Mpg is down to around 20 on urban driving and the car has slight misfires but normal enough to drive without issue. Misfire went from Injector 3 to 4 after changing injector 3. Injector deviation readings are also very weird. Can't seem to figure out exactly what's wrong as all 4 injectors seem to be off? 

Injector wiring harness? not experienced it myself but they can give strange misfire issues when they start to fail.

Check the torsion value. Needs to be zero.

Checked and it was on exactly 0

Injector wiring harness is definitely a thought as all 4 injectors can't be this off whilst still being driveable surely. When I changed the misfiring one it made no difference at all besides moving the misfire. So wiring could definitely be a cause. How much is the labour for the wiring harness to be replaced? 

45 minutes ago, DiazFabia said:

Injector wiring harness is definitely a thought as all 4 injectors can't be this off whilst still being driveable surely. When I changed the misfiring one it made no difference at all besides moving the misfire. So wiring could definitely be a cause. How much is the labour for the wiring harness to be replaced? 

 

I have no idea what the labour rate is round your way, it's about an hours work plus the cost of the loom.

3 hours ago, sepulchrave said:

Check the torsion value. Needs to be zero.

A true zero and not a false zero through being outside of limits.

 

I dont know about that engine but on the PD diesel you had to be absolutely obsessive and have the touch of a surgeon and the patience of a saint to actually achieve a true zero reading, in fact you have to be very adept just to get it within the measured range.

 

When anyone tells me their Torsion Value is zero I suggest they check it is a true reading by looking for a variation when the engine is revved, it should go negative (retarded) but I think as usual VCDS has it backwards, all that is important is that it changes by a small amount, if it doesn't then it will be a false zero.

Was the cambelt changed or any other work done before the MPG dropped?

Camshaft was changed recently but its been the same as before just less knocking 😂 mpg isn't any different. So doubt it's related. Haven't changed the cambelt but assuming it's adjusted fine. 

I'll be sure to check if it's not right on vcds asap

Got my own vcds lite and scanned the car. It came up with these fault codes.

Also the Injector figures aren't as bad, but injector 1 and 4 are still way out.

Torsion is at about - 1.7 so I guess that's not causing the problems. 

Torsion angle should be 0.0, not -1.7, it will not run as well as it could until adjusted.

 

http://wiki.ross-tech.com/wiki/index.php/16485/P0101/000257

 

http://wiki.ross-tech.com/wiki/index.php/17964/P1556/005462

 

http://wiki.ross-tech.com/wiki/index.php/18027/P1619/005657

 

http://wiki.ross-tech.com/wiki/index.php/19561/P3105/012549

 

 

I understand that but I still doubt it's causing these specific issues since its been happening since before camshaft change and cambelt adjustment. PDs are usually fine as long as they within tolerance. 

 

Gonna get onto checking vacuum lines, MAF and wiring because of the other fault codes. 

Just disconnect the MAF, if it runs better then replace it.

 

I would say you probably have a vacuum leak since you have two codes showing that depend on good vacuum.

 

Glowplug relay comes a distant third in importance.

Does that test work on BLT engines? I heard removing the MAF only affects the ASZ models. But I'm definitely seeing if there is a vacuum leak since most signs point that way. 

 

Would vacuum issues cause injector problems too or would that be a whole separate problem? 

 

Glow plug relay has been there messing about intermittently so that's not a major concern right now 😂

Alright so fixed the Injector readings. All within spec now by changing the 3 Injectors that were faulty. Smoother at idle but still starts up funny with it hunting for revs (requires me holding the key over longer until it catches 900rpm) and still has mpg issues. The mpg is still half what it should be. So clueless rn. Got a tiny boost leak but I'll be replacing that one pipe soon and the fmic shouldn't have any leaks at all. Had vacuum leak tested and shows no leak. Going to do a service and hopefully that does something but I'm doubtful.