Thread: TD5 mis-firing and surging (i think)

Give the MAF a clean with maf cleaner dont touch it, had that happen to mine and it sorted it out

MAP sensor also while u have the cleaner out anyway

Originally Posted by lyonsy

Give the MAF a clean with maf cleaner dont touch it, had that happen to mine and it sorted it out

Can also just disconnect it for a quick test to rule it in or out if you are too lazy to take it out.

Definitely clean the MAP, can't recall the difference between defender and disco with the turbo but if it's only under certain circumstances it is likely the air to fuel ratio causing issues.

Without a nanocom you can check the TPS with a multimeter, it's a 5V system so you can check linear change through the stroke. My guess is it isn't the TPS though, it wouldn't give you a 'miss' I don't think.

It's boost or fuel related, mine used to do this with a slightly rough idle when the wastegate rod was stuck open (so couldn't build boost).

Did you do injector washers when you did harness?

Originally Posted by lyonsy

Give the MAF a clean with maf cleaner dont touch it, had that happen to mine and it sorted it out

Thanks, I will research into whats involved … is it worth replacing it, or just a clean ?

Originally Posted by RobMichelle

Did you do injector washers when you did harness?

No, thought about doing it, but don't think it needs it at this stage, and as this is the first mechanically works I have done on a land rover in nearly 20 years, I thought I would start with something small first and build up from there …

most of my other vehicles have been station wagons or work trucks … this is my first weekend toy and so far i'm loving getting back on the tools again … wife still asks if we bought a lemon … I reply "Nah … its just another Landy thing"

thanks for the quick responses guys, I will try disconnecting the MAF sensor and go for a run to see what that does … now all I need is the RTFM and figure out where to disconnect it

Also be sus on the FPR, as well as the injector washers.
Any leaking around the FPR?
The other notorious part to keep in mind is the fuel pump. Could be failing.

So your surging is both under no load AND under load? or is is just with no load?

MAF plug is the really obvious one on the MAF; passengers side back from the air box on the MAF body.
There is another plug on the airbox close to the MAF, smaller plug, this is the ambient air temp(AAT) sensor.

It's an early D2 so it's likely got a 10P engine. If that's the case then I believe that the MAF is only used to run the EGR and doesn't have an effect on fuelling. I could well be wrong of course. If it's a later engine then the MAF IS used by the fuelling algorithm.
My guess is that it's something to do with the fuelling - pump, FPR, air getting into the system, etc.

Clean MAF Sensor
explains the MAF cleaning nicely