Hello everybody,

My LR2 is giving me a hard time starting when the car is warm .
Any common issues to troubleshoot ?
note no engine fault codes found .

Thank you

 

I assume it's properly maintained, spark plugs aren't worn out, etc? Checked for loose intake, hoses, etc?

Clean MAF sensor (carefully).

Check fuel pressure. You should be able to read it with a vehicle-specific OBDII scantool such as an Autel AP-200, maybe a generic scantool.

If you want to just try the parts cannon, replace the fuel pressure sender on the end of the fuel rail. That's cheap and easy to do yourself and they pretty much all go bad on these cars.

MAF and fuel pressure sender might create a problem without a code because if they send bad data to the ECU, the ECU might not realize it's bad data.

 

actually I bought this car used recently, did not change or inspect the spark plugs yet coz I had bigger issues with the car that I was fixing gradually , having done that now I have time for this intermittent fault , I will replace the spark plugs soon coz obviously the previous owner did not do the basic maintenance probably.
I don't think there is a vacuum leak , I checked the fuel trims and mixture is not lean at all .

However when the fault occurred today i disconnected the air intake hose from the air cleaner box , it started poorly.
Reconnected hose and everything was fine again , makes me suspect air filter or MAF , I also noticed that the air intake hose to air cleaner box clamp was missing.
here are some live data attached from my scan tool .
At this point car was hot and fault active .

 

What fault codes were you getting?

 

Nothing , that's the issue , an intermittent fault without a code . I hate this kind of faults .

 

So i went to replace the air filter today and the missing intake hose clamp , i installed the parts infront of the shop , and again i was uable to start the car .
i disconnected the air hose from the cleaner box and it started poorly, reconnected hose and it was fine again .
i was convinced its an air intake issue.
Got my self a MAF cleaner , while removing the MAF i noticed that the screws were very loose, the MAF was beyond dirty it was a disaster, cleaned it properly and took the car for a long test drive , shut it down while hot , started again normally.
the air flow and air temperature reading on the scan tool went down to more than half on the scan tool after cleaning the MAF . Also the fuel mixture was 10% richer than normal , now its only 5% .
ill declare it fixed for now .

 

Good news, but that is a workaround, not a fix. Personally, I would replace the MAF sensor for a new one, since they are relatively inexpensive. Your mileage may vary.

 

Where I live the dust is really an issue, and the previous owner never replaced the air filter which caused the dust build up on the sensor, the readings of the sensor are all normal now , ill keep an eye on it if it causes any more problems ill replace it .
👍👍

 

Problem came back , cleaning the sensor helped the car performance a lot but the starting problem is still here , not sure if the MAF is related anymore .
what are the most common reasons on this car ?

 

Look at the other messages. As I said, put a new MAF sensor in there first. Then look for other possible causes if the problem is still there.