Today my Z suddenly started missing really bad and gradually lost power over a couple of minutes backfired a lot and stalled.

The car would not start again and just cranked and spluttered. Left it for 5 mins and it fired up again. 2 minutes later it did the same thing again and has been the same all the way home this afternoon.

I pushed the PTU and coil connectors in but no difference - just seems to need a 5 minute break!

Any ideas?

It's almost definately your fuel pump mate, I had the same problem, and it drove me nuts for weeks until I replaced the fuel pump.

Hope this helps,

Brian

Where is the fuel pump hidden?

I've never replaced the fuel filter so i'll try that too but unless it's suddenly clogged it seems doubtfull.

How much are the pump and filter?

Any other theories chappies?

 

Is that not the symptom of the PTU overheating, been reading some posts and they were say that the car cuts out and once the unit has cooled down it runs again until it overheats and packups again. Might be worth doing a search??

 

Hope this helps Mark

Is that not the symptom of the PTU overheating, been reading some posts and they were say that the car cuts out and once the unit has cooled down it runs again until it overheats and packups again. Might be worth doing a search??

 

Hope this helps Mark

It could be either (or neither) but PTU failure is sometimes indicated by the cat warning lights coming on as the unburnt fuel gets chucked down there and then ignites inside them.

 

The fuel pump is an immersion type so it is located in the fuel tank, running the car on low fuel will harm it in the long run and can cause eventual failure.

I was low on fuel this afternoon but the warning light hadn't come on yet...

I presume that the backfiring is caused by unburnt fuel getting into the exhaust system so does that point to no sparks?

It just suddenly starts badly missing and becomes undriveable in a few seconds and stalls. If the PTU is going does it stop all sparks or miss on different cylinders?

I think the Crank Angle Sensor tells it which plug to fire, am I right?

 

The PTU can fail in a number of ways, depending on what the fault is..

One or any number of cylinders could stop firing altogether, or start only working intermittantly..

 

the CAS tells the engine what position the cams are at, so it controls spark and fuel injector timing (your RPM signal also comes from there)