Wont start after engine rebuild

Shmeeefly

Member
Hi Everyone

I have just rebuilt a 1.4 AUA engine and fitted it but it wont start for some reason and I cant seem to find a plug going onto a sensor just above the driverside driveshaft, I cant find the wire anywhere but wouldnt have thought it would be preventing the engine from starting ?? There is spark and fuel but no start ???

Can anyone help please maybe I have forgotten something ???

Just to note I rebuilt the engine because the thrust washers had fallen out and made a mess of the crankshaft and blocks, so I replaced both crankshaft and fitting blocks.

Thanks
 
Are you sure that the cambelt timing is correct.

Another thing to check is that your immobiliser is not the cause.
This is unlikely because it would fire up but die instantly and you would get the red car/key light in the dash.

Steve B
 
I'm 100% sure I got the tdc right with the notch on the crank shaft and alighnment of the two top ones with a strait edge,
 
the sensor on the back of the engine is the knock sensor , possibly without this connected the engine wont run , as for timing the engine , you can push 8mm drill bits into the holes in the cam pulleys to lock them to correct position as theres locating holes behind the pulleys machined into the cylinder head, if the timing is the slightest bit out they dont start ...
 
To repeat the above, alignment of the top end is not with a straight edge but by locking the cams. You need a tight fit and I’ve found 1/4” extension bars to be a perfect fit. The belt also has to go on anti-clockwise so the tensioner takes up the slack of the belt without adjusting the timing.

A couple turns by hand and checking the alighnment pins fit in the top end and the timing mark on the crank all line up and your good to go.

If you’ve got fuel and a spark, she should start.
 
the sensor on the back of the engine is the knock sensor , possibly without this connected the engine wont run , as for timing the engine , you can push 8mm drill bits into the holes in the cam pulleys to lock them to correct position as theres locating holes behind the pulleys machined into the cylinder head, if the timing is the slightest bit out they dont start ...

I'm pretty sure the timing is ok as i hand turned the engine several times and everything lined up as it should, and I didnt mean the knock sensor on the back of the engine, one above the driveshaft
 
theres also one that goes to the flywheel and is crankshaft position sensor in the same area, and for sure if thats not connected it wont run, from memory the sensor located against the flyheel by the cranckshaft and has a long cable attached to the sensor and where it plugs into is the other side by the oil seperator cambelt side of the back of engine
 
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you can see the crankshaft sensor and the knock sensor in this photo and may help you

aua engine.PNG
 
I am sure if the knock sensor is not connected it will not run - knock sensors cuts injectors
Also if the crank sensor is not connected it will not run - does not know where TDC is, therefore when to inject and spark
 
I am sure if the knock sensor is not connected it will not run - knock sensors cuts injectors
Also if the crank sensor is not connected it will not run - does not know where TDC is, therefore when to inject and spark

Knock sensors shouldn't prevent the engine running - the engine will simply drop into limp mode.

The crank sensor will definitely prevent the engine running - one of the few single modes of failure for the majority of petrol engines.

Have you scanned for error codes?
 
Knock sensors shouldn't prevent the engine running - the engine will simply drop into limp mode.

The crank sensor will definitely prevent the engine running - one of the few single modes of failure for the majority of petrol engines.

Have you scanned for error codes?

Yes scanned for error code but nothing :-(
 
Right :mad: I tested the knock sensor and that was fine, and now I think I have found the problem..... When I try and start it, it seems to struggle as if something keeps pushing the pistons back if you know what i mean, so i disconected the crankshaft pulse sensor and the engine turned over much better and even started to sound like it might start but didn't :( .... When I refitted the crankshaft i got the engine to the tdc and fitted the crankshaft reluctor ring with the hole at the top, is that right guys ??
 
Right the engineer in me has told me to investigate further into where i got my initial information from and I think I have found how i went wrong !! I watched this video -- https://www.youtube.com/watch?v=Lo6wpKdBoUE --- and he tells you to make sure the hole in the ring goes at the top, which is what i did, but now after watching the video back I noticed the gaps seemed to be different in the ring ??? :-( and now I have found this video ---- https://www.youtube.com/watch?v=1P32pveQ4ok ---- in a different language but he seems to be telling whoever to align the hole at the right hand notch at the bottom....

I've included images of the difference below
bad n otch.jpg the one I did but ring seems to be different

good n otch.jpg the one I think I should have done as it has the same ring in it with the gap in line with the hole.

Can anyone confirm this please
 
If it’s an AUA petrol engine the timing is by the helical cut tooth on the bottom pully, not the holes... hang on I’ll find a pic
 
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