Snotbox wont run on petrol

[katwoman]

Bought the Q on straight gas, trying to make it run on petrol. Tank in, pumps fine. Auto-elec says ECU is fried. Got another ECU, wouldnt run on gas OR petrol.( no spark) Put original ECU back in, fired straight away on gas. Need to get it going ,so it can go back to where it come from.(ebay) Any help, please..

[Silver]

Any sign that it is trying to run on both petrol and LPG at the same time?

[katwoman]

Any sign that it is trying to run on both petrol and LPG at the same time?

Nope. wont even fire on petrol.

[NissanGQ4.2]

Was the working ECU that the car came with an original Nissan ECU or aftermarket????

Been on Gas there should be a black box that controls the gas, Is that the ECU the elec is refering 2 or the main ECU?

Do you have a switch for it, to switch between petrol and lpg?????????????

Are you trying 2 run it dual fuel or straight petrol????

p.s: keep the q and sell the u *L*

[katwoman]

Was the working ECU that the car came with an original Nissan ECU or aftermarket????

Been on Gas there should be a black box that controls the gas, Is that the ECU the elec is refering 2 or the main ECU?

Do you have a switch for it, to switch between petrol and lpg?????????????

Are you trying 2 run it dual fuel or straight petrol????

p.s: keep the q and sell the u *L*

It's the main ECU, Todd. On left floorpan. Trying to run duel fuel, with a switch.

P.S. I will just add a match..problem solved !

[Silver]

Nope. wont even fire on petrol.

In the old days of carby 302 with impco hat gas, I used to set it to supply both as an anti theft measure.

[NissanGQ4.2]

It's the main ECU, Todd. On left floorpan. Trying to run duel fuel, with a switch.

P.S. I will just add a match..problem solved !

Not that I have gas, so don't know much about how it works but wouldn't the gas computer need 2 be reprogrammed 2 run petrol???

[NissanGQ4.2]

can you take the gearbox out before u light a match???? I need me a new one of those!!!! Or if you have insurance I'll just park mine beside it *L*

[katwoman]

Not that I have gas, so don't know much about how it works but wouldn't the gas computer need 2 be reprogrammed 2 run petrol???

Ah, maybe. But I would of thought the auto-elec would of picked up on that..
Insurance ????? hahahaha, thats funny

[NissanGQ4.2]

Ah, maybe. But I would of thought the auto-elec would of picked up on that..


Do you know If the main ECU is original Nissan or aftermarket?

[katwoman]

Both ECU tried are genuine nissan ones.

[NissanGQ4.2]

why are you going 2 the trouble of changing it over 2 duel fuel if your selling it?, surely wouldn't make that much extra on sale price, esp if your having drama's with it

[Yendor]

When you are trying to run it on petrol (with the old ecu) do you have spark?

[katwoman]

Just thought it would be easier to sell.. Didnt think it was going to be this much of a drama, either !

[katwoman]

When you are trying to run it on petrol (with the old ecu) do you have spark?

Hey Rodney.. No spark, no.

[Yendor]

Are there any wires relating to the gas system going to the negative side of the coil?, or any extra/ added wires at all to the negative side of the coil?

If so just try disconnecting these and then see if you have spark, (on petrol).

[katwoman]

Are there any wires relating to the gas system going to the negative side of the coil?, or any extra/ added wires at all to the negative side of the coil?

If so just try disconnecting these and then see if you have spark, (on petrol).

Dont know, Rodney. Will have a look tomorrow. Do you think it has been set up somehow for straight gas, which is why it wont run on petrol ?

[NissanGQ4.2]

Dont know, Rodney. Will have a look tomorrow. Do you think it has been set up somehow for straight gas, which is why it wont run on petrol ?

I believe the computer that controls the gas will need 2 be reprogrammed for it 2 run on petrol

[katwoman]

I believe the computer that controls the gas will need 2 be reprogrammed for it 2 run on petrol

So, who reprograms these things ?

[katwoman]

I believe the computer that controls the gas will need 2 be reprogrammed for it 2 run on petrol

But, the 'borrowed' ECU wouldnt run pet or gas?!

[NissanGQ4.2]

So, who reprograms these things ?

next question *L* I would assume any lpg installer or a good mech with the right gear could do it

[NissanGQ4.2]

But, the 'borrowed' ECU wouldnt run pet or gas?!

is it the same part numbers on the ECU? borrowed from same year model GQ...etc???

[timbar]

are you getting fuel to the engine ??

[Yendor]

Dont know, Rodney. Will have a look tomorrow. Do you think it has been set up somehow for straight gas, which is why it wont run on petrol ?

Just thinking that something might be wired up wrong with the gas/petrol change over switch/circuit.

If you have spark when on gas with your old ecu, you should still have spark when on petrol.

The only thing I can think of at the moment is the negative side of the coil is being switched to earth when on petrol.

By temporary removing any extra wires from the negative side of the coil (leave original wires) will confirm or deny this.

[katwoman]

is it the same part numbers on the ECU? borrowed from same year model GQ...etc???

Apparently, it doesnt matter ??!! have heard conflicting views on this subject.


are you getting fuel to the engine ??
Yup.. Pump working and fuel coming out of hose..

Just thinking that something might be wired up wrong with the gas/petrol change over switch/circuit.

If you have spark when on gas with your old ecu, you should still have spark when on petrol.

The only thing I can think of at the moment is the negative side of the coil is being switched to earth when on petrol.

By temporary removing any extra wires from the negative side of the coil (leave original wires) will confirm or deny this.

Cheers Thanks Rodney. I'll get the old boy onto it.. It's another avenue to look at.

[NissanGQ4.2]

Apparently, it doesnt matter ??!! have heard conflicting views on this subject.

maybe it doesn't, but considering the original ECU works on gas, and the borrowed one doesn't then one would assume it does make a difference.

was the borrowed ECU borrowed from a working vehicle???

[katwoman]

maybe it doesn't, but considering the original ECU works on gas, and the borrowed one doesn't then one would assume it does make a difference.

was the borrowed ECU borrowed from a working vehicle???

I am told so. yes.
WHere's that match ??

[NissanGQ4.2]

I would try Rodneys suggestion first,

Also forget about the borrowed ECU, If the car runs on gas with the original ECU then there is nothing wrong with it as far as I'm concerned

[Silver]

I am told so. yes.
WHere's that match ??

High speed gas BBQ with off road capability......

[NissanGQ4.2]

How did you go Kat, is the GQ still about or has it been burnt out??? *L*

[growler2058]

Ive got it!!!!.....................Try speaking nice to it instead of all the insults ahhahahahahahahahahahahahahaa

[NissanGQ4.2]

Ive got it!!!!.....................Try speaking nice to it instead of all the insults ahhahahahahahahahahahahahahaa

ahhahahahahahahahahahahahahaaahhahahahahahahahahah ahahahaaahhahahahahahahahahahahahahaaahhahahahahah ahahahahahahahaa

[growler2058]

ahhahahahahahahahahahahahahaaahhahahahahahahahahah ahahahaaahhahahahahahahahahahahahahaaahhahahahahah ahahahahahahahaa

:cheers::cheers::cheers::bananadancing::1062::beer : CHEERS MATE

[katwoman]

Hasent been looked at yet.. I might have a go myself. The black lead goes to the + side, yes ?? PML.

[growler2058]

Why are you awake?????????????????

I know your hearing the call of the mighty GQ and cant keep away ay

[nowoolies]

im suprised the box of matches has`nt come into play yet hahahahahaah

[katwoman]

Coil wires look 'normal'. Kero-soaked rag is ready to go !!

[growler2058]

BUMP hahha
Ive got it!!!!.....................Try speaking nice to it instead of all the insults ahhahahahahahahahahahahahahaa

[katwoman]

BUMP hahha

HEY... I opened the bonnet and actually looked !

Oh, oh, oh..Guess what ??? off topic !!! whoops I'll go to N/S..

[Yendor]

That's a bummer.

So there is no wires that come from the LPG system and go to the coil?

Can you see where the LPG wire harness does go to?

[katwoman]

That's a bummer.

So there is no wires that come from the LPG system and go to the coil?

Can you see where the LPG wire harness does go to?

Hang on, I'll go take some pics...cos I dont really know what I'm looking at, anyway...

[NissanGQ4.2]

Not sure how your gas computer is set up,

Do you have something similar 2 this located either on the passenger side fire wall ( where the ECU is located ) or the passengers left hand side kick panel ( where the TCU is located ). If so unplug it and then try running it on petrol.

7549

[katwoman]

Not sure how your gas computer is set up,

Do you have something similar 2 this located either on the passenger side fire wall ( where the ECU is located ) or the passengers left hand side kick panel ( where the TCU is located ). If so unplug it and then try running it on petrol.

Umm, similar to what Todd ? Sorry, I'm not following..

[NissanGQ4.2]

Umm, similar to what Todd ? Sorry, I'm not following..

sorry got carried away and forgot 2 post the pick *L*

[Yendor]

Not sure how your gas computer is set up,

Do you have something similar 2 this located either on the passenger side fire wall ( where the ECU is located ) or the passengers left hand side kick panel ( where the TCU is located ). If so unplug it and then try running it on petrol.

7549

Todd, does that unit plug into the vehicle original ECU?

[katwoman]

http://i1110.photobucket.com/albums/h453/katwoman001/The%20Snotbox/023.jpg

http://i1110.photobucket.com/albums/h453/katwoman001/The%20Snotbox/022.jpg

http://i1110.photobucket.com/albums/h453/katwoman001/The%20Snotbox/021.jpg

Coil... Gas wires just go to relay on inner mudguard.

Not sure, Todd. Will check that one tomorrow..

[NissanGQ4.2]

Todd, does that unit plug into the vehicle original ECU?

As far as I'm aware it does, not my car 2 be ripping things out but I just had a quick look 2 take the photo and it looks like the wires run 2 the ecu, but not 100%, and it is the original ECU

[katwoman]

As far as I'm aware it does, not my car 2 be ripping things out but I just had a quick look 2 take the photo and it looks like the wires run 2 the ecu, but not 100%, and it is the original ECU

If that is part of the ECU then, snotbox doesnt have one.

[Yendor]

Thanks Todd,

Kat it should have one, either mounted under the bonnet or the same place as Todds.

[katwoman]

Thanks Todd,

Kat it should have one, either mounted under the bonnet or the same place as Todds.

Ok. Tomorrows job.. Find this box and unplug it...

[NissanGQ4.2]

If that is part of the ECU then, snotbox doesnt have one.

It's not part of the ECU as such, its just a computer for the gas system, as Rodney just posted it should have something similar 2 my pic, and yes could also be located under the bonnet somewhere.

[Yendor]

Ok. Tomorrows job.. Find this box and unplug it...

Unplugging it may stop the injectors from working, this is ok, at the moment we are trying to get spark when on petrol.

If it doesn't start on petrol with it unplugged you will need to at least check if it has spark.

What did you do to get the fuel pump to work?

I keep thinking back to Silvers post, "I used to set it to supply both as an anti theft measure" and wonder if someone has wired this up so when it was switched to petrol it worked as a kill switch????

[YNOT]

I would forget about the 'replacement ECU', if you plug it in and you loose spark, it's dead.
Your original ECU may be faulty but the ignition side is at least working. Do you have spark with the original ECU when you switch to petrol and did your auto sparky check for injector pulse?

When you say the fuel pump is fine what fuel pressure are you getting? The pump may appear ok pumping fuel out of an open fuel hose but may not be producing sufficient pressure when connected and under load.

If the car has been run exclusively on LPG for an extended period the injectors and fuel filter will most likely be gummed up. The fuel pressure regulator may have suffered as well.
I would also be replacing the rubber fuel lines. I know of a heap of dual fuel cars that have gone up in smoke due to deteriorated/perished fuel lines that have split and started a fire.

The Lambda control unit someone (Todd I think) mentioned is unlikley to be the cause in my opinion, happy to be proven wrong though. This is only a mixture trimming device that looks at the exhaust gas oxygen sensor, used to make the gas system comply with emmissions regulations.
A more likely culprit is the change over switch and related components that are used to cut power to the injectors while you are running on gas. The injector side may have been left disconnected as the previous owner had no interest in running on petrol.
I think it is unlikely they have wired it to "dual fuel" as a kill switch as this would cause the motor to flood and make it extremely difficult to start even when you do switch it back to LPG.

Tony

[NissanGQ4.2]

I would forget about the 'replacement ECU'.....

yeh that's exactly what I've been trying 2 tell Kat *L* thank u Tony for decoding my ramblings, at least somebody understands me *LMAO*

[katwoman]

Thanks guys. But I think it is getting beyond me. I was looking around under there today and there's bare wires and relays just hanging in the breeze. I'll pass on all this info to someone who cares. It's not something to tackle when you are at the height of nicotine withdrawal. I'll let you know what the problem is, when and if someone else fixes it.

[NissanGQ4.2]

cmon Kat give it a go, its nothing ur skills can't fix, forget the fags.......quad triple bourbon will help you get ur head around it :)

[katwoman]

Bourbon burns better than kero ?? I'm out of time, Todd. Going bush 4 w/end, back to place of employ Monday !

[NissanGQ4.2]

Bourbon burns better than kero ?? I'm out of time, Todd. Going bush 4 w/end, back to place of employ Monday !

hang on sec, will go see...................BANG!!!!! nah kero burns better.............but i will drink either :):):) Enjoy ur weekend away, always good 2 get away before returning 2 W.

Will be interesting 2 find out the outcome