Hi

Any help gratefully received on this perplexing matter.

I have a 2011 Mazda 3 1.6 td. It has been running just fine for the last 5 years until the cam belt snapped.

I sent the car half way up the country for a replacement second hand engine. (essentially just the main block). All the usable parts from the old engine were transplanted across. While the engine was out they fitted new glow plugs, cam belt, water pump, clutch just for good measure.

Car reassembled, they turn the key, do the test drive all good. Go to re-start the car and it cranks over but no ignition. Car gets bump started but again when turned off the car won't start.
Auto electrician called in, does the readings, glow plug relay!!

Glow plug relay replaced, car starts first time. Car turned off and back on several times, victory we say! .......No! Try to start and yet again back to a cranking engine.
Auto electrician called, Cant find any faults.

Erm........anyone? Anything of use?

There was a suggestion of immobiliser but i'm thinking surely it wouldn't bump start if that was the case.

 

Update

The car starts and runs fine from cold and will continue running.

The issue is restarting once warm. The car won't restart on the key and becomes very intermittent, for example 1 time in 10 it will fire straight up, the other 9 times it will just be turning over.

Anyone come across this fault?

Oil temp or oil pressure sensor maybe?

 

Has it been scanned for codes? Has the battery been professionally tested? Does the glow plug light illuminate when the ignition is turned on?

 

Hi grim_reaper

Yes it was scanned for codes for several hours im told with no codes showing up.
The issue is only on a warm engine.

I have't asked the garage if they tested the battery but i do know it's been on long runs and that when its turning over its strong. They have replaced the key battery though.

Yes the glow plug light illuminates. Re starting apparently makes no difference if you don't wait for it to go out, do it while illuminated or wait for it to go out.

I have asked them to look at the oil pressure sensor, crank arm sensor both of which they say to be fine.
Thanks