1.4 TFSI Not Starting

[adamofalltrades]

Hi all. Long time lurker, first time poster.


I have an Audi A3 8P 1.4 TFSI CAXC, that developed some gearbox issues. Whilst I was in the process of sourcing and fitting a new gearbox and clutch, the car was sitting on stands in my garden for close to 5 weeks.


I fitted the box yesterday, checked all the connections etc, which all looked fine. I then tried to start it, and the starter engages the flywheel and cranks (the revs on the tach go up to ~200 rpm whilst cranking), however the car does not want to fire. I pulled all of the spark plugs and verified that there is a spark (they were slightly black but not wet), tried cranking with a booster pack attached (battery at 12.6V) and also verified that there was fuel at the HPFP on the block. I am waiting on a pressure tester to verify that there is compression,
but the engine doesn't sound like it is cranking without compression.


I've scanned with VCDS and no codes have appeared. Fuel rail pressure is showing as 104.13 Bar, which seems to be unusually high.


The only unusual sign I've noticed whilst cranking is that there are noticeable pops and bangs out of the exhaust (there is a catback mod). Historically, there have not been any running issues with the car, there was occasionally a misfire in Cylinder 3, however this was intermittent and had no significant impact on running.


Any ideas/suggests on what the issue might be or what to look for?


Thanks!

[Crasher]

Whilst the box was out is there any possibility that you rotated the engine anticlockwise?

[adamofalltrades]

Now that I think about it, yes I may have rotated the flywheel anticlockwise when I was tightening up the pressure plate bolts. What impact does this have on the engine?

[Crasher]

There is no anti return spring on the tensioner, combined with chain wear, rotating anticlockwise causes the timing chain to jump, hence the popping and banging. Another point is operating the coil packs out of the cylinder with the plug not under compression can cause them to blow.

[adamofalltrades]

Sounds like I'm going to have to re-time the engine in that case. What you're saying makes sense, I completely forgot that it was a tensioner system. Thanks very much, I will re-time the engine and report back!