Hi,

I've just converted my 4.2 35000 miles to lpg and today the check engine light has going on and message "restricted performance" appears with impossibility to have more than 2800RPM, after it stops...

What could be the problem please?

Thanks.

Best regards
Chris

 

If the MIL is on, it may be helpful to post the DTCs here.

It is also helpful if you provide vehicle details such as MY, model and anything else to assist those trying to help.

A message regarding 'restricted performance' may be caused by the communication between the TCM and ECM following a misfire situation. The ECM does not allow the engine to rev beyond 3000 RPM when the gearbox is in 'P' or 'N' positions.

How many kilometres/miles has the vehicle travelled since the LPG conversion?

 

Sure, it's 2003 XJ 4.2 with 35000 miles.

LPG conversion has just 200 miles ago!

Check engine on this afternoon, before all was ok and no probelm of power, it was going perfectly instead on petrol or gas...

Your information is very interesting because the check engine light has going on when I was on P position, I was just washing my car 2 minutes at washing station (engine was again on) and it was when I redrive the car that I saw that the check engine light was on!

Do you think this message would disappear if I restart my car on petrol?

Have you a scheme of TCM and ECM please?

 

The MIL is not associated with the position of the gearbox lever. What DTCs are stored in the system if the MIL is on?

Perform a search of the X308 forum for information specific to your situation. There are also 'sticky' threads on the forum that you may find helpful. Use JTIS Workshop Manual and schematics for diagnosis. Both are free to download from this website, or you can purchase a .pdf file of the Workshop Manual over the Internet on sites such as eBay.

 

Chris,

I've moved your question from General Tech Help to X350 forum. This is the place to post tech questions about your model.

Graham

 

It's a 2003 X350.

Here is a picture.



Tonight when I start it was always written "restricted performance" but it disappear after 100m but check engin is always on.

I've tried to go more than 3000RPM, it's ok.

So I think you're right, the problem occures when I was on LPG and in P position, if I stay on Drive in traffic jam there is no problem...

Would it be a problem of exhaust oxygen sensor?

 

Read the codes.

 

Definitely. If the light is on, there are codes stored. Without reading them, we are just guessing. Any Autozone, NAPA or oReilly's will let you use their reader for free.

 

Do you advice me MAXISCAN 309?

OBD OBD2 EOBD KW806 Canbus Pro ENGINE FAULT CODE SCANNER HYUNDAI VAUXHALL JAGUAR | eBay

 

Hi I have had LPG on a few Jags (S-type v8 and x308 v8 3.2) and have just removed it from latest Jag x350 XJ6 2003 due to multiple misfires and RP message.
I removed so that I could troubleshoot on petrol and may reinstall.

Does your install have a petrol return line? this can upset running when back on petrol? The pump learns to run slowly due to little fuel use while on LPG.

You need to get codes read and start from ther: but if it doesnt run well on petrol it will never work correctly on LPG?

 

Check engine light disappear this morning when I start it and never reappears today, I'm very happy!

So I can't give you the fault code.

To have an idea it gives me actually 12 liters/100km on lpg so it's very good.

The car works perfectly both in petrol and gas, the problem arrives when I was on P position and the engine was on lpg, I was just washing the car 3 minutes and the check engine light appears.

I have no idea of what was the problem.

Best regards
Chris

 

Glad its working well just keep an eye on it as its a new install

 

Codes stay stored for a LONG time (40 or so drive cycles) so you can still read them.

 

I've bought Maxiscan MS309 and it's very easy to use.

Fault code is P0174 "system too lean bank 2"
and "P1111 manufacturer control"


What do U think about it please?

 

Look them up in free download workshop manual and also use Search on here. Worry a lot about P0174.

 

Hi cristophe_autos,

You can download the X350 Workshop Manual from this forum in six sections at the links below:

http://www.mediafire.com/download/md...f+contents.pdf
http://www.mediafire.com/download/aa...nformation.pdf
http://www.mediafire.com/download/n3...2.+Chassis.pdf
http://www.mediafire.com/download/9b...Powertrain.pdf
http://www.mediafire.com/download/0i...Electrical.pdf
http://www.mediafire.com/download/4j...+and+Paint.pdf

You will find the definitions of Diagnostic Trouble Codes (DTCs) that begin with "P" in the Powertrain section of the manual.

Note that the MaxiScan MS309 appears to be a standard generic OBDII / CAN scanner and will probably not be able to read the proprietary Jaguar codes, which are "B" (Body), "C" (Chassis) and "U" (Undefined, mostly network-related) codes.

As JagV8 mentioned, you'll want to find and correct the cause of your P0174 code. In my experience the most common cause has been an air leak in the intake air plumbing somewhere between the MAF sensor and the intake manifold gasket, but the MAF sensor itself can be the cause, as well as several other issues outlined in the manual.

Please keep us informed.

Cheers,

Don

 

Thank you so much for this links!

Cheers,
Chris

 

Is the code when running on petrol or gas/LPG?

 

The new gas install could be leaking vacuum due to having bits screwed into the manifold?
But if the code is only while on gas its a setup issue and needs the Gas map tweaked.

 

MIL disappear spontaneously after 4 starts and never reappears...