My Z has deteriorated overnight. To follow on from my previous thread - basically from the start of this week she's been driving like sometimes she's on 5 cylinders. Once the engine warms up, she misfires a little and holds back a bit when I accelerate from low revs. She boosts ok, although now sometimes she'll judder a bit as the revs go above 4k. Don't appear to be symptoms of wet MAF as I've had that loads of times before (revs just cut under boost).

 

Anyways yesterday afternoon on the way back from work she started to buzz loudly whenever I took my foot off the throttle. The sound seemed to be coming from behind the dash, but I confirmed this morning that it's from the driver footwell.

 

I went out today with the hope of fixing the misfiring - I taped up a couple of cut/bare wires, pushed the coilpack plugs in firmly, checked the ECU temp sensor, the plug to the CAS and TPS, and had a general nose around the engine bay. I also taped up the connections to the PTU (which is relocated and exposed a little to the rain under my nose panel) and fired her up.

 

She idled ok for a couple of minutes, then as she warmed up the revs dropped to 650 and she started to struggle idling. She revs ok (but hesitates a bit), but if I rev her over 4k or so, once I take my foot off it'll drop and stall. No visible smoke from exhausts, although yesterday there would be a puff of dark grey smoke on overrun.

 

The LIGHTS warning light has started to come on which it never has before, and when I rev the engine, or switch the fans on, then off, there's a loud buzzing from the driver's footwell, around the fusebox area - like a failing solenoid perhaps. From cold, the LIGHTS light would flicker quickly 'in time' with the buzzing, but then it stays on.

 

Video is here:

 

Any ideas as I wonder if these symptoms are connected somehow...?

Noooo don't do it. I am sure you will track down the gremlins soon.

Once you have, you will enjoy the full joy of your zed once again.

FIXED!

=====

 

A certain Mr. J. Turner at a certain Z specialist in the Midlands area identified two issues that were causing the electrical problems - one of which was a faulty diode tucked away in the engine loom somewhere [the existence of which you wouldn't know without looking at a wiring diagram], and the other was a faulty [as in partly broken possibly due to a pothole] fuse in the engine bay.

 

Jeff's explained it to me twice and the details still escape me, but after looking at a wiring diagram it appears that a current was finding its way onto both sides of this particular buzzing relay causing the switch to flick back and forth and therefore buzz. I think the circuit was to do with the rear lights, but perhaps Jeff might want to post a bit more detail [i.e. tell me a third time!]. So a big thankyou to Jeff for quickly getting to the bottom of this and fixing it. Apparently the faulty diode could have been contributing slightly to my parasitic drain, and so I'm currently measuring that on a daily basis (without using the car) to see if the car can list a bit longer without dying. I've just started a new thread measuring the volts each day.

Edited June 2, 201313 yr by EvoluZion3

Good to hear you got it sorted.

 

Nice one Jeff.

Great news mate :clap: what would we do without Jeff.

Great news mate :clap: what would we do without Jeff.

 

Amen brother.....

 

Richard:helpsmilie: