Z22SE - P0340 Camshaft Sensor, done the obvious!

ohawker

Hi all,

So, I have P0340 flagging up:

Z22SE, ₉₇₀₀₀ miles, Astra G Convertible
EML is intermittent.
Air temp sensor reads 25 degrees in 2 degree winter- old one is on the way but find it hard to imagine it could be this causing the fault. New one in the post.

I have already...

Changed coil back (last one died!)
New plugs, oil and fuel filter.
Changed throttle body (cleaned). Old one had some play leading to slightly dodgy idle and pulling away.
Removed cat since timing was not always erratic... it was completely blocked.
Cleaned EGR valve.
Pipercross air filter

Other observations:

Timing chain is in good visual condition, no noticeable loss of power or noises.
Timing seems stable on scanner.
Engine start is a bit rough 50% of the time. Fine once on and settled.
When (and only when) EML light is on, I get a slight under-rev every 10 seconds (exactly), almost like it's trying to resync.

(... and I know I don't have a camshaft sensor 😉 )

What on earth else can I try??

First post 🙂 Thanks!

KevinH

Hi and welcome to the site. 🙂
Did you replace the coil pack with an original one made by Delphi? Aftermarket coil packs are renowned for being problematic.

ohawker

Hi! Thanks 🙂

Nope, it's a Haas coil pack. Not entirely unheard of but not quite Delphi!

Johnss

I think z22se doesn't have camshaft sensor at all.

KevinH

Genuine GM Z22SE (part # 12580537) coil packs are manufactured by Delphi.
The problem with aftermarket and cheaper pattern units is they don't incorporate the correct CSI (compression sense ignition) sensor which negates the need for a separate camshaft sensor. 🙂

ohawker

KevinH said:
Genuine GM Z22SE (part # 12580537) coil packs are manufactured by Delphi.
The problem with aftermarket and cheaper pattern units is they don't incorporate the correct CSI (compression sense ignition) sensor which negates the need for a separate camshaft sensor. 🙂

That makes sense! I wish I could get hold of a Delphi pack just to try this... I haven't had the other coil pack for very long, likely I'd be able to return it under the reasoning that it wasn't a suitable part if it doesn't incorporate the correct sensor? :confused: I'd be happy to pay the difference for the Delphi one, but I'd rather not have to buy two!

If it is that, does that suggest that the car won't be running properly under the existing coil pack? It seems OK to me but I have nothing to reference it against; it's a bit clunky to start and seems to struggle to get a timing sync (rev dip every 10 seconds)... hmm...

ohawker

I bit the bullet and bought a Delphi coil pack, and it seems to have gone away, thanks for the tip! Supplier has agreed to take the original coil pack back also 🙂

I now have p0420, but I think that might be due to a different issue. Thanks again!