v6 misfire argh!

[customx89]

I have a vx that seems to be misfiring when hot and under load, but only at low rpm. It happens most noticably uphill when it is around 2000rpm, or when i put my foot down to overtake after crusing for a while. Its shocking with a.c on. I have spent hours reading through forums and notice that this seems to be a common problem. Mechanic replaced plugs, leads and one coil about 5 mths ago and went away. But after, the car seemed harder to start. New battery too.

I tested the coil spark by removing leads of coils and checking spark runs prong to prong and they seem ok. Also tested lead resistance, range from around 1.2 - 5.2 kohms. Is this ok?

It seems others have had similar problems with DFI, coils, CAS, fuel pump..

Can anyone help me out with any advice they can offer on testing to check if its any of these problems or possible solutions..this is driving me insane.

Being slow to start makes me think it could be more of a fuel issue but have no idea how to test.

[vt s]

Knew someone with similar problem spent bout 1200 replacing stuff to find out it was cam angle sensor which was worth $60

[pixiemops]

I have a similar problem with VX backfiring on gas . Seems to only happen when starting off ie accelerating from a stop and when the engine is warmed up . Plugs new leads and coils have all been replaced . Wondering if it is worth changind the Cam angle sensor.

cheers

[Northern_Union]

My old Subaru would do that as well. Turner out to be a $40 termostate....spend $1200 minimum looking for it.

[Tree cutter]

It could be another coil on the way out. They usually only start to break down when hot and get better once cooled down. They usually get worse with time and pack it in completely

[customx89]

yeah not too keen on spending big bucks fixing it when its probably something small. It is very similar to when the old coil needed replacing...maybe i'll start with the coils. its playin up more now the temp is getting hotter. Is there a way to check cam angle sensor? How do you replace it

[Sheany]

Check your plug gap. Found that was making mine miss something chronic. I believe it should be somewhere around 1.3mm for an ecotec, someone correct me if I'm wrong

[nathanVY]

anyone know what the gap is meant to be for a V6 VR, buick?