84 350i wiring diagram

[Markymark21]

Hi All,
I am in Bromley, so I guess Essex is doable at a push. Thanks for the offer. Where abouts in Essex?

Hi Adam,
I have measured the CTS several times and appears good. I have also bridged it out to remove it from the picture and it still overfuels. I’m convinced the CTS and wiring is ok.

Thanks!
Mark

[adam quantrill]

THe other thread on here reminded me of a reason for a 30A fuse being installed, which is an electric steering pump, if you want to check for that.

[BlueWedgy]

Hi Mark,

I am in Harlow not far from the Hospital, easily accessible from the M11. Yes about an hour away I guess.

Have you checked the earths passenger side rear of head? I had an intermittent instant loss of power the earths were loose.
Also, the breather hoses are not blocked and the AFM hose is sound, big round one (no air leaks).
Injector wires under the boots crack and can touch. Although that is a real long shot as it will still start on four (one bank).

All of these caused my non-starting and running problems at some point in my short 6 months of ownership.

Edited by BlueWedgy on Monday 5th April 13:23

Edited by BlueWedgy on Monday 5th April 13:24

[Markymark21]

Hi Adam,
I’m going to come back to the 30A fuse. No evidence of PAS but has some cooling fans fitted with override switch. My investigation will start there.

Hi Bluewedgy,
Seems you’ve had fun too. The earths looked sound but I still took them off, cleaned them and put back. I don’t think that’s a source of the problem. The AFM hose is old looking and I plan to replace, but doesn’t have any obvious holes or leaks. I’ve not looked at the injectors but I’m getting the same on all cylinders from inspection of the plugs so I’m not thinking the problem lies there....

Regarding the kind offer to borrow an ECU, I’m going to see what the repair shop say when I contact them tomorrow. They’re only in Greenwich so maybe I can go there and get them to look at it. If they don’t play ball, I may be back in touch.

Thanks all for your help....Mark

[BlueWedgy]

My fan is running off a 20 amp fuse. The fuse did get hot to the point of beginning to melt it, I put this down to poor connection. To be honest the wiring that I have seen is poor and really needs a good look into.
As a temporary measure, I made it remote the spades used were longer than the fuse and make a much better contact in the fuse holder block.
If you have 4 blocks of 7 fuses have a look here, this is my fuse block allocation:

Edited by BlueWedgy on Monday 5th April 18:19

[Markymark21]

Hi All,
I just wanted to let you know that it was the ECU that caused the problem. I now have a running TVR.

I’ve started investigating the electric fans that are fitted. There are two of them behind the rad (between engine and radiator). Label on one says Smiths Industries. Could these have been an original fitment? They are old, but seem to work. Only trouble is that when they are running the idle speed drops a lot. If I set the idle where I want (900rpm) the car stalls. Hmmm....

Thanks,
Mark

[KelWedge]

As i have just read this, and the original question was, anyone got a wiring Diagram?

I have (yes its printed on something called paper!) its from a bit later,
Wiring Diagram dated 25/11/88 TVR Engineering Ltd
It was in the history file when I bought my wedge

In case anyone ever needs, but, we all know every car was not the same as the car before it.

[Markymark21]

Thanks. I’ve managed to download this one...

[Markymark21]

Another question - sorry - at the fuel pump with the engine running I have 12.8v. At the battery I have 14v. Is a voltage like that to be expected or could I have a dirty connection somewhere? Thanks...

[adam quantrill]

THe wires in the wedge aren't mega thick, that might indicate a volt over 4 metres at 5A ish? So 0.2 ohms?

You could check the earth part of it separately, what's the volts between the -ve pump to the chassis nearby, as a corroded earth connection is easily fixed.

[Markymark21]

Hi Adam,
I will check that. It looked to me that the earths typically come out of the loom. I’m guessing the chassis is grounded to the battery negative. Where would I find that earth point out of interest?
Thanks
Mark

[adam quantrill]

Battery -ve to engine, then engine to chassis. Connections behind offside cylinder head.

[Markymark21]

Hi All,
I had a good look without getting the car on a lift and cannot see the earth to the chassis from the engine. I found an earthing point on the near side chassis suspension upright that has an earth connection into the loom (lots of black wires) and to the AFM. I fitted another earthstrap from that point to a bolt on the water pump as I figured it wouldn’t do any harm.
Having done that the car seems happier. It doesn’t stall when the fans cut in now, so I guess it’s made a difference.
Next thing is to get the car out and do some miles to shake it down.
Thank you all for your help to get to this point....

Mark

[adam quantrill]

You reminded me - sometimes the earth to the instruments comes via the bonnet pull cable - I kid you not!

Also there should be an earth strap from the gearbox to the chassis under the car, which might be the only one, and sometimes it gets broken/corroded etc.

[Markymark21]

Thanks. I have an earth to the bonnet catch. Will look further. I need to get under the car again soon so will look for earths there too.