Fuel or Electrical - Please help

[MadGalah]

G'day guru's,

Just after some help please.

I have an 03 ZD30. Driving home after work Friday, my stereo seemed to drop out quickly then come back. It didn't turn off, just like when the radio station just dies. Then on Saturday I was sitting at the lights when the engine starting revving a little higher and the vehicle was shaking as if in high wind. I gave it some throttle and it settled back down again.
Just down the road changing up from second into third and at around 2500 revs, the tacho dropped the engine kind of coughed a little violently I guess, then came right again. It done that a couple more times for the rest of the trip.

Got my mate to come for a spin and couldn't replicate the problem.
So I thought it may just have been some dirty fuel.

Sunday night I took a drive and nothing happened it was fine. However the same issue with the stereo was happening. Even flicking the indicators on caused the radio to drop out.
My park lights were flickering, but when given some revs they ran fine.

This morning, the glow lamp light came on with a strange ticking noise and neither would go away until the car started, done the same after work for the drive home. Then driving to work the issue with the revs and rough running returned, however this time it was more often and when sitting on constant revs. The tacho needle would drop around 5500 revs I guess. I didn't notice the engine light coming on or anything. Then on the way home it ran fine again. Got me stumped. Checked the battery and alternator with the multi metre and they appeared to be fine.

I have heard something about a faulty alternator sending wrong signals to the ECU confusing it and a new alternator has fixed the problem.

Is this what I'm looking at or something more sinister, or even something simpler?

Please help me.

Thanks guys

 

[Old.Tony]

With everything that's happening, I'd start looking at the ECU. Check its earth point and then unplug it and plug it back in a few times to rub the contacts clean.

 

[bods]

As above, I'd start with earths. The main earth from the battery to the body and engine block. Might also be worth checking the earths for the instrument cluster and ignition switch to make sure they are nice and tight. If they all look OK, get the battery load tested in case it is dying and causing voltage spikes from the alternator because the charge is dropping too low.


Good luck finding the problem....

 

[MadGalah]

Thanks guys. I'll have a look this arvo.

Ran fine again this morning.

Ok so I'm not the most mechanically minded person, but I do not how to check the earth etc. Although after having a look I'm not 100% sure where the earth for the ECU is. I found the ECU tho.

On a side note. I started the ute, turned the lights on high beam with the spotties on, turned the stereo on and put the hazards on. When I done that the stereo died, the digital clock was flashing and the temperature gauge was bouncing before the car stalled.

Anyone able to tell me where the earth for the ECU is please?

 

[jonney]

if the ECU case is not part of the earth to body there must be a short earth wire coming from the ecu to the body in that area.

 

[bods]

best way to check the earth is remove the bolt or nut holding it on and get a wire brush onto it to clean up where it contacts the body or chassis. then tighten the bolt or nut back up nice and tight. if you want to seal it, you can get a can of the spray they use on your battery terminals to stop corrosion and spray some of that on the outside.

have you had the battery out recently or has anyone had it out for any reason? could be as simple as a loose terminal on the battery...

the ecu should be located under the middle of the centre console, under where the radio sits. the earths should be pretty obvious around that area I would have thought...

 

[MadGalah]

Unless we get hit by TC Ita I will spend the day working on the ol girl. Do all the connections and the ecu

 

[Old.Tony]

Stay safe up there. Ita doesn't look small from the satellite view.

 

[MadGalah]

Cleaned up the earth connections. As I was undoing the negative terminal on the battery I noticed it looked a little dodge.
So I went and bough a new terminal and grabbed a new battery while I was there.
Got home and connected it all. All the issues seem to be fixed. I took it for a drive and it ran perfectly. Nothing dropped out.
Thanks to all that offered advice.