VX Dual Fuel (Aftermarket) DTC57 Injector Monitor Line problems

[V6formethx]

Hi all, and thanks in advance if you are even reading this, let alone able to offer assistance.

I have never come across and issue with these motors I haven't resolved myself, but this has me absolutely stumped after months of trying to figure it out.

Issue:
Engine light comes on after a short time driving every-time the car is used. Plugging in with Tunerpro RT and ALDL cable I can see that DTC57 is being triggered, the software says this is "Injector Monitor Line Fault". This happens regardless of whether the car is on LPG or Petrol.

Symptoms:
* Car seems to hesitate or stumble at time the light is triggered.
* Car runs roughly on LPG and will eventually stall and or backfire.
* Does not stall on petrol although a feeling like it is not running very smoothly is noticeable.
* Noticeable increase in fuel consumption.

History:
The car has always tripped this code every so often but has always gone away after not very long without even needing to restart the car. I was told this was normal due to the LPG system and it has never produced any side effects to cause me to think otherwise.

It started after the following work was done by me to the car:
* Replaced injector seals that were leaking.
* Replaced PCV Valve only because they are cheap and I had already pulled the engine down to that point so I figured I'd save the potential issue in the near future.
* Replaced valley gaskets, both sides.
* Replaced all vacuum lines.
* Cleaned throttle body and intake plenum while removed.
* All new gaskets used on everything removed.
* Replaced both engine mounts.
* Oil filter and oil change.
* New spark plugs and 8mm quality leads.

What I've Tried:
I really want to write "everything" here as that is what it feels like, but clearly there is one resolution I haven't tried yet, the correct one! So here goes to the best of my memory.

Switched the following with known working parts:
* Intake Air Control Valve
* Throttle Position Sensor
* Ignition control module and all coil packs
* Plugs and leads
* Both O2 sensors (individually with test drive in-between)

Have tested the wire identified as the injector monitor line by the service manual from end to end with no sign of altering resistance throughout car. It shows battery level voltage. I've checked all electrical connections figuring I may have knocked something that had a dicky connection already, put new connectors on multiple wires related to the LPG as a result, but the issue remains.

Have ruled out an injector being damaged as the issue occurs on LPG still and it is actually only able to be driven on petrol.

Have thoroughly checked for vacuum leaks everywhere but behind dash as the heater and vent controls operate fine so I ruled out any fault on the cabin side of the firewall.

There is probably more that I'm not thinking of right this second but I will add this if need.

Any help greatly appreciated, I fear this is literally starting to drive me insane! I have been over and over anything I touched and cant fault my work, yet it only started after doing that work and is basically telling me it has to be related, or the worlds biggest, and cruelest coincidence. No suggestion or question is considered a bad one, this is desperation at this point.

 

[Lex]

Lpg filter?
Whats your spark plug gap?

 

[V6formethx]

Lpg filter?
Whats your spark plug gap?

I forget exactly but I can tell you they were checked against the service manual specs and the new ones were correctly set already. I then made them .2 smaller gap for the LPG. I had the issue before changing plugs but after the other work, which is a finer detail I had not mentioned. I have heard different things in regards to where to set the gap with LPG installed if you had any input? I believe it can make a reasonable difference.

 

[Lex]

I think l remember reading on this forum, that different members had good out comes with 0.8 mm - 1.3 mm?
I think also a few had good results with 1.1 mm?
Another member changed the lpg filter with good results.
I have noticed that you have not mentioned anything about a filter.
The .08 mm may have been a lpg only system?

 

[delcowizzid]

Dtc57 will be turned off in a vx lpg bin maybe go see a tuner and get them to flash In an lpg tune.

 

[BlackVXGTS]

The attached excerpt from the VT/VX Service Manual may help you:

 

[V6formethx]

I think l remember reading on this forum, that different members had good out comes with 0.8 mm - 1.3 mm?
I think also a few had good results with 1.1 mm?
Another member changed the lpg filter with good results.
I have noticed that you have not mentioned anything about a filter.
The .08 mm may have been a lpg only system?

If I have an interest in something, I study it until I know it inside and out. LPG I have never had an interest in so I'm blind in regards to an LPG system except understanding the electrical side of them. Bottom line..... There's an LPG filter?? The LPG was checked for the 10 year compliance about six months ago, would this have been renewed then? And will this also cause issues on petrol?

 

[delcowizzid]

Post a driving log up from tunerpro

 

[Lex]

If I have an interest in something, I study it until I know it inside and out. LPG I have never had an interest in so I'm blind in regards to an LPG system except understanding the electrical side of them. Bottom line..... There's an LPG filter?? The LPG was checked for the 10 year compliance about six months ago, would this have been renewed then? And will this also cause issues on petrol?

No idea about the filter. Another member on this forum was having problems with his gas system & would get it serviced, & no they didn't change the filter.
I imagine the gas problem wouldn't have an issue with petrol, unless there is more than the one issue.

I had another quick read of the start of your thread, sorry missed the part of about running rough on petrol too.

I suppose you have checked the injector wiring?

You could try posting a log of tuner pro as delcowizzid suggested.

Good luck with sorting it?

 

[V6formethx]

I actually recorded two short drives yesterday with the plan to upload them, will do that soon. Yes, tested injector wiring and the injectors themselves, cant fault them. Problem is though it will idle all day long and not trip the code, but driving it does without fail. Can't work out a pattern with when it trips either. Not timed with bumps, acceleration or anything I can pick, seems random, but certain.