Various Electrical Gremlins

[HarryW]

Thank you!

Will have a look into this. I’ll investigate, though I think some of this may be beyond my capabilities! Good as a pointer if I ever find a garage with time to look at it (for some open wallet surgery no doubt).

Nice to see an xj6 in the video also. That was a familiar view when all my old ones required the bonnet up for various issues.

[donp38]

Sounds like it could be MAF related.
VCDS is required, don't simply put parts on it.
I use David Lees Motor Engineers in Alcester.
All good experience.
Good luck..

[HarryW]

Thanks donp38!

Will add David Lees to the list. Not such a huge distance from Rugby so worth a try.

[strummagnet]

Originally Posted by HarryW

Thanks again!

Come to think, it has failed to re-start when at least warm. I'll have a go over the weekend hopefully...and try neutral wiggle and check the earth strap!

Is it a slow lazy crank when hot? That was my issue when the earth strap had worked itself loose.

[HarryW]

Always a pretty eager crank tbh. Not discernibly different to normal. It just doesn’t start. Did move it today to clean it a bit. And now it’s just refusing to start again. Ahhhh. Old cars.

[steamship]

Originally Posted by HarryW

Did move it today to clean it a bit. And now it’s just refusing to start again.

So it would have been relatively cold when you tried starting it again.

Did you check the battery terminals and the earth strap underneath the front leg chassis leg? Was it an exterior wash, as that could be a pointer?

[HarryW]

Have had a look for the earth strap. Is on the attached ? It looks covered in all sorts of shi* which I guess doesn’t help. I did have a duff oil pressure sensor sorted last year which might have helped coat some of the car in oil
I’m not sure.

Have had a bit of a clean of the terminals.

Tried starting in N.

It was a wet clean yeah. So at least it’s a bit more shiny now. It just doesn’t want to go. Swings and roundabouts. Could be a contributing factor?!

Bit of a puddle around the wiper motor area but I can’t see or feel any dampness elsewhere. The passenger footwell seems dry still.

Still cranking happily but not started yet.

[steamship]

I think all the earth straps look like that. It's worth opening it up to see if the connectors are clean and free of any oxidation. The oil pressure switch shouldn't cause any oil spillage, unless they tried replacing it with the engine running.

I wonder if it would be worth checking out the ECU box in the plenum chamber, to see if there is any water ingress there, and if so, is there any oxidation on any of the ECU connectors. Although it doesn't seem to be a case of it not starting every time it rains or you wash the car, it would be something to rule out.

EDIT: Do you have VCDS or some other way of scanning the car for error codes? Don't know why I never asked that at the beginning, as there may be something obvious from the codes. If you do, scan the car, save the log file and clear all the codes. The next bit is awkward (since it's temperamental at starting), but you then need to take it for a drive and scan it again (and save) to see what codes reappear.

[HarryW]

Thanks for that!

I haven't been in the ECU plenum yet actually, I'll have a look there next time and see how it's looking.

I don't have VCDS, i did have an OBD II dongle a while back. I could get an app on the phone and see if it reads anything.

I noticed the orange TCS and check engine light were on during cranking but can't remember if these stay illuminated usually anyway?

[donp38]

vcds is a must...anything else is simply guess work.
if you are cranking over and no start then the autobox inhibitor could be at fault
but please VCDS first is a must