Zetec 1.8 won't turn over

[Maxakarudy]

Hi everyone,

I need a bit of advice, I've got a 96, 1800 zetec in a space frame chassis connected to an mt75 g/box, running a standard ecu. The engine was running a few months ago, no problems it's done 86k.
I'm doing some body work, but while the car is stripped down Im thinking about freshening up the engine, but want to do a compression check. The engine won't spin over fast enough on the starter to check, this what I've done and checked :-
Disconnected ecu, good battery, new starter motor, plugs out, throttle body open, jump leads connected directly to starter,clutch pedal depressed and in neutral, still spins slowly. If I put the plugs in it'll turn once only. If I put a socket on the crank it turns freely, no plugs, with plugs in it turns ok I can feel the compression.
I know it's going to something really obvious, but I just can't see it yet?
Cheers
Martin

[AlanH1]

Had a similar issue many years ago but on a bike. Replaced the jump leads for better ones . Discovered by using two pairs of leads. Also had a poor start with a bad earth strap on the engine case.

If correct power is getting to a good starter it should turn.

Edited by AlanH1 on Monday 13th May 23:12

[LuS1fer]

Possible earth strap issue.

[JU5T1N]

1.8 with a mtx75? shouldn't it be an IB5?
All I can recommend is making sure the boots fit ontop of the sparkplugs properly, mine was a real bugger