D40 Diesel LPG issues

[coley350]

Hi all, had my d40 for 3 years, had a LPG kit installed which puts gas before the turbo to give massive power increase, works real good, love it to bits, but small issue is when holding throttle flat for short while, (over taking cars) the power cuts out, and i have to take foot off then back on.

this car is an auto, has 3 inch exhaust from turbo housing to tip with resinators only.

its asthough it over boosts and goes to limp mode until foot is taken off then back on.

anyone else had this issue? is there a fix for it?

 

[joshman]

Going on a wild and uninformed hunch, it might be a safety cutoff to prevent too much LPG from entering the intake?

It might just be saving you engine from doing the old' Kaboom.

 

[Old.Tony]

Are there any indicator lights that come on - like the CEL (Check Engine Light) in the dash, or a light on the LPG control (if there is one)?

I wonder if the LPG level is up a little too high, increasing the combustion temp too high? You say it's an auto, it probably had a DPF at one point which means it's still got HO2 sensors in the exhaust. I wonder if the amount of LPG is affecting these sensors, triggering the ECU into backing off the fuel?

I suppose there could also be a more "normal" reason too. Perhaps the fuel pump is not quite as healthy as it used to be, and running the thing hard makes it stall after a while. It could also be a fuel rail pressure sensor that, seeing a sustained high pressure on the rail, triggers the ECU into limp mode.

How's the fuel filter - has it been changed recently?

I'd also pop the MAFS out (it sits in the rear of the air intake tube a couple of cm outside the air filter box on the pipe heading to the turbo). Spray some electrical contact cleaner inside just to freshen it up.

 

[RustyNav09]

how does our lpg kit work. im looking for one but not sure on how well it will work alongside the chipit chip. what sort of $$$ did it set you back. advantages and disadvantages?

as for your issue i would suggest the ecu may be backing it off cause of lack in HO2,

Rusty

 

[coley350]

ho2 sensor in exhaust is a possability, fuel filter is new, lpg is high, makes more power that way!
no dash lights at all, it just looses power when been flat for the floor for say 10sec, lift foot and flat again you got another 10sec. when gas is off it dosent do it.

can the ho2 sensor be pulled out of exhaust and tied up underneith without issues?

 

[Leprechaun]

Could be overboost, fit a gauge to see what numbers your getting.

 

[coley350]

24-25lb boost

 

[Rickstar]

Too much lpg is causing a smothering affect is my guess.Too rich to burn.

 

[Old.Tony]

You can't pull the HO2 sensors. The ECU is monitoring tiny fluctuations that are deliberately added to the injection cycle to see if those fluctuations are measurable by the HO2 sensor. If the ECU can't detect the fluctuations, it may trigger a full limp mode - the HO2 sensor is required to determine when diesel (as a reductant) can be squirted into the exhaust stroke for the CAT. Regardless of whether or not your CAT is present, the function of the HO2 sensor is still there and separate.

If I was rewriting the ECU code, I'd be removing the HO2S check as well as the rail pressure fluctuation code.

 

[lookskyward1]

Try a new LPG filter, cheap fix if it works.