hi to all I saw that since the gas station tells me full I put 5/7 liters with the tank and I see it by removing the cap. I did 70km and began to lose shots it seems that no gas arrives when I press accelerator and feel strong vibrations, then turn off and on again everything disappears in Parrivo at 6000rpm well this situation has been happening for some time, I changed fuel filter 4 times (dirty) cleaned injectors put several additives in the tank and always keeping full sometimes tells me poor mixture bank 2 or bank 1 to LPG no fantastic car problem. what can i check in the fuel line? Does the pump have a pressure of 3.5 / 4 bar? can I see it with the diagnostics? and a year that I own xj8 4.0 12000km routes but I could not appreciate the petrol engine help me to enjoy this great car

 

I would check and clean the MAF sensor with a MAF only cleaner. Your TPS (throttle positioning sensor) could be bad? What about your air filter...a dirty air filter will cause your scenario also....check your cam cover vent line for blockage also.

 

the maf has been cleaned, new air filter Sprint Filter the TPS where is it? how do i check it? the new cam cover gasket

 

First, bookmark this site... JagRepair.com - Jaguar Repair Information Resource
This is a pdf manual from there... http://jagrepair.com/images/IntroToJ...al-10-3-02.pdf

...here's a TSB pdf from that link... http://www.jagrepair.com/images/TSB/XK8/303-58.pdf

...and here's a screenshot from that pdf and I circled the TPS for you, this is from section 1.3:

 

Can the TPS be viewed / checked with the diagnosis?

 

Does TPS exist as a spare part?

 

From the link... JagRepair.com - Jaguar Repair Information Resource

This is a thread a member took some time to help evaluate the TPS... https://www.jaguarforums.com/forum/x...1-info-172815/

 

thanks for the info a question: LPG is the only good thing and it takes more time to turn on, especially when everything else is ok. if it were the TPS would it also give me a problem with LPG?

 

I understand that you have a dual fuel system - Petrol and LPG. I also understand that your car runs well on LPG and poorly on Petrol. If this is correct, I wouldn't look for a problem in the TPS or elsewhere but in the fuel change-over system that has been added to the car. Otherwise, the fuel pressure should be around 3 Bar. There is a Schrader valve for checking the fuel pressure; it is located at the front of the left fuel rail, usually covered with a blue plastic screw-on cap. The valve is of the same type and size as a tyre valve and you will need to use a suitable screw-on connector with a hose connected to a pressure gauge. You may be able to use a tyre pressure gauge but only if it has a brass screw-on connector for the tyre valve. Something like this:

 

Thanks for clarifying MS, I was out there on the LPG and didn't know they ran that.

The TPS monitors the amount of rotation of throttle being applied to help determine air/fuel mixture. Thus each TPS is calibrated for each vehicles requirements to function. The electrical pulse is sent to the ECU where in combination of the MAF and O2 sensors, it helps determine the air/fuel ratio. So if its out of adjustment or malfunctioning, you most likely with get the wrong air/fuel and situations like poor response, stuttering, stalling and/or hesitation. The same goes for a failing MAF and O2 sensor.

The one link tells of bad pinning, not the sensor, that was an issue on many of the X308 Jags.

 

So should I do the petrol carburetion in the Jaguar workshop? or is there an alternative?

 

You did not confirm that you have an LPG system installed in your car. If yes, I would first go the an LPG installation specialist.

 

BRC Italian LPG plant that I have had overhauled: injectors, filters, reducer, tank and multivalve replaced by the official installer. then he made me the carburetion and he noticed a difference in the start-up phase, especially with LPG hot, more time is needed. note that xj8 always starts with petrol then automatically switches to LPG based on the temperature

 

Food for thought.
Isn't it that LPG is a problem for the valve guides lubrication as its a dry fuel
because when I had an LPG system it was 3 tanks of LPG then 1 of octane to keep the valves, ok
some people added an automatic lubrication system.
also, the way an engine is set up to mix the liquid from the LPG tank to gas by preheating it in a heat exchanger that uses the heater hoses on the car and then it is regulated.
I don't know what the MAF and other sensors would do or react to that. remember this is an older car designed for Petrol.

 

hi to all even today after 60km turns on engine light and limited performance, says too poor mixture bank 1 and bank 2. xj8 was fine no rips (I went slowly on the plain) a doubt 14300km probes lambda to change, in the sense that give a wrong value, can it happen? all this only on petrol