E30 Zone

A while back, when i undid a the two bolts that hold the steering rack onto the subframe, the engine would not turn over, so assumed it was an earth, put the bolts back in, and it started up fine.

Now ive just swapped to an e36 rack, and the car wont start again, so im assuming its the same thing, but im using the same bolts, the only thing that is different is the washers to make up the tab difference. what needs to have a connection?

On the same point, the gearbox has been spacered up on higher mounts since i last started the car as well, could that be the cause of the problem?

Gearbox mounts would be my favourite for this. Once built a banger Granada and that wouldn't turn over but the handbrake cable and lever would heat up when you tried to turn it over. Same fix as that, run a dedicated earth strap between engine & paint free area of the main body (or direct to battery if it's under the bonnet.)

There should be a cable strap from the engine block to the chassis leg. Connect a booster cable from the chassis / battery earth and clip the other end onto the engine block, if it then starts then you need a permanent earth strap added.

cool, thanks guys ill try tomorrow.

Don't understand this one at all! There's no electrical continuity between the subframe and the engine - the engine is on rubber mounts, and I can't see it matters at all if the subframe or steering rack is earthed.
Starter current return path is from the starter motor mounting bolts to the engine, to the engine alloy mount, through the earth strap to the chassis rail, through the bodywork to the battery negative lead, and to the battery negative. The current shouldn't go anywhere near the steering or subframe.
The only thing that won't work if the steering column isn't earthed is the horn.

E30Mark wrote:There should be a cable strap from the engine block to the chassis leg. Connect a booster cable from the chassis / battery earth and clip the other end onto the engine block, if it then starts then you need a permanent earth strap added.

that worked a treat! thanks a lot man, an I dont get why its doing it either, but it is, and it can now be fixed! its had a 3.5 put in it so no doubt something is different, but hey, problem solved, thanks guys