Hi chaps

I have MY7 S/C all has been great with my car since I have had it for the last 5 months. Except an alarm issues , which was fixed with some great advice from member on here.

But just recently I found that I cannot boot the throttle to over take when on petrol.
On gas it works fine ,on petrol it losses power when I accelerate hard @ 3500 rev upwards.

I got a engine management light come on & off every so often when this happens. As regards fuel on board it's happend full & half full & 1/4 full .

Any ideas chaps ?

Regards
Ray

Have you got access to an OBD code reader? If you are getting the MIL (Engine Management) warning light coming on and going off, there are events happening which are then clearing (i.e intermittent). First step would be to see if you have any 'pending' codes in the ECU - this could give you a clue as to where to start looking.

My FF is a 56 plate normally aspirated AJV8 4.4, with LPG conversion, and when I got her in January I had an issue with the MIL coming on and a 'P0170 fuel trim bank 1' fault code.

After some research, turned out to be that i needed a later ECU map. The technical bulletin about this contained a range of VIN nos. going through to 2007 and including 4.2 SC models. This may not be relevant, but if you could see what (if any) fault codes you are getting, it may offer a pointer.

Could be that you have an injector issue, or problems with the petrol mapping?

If you need further info on this, I have posted more detail, you should find the post by searching on 'p0170'

Best of luck.

Another Ray  2006 (56 Reg) 4.4 V8 Vogue In Bonatti Grey (Gorgeous!!)

Ours recently had reduced engine performance warning light which turned out to be a new SC water pump required.

Another thing to try is update the ECU software, i.e. loading it with the latest version of software. It solved my MIL issues on the 4.2

I also suggest to do some more driving on petrol to ensure that the fuel is not gunking up (silicon deposits) and blocking the system. Maybe get your petrol filter cleaned/changed. (bit of a job as it is pump mounted inside the tank) as well as it may be clogged up already. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

As above, I'd say it would be injector/fuel filter related. The LPG system obviously doesn't share that bit.

I had the incorrectly wired S/C aux coolant pump too. I wonder if this split fuelling also means that the mechanism used to 'cut' the power when on petrol can't cut it on gas so, despite the coolant pump 'warning' the system, the gas carries on supplying merrily?

Definitely get the codes read.

Good luck- hope it's cheap/easy!

Hi all

I have had the fault code read and it is P0088 Fue Rail/System Pressure - Too High

Any ideas ?

Regards

Ray

High again

I found this on the net as well which I think answers the question .
Unless anyone has any other ideas ?

Models
LM - New Range Rover
LS - Range Rover Sport

Title AJv8 Supercharged DTC P0087 & P0088 Fuel Rail Pressure
Last Modified 27-OCT-2008 09:45
Category Engine
Symptom 404000 Fuel System Concerns
Content
Issue:
AJv8 Supercharged Engine DTC P0087 & 88 Set in PCM (Fuel Rail System Pressure Too Low / High
Cause:
Pressure sensor Part Number 4458309 has been reading erratically and setting the DTC
Action:
Note:- The sensors have now been modified and stock has been purged. A green dot was applied to the first 100 sensors only to confirm this action.
The sensor has been introduced from engine build date 22/04/08

The date is part of the engine number as follows.

XXX X X 220408 X XXXXX

Hi all

Well what I say . I ran the car on petrol for 150mile + and the issues has seemed had cleared itself ????

Does anyone have any ideas . As I am totally lost.
The only things I can think is, it is something to do with the ecu . As the gas and petrol run though the same thing . Or running on gas is affecting the petrol injectors .

I have a prins system and only done 7k so far

Could have been a simple case of fuel gunking up. When petrol sits for a long time it can start to form some deposits that reduce flow, hamper valves from working properly. That is why it is better to drive on petrol every quarter or so for a 100 miles odd. Just to keep the petrol system working fine.

No sure how sensitive modern fuels are to this phenomenon but that could be it. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

I don't understand why the injectors get affected . As the car starts on petrol every morning then changes to gas once warm.

But at the end of the day a good run on petrol seems to have fixed it :-0

Also petrol goes stale over time, i.e. the more volatile components evaporate and some of the additives can get separated. The problem may just have been bad quality petrol, gunking, evaporation, additive separation. Nothing to do with the injectors as all, just bad fuel not getting to the injectors in sufficient quantity.

I had my entire fuel system cleaned and a new pump installed in a petrol 4.2 SC that had been sitting still for 2 years in the tropics (Nigeria) and it solved all my fuel system problems, including irregular idling. It was a big job (they also cleaned the inlet manifold for example) not expensive though (Kingpleb found a brand new dirt cheap SC fuel pump on eBay) as labour was for free for me (company I worked for have their own car mechanics).

I was pretty happy with it afterwards.

In LPG cars (I had a few in Holland) the petrol hardly gets used apart from the start and goes stale, gunks up etc. I used to run it on petrol for 100 kms once a month at least. Never had any petrol related issues. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!