What would you do next...

[PlenumBiscuit]

2011 Calais wagon with a 2013+ LFX engine in it

Drives so beautifully

But...get on the freeway and start going up inclines then grrrrrrr it starts starving for fuel or something. I guess it's a misfire...it just starts to run poorly and yep only when it's goes up hills. Go back to horizontal and it stops

So I've changed sparks plugs, coils, injectors, cleaned maf, put injector cleaner in it, put liquid molly through it, new air filter, running 98

It's still happening

What would U try next?

I'm thinking cam actuator solenoids?

Is there anyway to get to the heart of the issue? My scan tool has live data but where do U start

Or is there a way to test plugs? Such as injector plugs? Or coil plugs?

Is there a way to know if it's a misfire on all cylinders or just one?

 

[PlenumBiscuit]

And I tried another fuel pressure regulator from wreckers

 

[uglyoldfatbastard]

Told us what car you have and what engine you have put in but what ECU are you using?
If it is a 3.0 litre ECU then that would be 95% of your problem or if you are using a LLT ECU on a LFX that is another issue entirely.
Also the fuel pressure regulator is part of the fuel pump on these cars and in the fuel tank and not like earlier Commodores so what did you actually get from the wreckers?

 

[PlenumBiscuit]

Thanks muchly for reply, you're spot on yes....when I bought this car it came with the old ecu from the old motor which was an LLT...so they upgraded the ecu when they put the LFX in it. The MAF was also upgraded I believe to a vf one because it came with the old LLT maf

The fuel pressure sensor is the one on the end of the fuel rail, similar to like the vy Ecotec...I swapped one off an lfx at upullit wreckers...and actually found the car started better

If I took it too Holden's where would they start, because the fault tends to happen at high speed when going up hills

 

[PlenumBiscuit]

This one

 

[PlenumBiscuit]

Should I get the ecu part number?

 

[uglyoldfatbastard]

This one

Ahh sensor you said regulator which had me confused.
So they would have used the LFX harness to use the LFX ECU.
I would get the part number of the ECU because you never know they could have used a LFW ECU as they are identical just the code inside is different.
If you can confirm that it is a LFX ECU then it should work as per normal so I wonder what the issue is.
Does it throw any codes?
Worst comes to worst if you can't identify the ECU I can hook up to it and read it in and tell you exactly what code is inside it.

 

[PlenumBiscuit]

I've got a scanner it's the basic one but the good one... the Autel diaglink scanner that everyone recommends on here... I'll try to scan now and try to get ecu number under bonnet if visible....back in 20....

 

[uglyoldfatbastard]

I've got a scanner it's the basic one but the good one... the Autel diaglink scanner that everyone recommends on here... I'll try to scan now and try to get ecu number under bonnet if visible....back in 20....

I have the tech2win with the latest GM software and custom software as well so can do a bit more than the Autel which is a good bi-directional scanner.
The custom software can read the entire ECU code in including the eeprom so can actually identify what version of software is running on the ECU as well as retrieve security code rather than pay GM for it.

 

[PlenumBiscuit]