VZ alloytec bank 1 misfiring and running lean

[RowanVZ]

Hey guys, I recently rebuilt this engine with 280,000kms on the clock. Did a very quick/cheap job of it (This will teach me a lesson in not half-assing things).

It idles/runs very nicely until it gets up to 100+km/h, when I occasionally get misfires down bank 1 and it's reporting the fuel is too lean on that bank too. When these codes are thrown it goes into limp mode.

Here are the codes being thrown, along with a short video of the sensor data at idle. Car is VZ alloytec 4sp auto.

Video of sensor data at idle


Does any of this sensor data look dodgy? Any ideas would be greatly appreciated. I'm gonna buy a compression tester next week to see if the head is sealing. I'm not too keen on pulling the engine apart again but I can replace some sensors (O2 maybe?) if that's what it needs.

Cheers guys!

 

[Jolls]

I would be looking at the electrical side of things first as it seems to be running fine most of the time. Fuel pump not providing enough (poor earth/lacking pressure), earthing of the injector circuit etc. A good point to start is to remove and clean all of the earths so you know that you are starting with a "clean" electrical system from the point of current flow. Do the battery terminals while you are at tit and then see how it goes.

Once you have done that you really need to download the workshop service manual (search and find the link on here). Then follow the diagnostics charts - they provide a methodical step by step approach to each DTC. Make only one change at a time so you can see what is doing what and the effect it has on the system. Painful I know but perseverance is the key.

The manual is gold and readily available!

 

[RowanVZ]

I would be looking at the electrical side of things first as it seems to be running fine most of the time. Fuel pump not providing enough (poor earth/lacking pressure), earthing of the injector circuit etc. A good point to start is to remove and clean all of the earths so you know that you are starting with a "clean" electrical system from the point of current flow. Do the battery terminals while you are at tit and then see how it goes.

Once you have done that you really need to download the workshop service manual (search and find the link on here). Then follow the diagnostics charts - they provide a methodical step by step approach to each DTC. Make only one change at a time so you can see what is doing what and the effect it has on the system. Painful I know but perseverance is the key.

The manual is gold and readily available!

Cheers Jolls, I suppose I'll grab out the manual and do some electrical diagnosis this weekend!

 

[Fu Manchu]

Cheers Jolls, I suppose I'll grab out the manual and do some electrical diagnosis this weekend!

If you mean a Haynes or similar, you won’t find the info.

You need the factory manual to diagnose things. It’s only available as a digital copy. Super handy.

 

[RowanVZ]

If you mean a Haynes or similar, you won’t find the info.

You need the factory manual to diagnose things. It’s only available as a digital copy. Super handy.

Well cheers, I'll keep that in mind for future cars. I replaced the fuel filter & fixed a vacuum leak in the PCV system and it ran slightly better then I sold the car. There was definitely more to the story than that but the new owner was happy to look into it.