right. my ecu is 7taa is there any similar ecu i can use to try seeing as i figure its going to be hard to get hold of the exact one not many utes end up in the wreckers.

Yeah I've seen that simulated O2 input cause problems before. At the very least you should switch sides to see if the problem follows that bank. Have you got the simulated signal ground tied to the actual HEGO ground wire?
From memory 7TAA is a manual. Try a 6DFD from an EL.

simulated o2 is grounded through the power source as the o2 grounds through the exhaust being 3wire sensor. guess i will have to swap the sensor ova to drivers side. best way to describe the roughness is similar to when u do ig timing an u get the rough part before it smooths out. u almost hear a click an all sudden idle smooths out like a switch has been hit. revs dont really drop either during this time.

Which is similar to a lean miss which, apparently you have.
That switching sounds like the EEC is going from closed to open loop because it can't bring the fueling into line.
Does the output from the WB have a HEGO ground wire? If so stick an eyelet on it and bolt it to the manifold bolt that the actual HEGO ground is bolted to...it may help.
Do you know if the HEGO's are good? I'd probably remove the WB altogether and just concentrate on your narrow band readings or, weld a separate bung in for the WB to keep it completely separate.

wideband sensor was new first use is a bosch type cant rem. will try swaping but yeh didnt notice any prob before hooking up really only using wideband to tune gas system better but never made it that far

Not entirely correct Pete,
Remember the o2 sensors read lambda, well the narrowabands switching point at 1 lambda, this being the stoic point which the ecu translates back to petrol AFR @ 14.7
Petrol physical mass at stoic is 14.7
LPG physical mass at stoic is 15.5

As long as the lpg system is tuned correctly and is running stoic, the petrol ecu will see 1 lamda, which it will translate back to petrol AFR because it doesnt know any different, ie 14.7, even though the physical mass in the cylinders is 15.5:1, so it really makes no difference to the ecu.


cardy - id also recommend connecting the stock o2's back, and installing a seperate bung for the wbo2. Reason being the narrowband signal is a very low voltage, and if your wideband emulated output, or its relative ground, has any inaccuracy, or voltage drop then it will affect the afr the stock ecu see's, therefore the ecu will try adjust its fuelling accordingly. 0.1v is enough to make a huge difference.
Also disconnect the battery for 15 mins or so and then reconnect and start the car, and monitor your petrol pw's. they should be roughly equal, bank to bank. Then see how they change as the engine warms up and ecu goes into closed loop. if they drift when in closed loop you could have a bad o2, or even a vacuum leak. Get the petrol side of things spot on first, then worry about adjusting the LPG. How old are the o2's?

If your wideband is set for petrol, then tune your lpg to target 14.7 on the gauge, if its set for LPG, then target 15.5. Or switch it to lambda and tune for 1 on either fuel.
You can run LPG lean, it wont do any harm, just that the motor wont make the power.
Ideally if you want max performance from LPG you need to adjust your spark map to suit.

thanks heaps for the help have checked for vac leaks, an yes bit unsure bout the narrowband emulated output as its .1-1.1v i think but maybe adjustable. will run with just standard o2 for now and both o2 are near new b4 gas was fitted.