hello everyone , recently i have done a BLT to Asz conversion on my mk1 vrs se due to blt failing , ever since the swap i have experienced, a flashing red oil light , and warm start issues , sometimes when the car is warm it won’t start again , it will crank and fire but won’t hold an idle . on the swap i have used asz engine loom&ecu , any help is much appreciated and can answer any questions

thanks:)

Hello, welcome to the forum.

Is this TSI or TDI?

For the oil warning, I'd first test what the actual pressure is by plumbing-in a pressure gauge to confirm that oil pressure is ok - if that's within specs, I'd suspect the pressure sensor.

For the warm starting issue, I'd check the crank and camshaft position sensors.

tis tdi mate , i will check oil pressure manually and make sure the plug is okay , as for the warm start i’m just a little confused as its intermittent when it’s hot and as for a cold starts it’s absolutely fine , just confuses me

Low cranking speed can cause failure to start warm in these I think. Try charging the battery and see if that helps.

Does the battery light correctly illuminate when you turn on ignition?

Your symptoms for warm start issues sound very like ones I have seen reported where the cam or crankshaft sensor was found to be the cause.

For oil pressure warning, disconnect the the single wire plug from the pressure switch and see if it has oil inside it. If it does that's a solid indicator of failed pressure switch.

for battery, the battery light will come on and then go off as normal when you start , i have checked the grounds as i know its a common fault, pulled the starter and it’s working fine , i can check both crank and cam pos sensors and i’ll have a look at the oil pressure switch , the only other thing i can think of is the fact that asz’s have oil level sensors and i dont have one , however thought that light was pressure not level , thanks guys

Yep, red light is oil pressure.

as for the low cranking speed or cam/crank pos sensor , would it make a difference when i say the car actually fires up just won’t hold idle , after 2-3 seconds it just shuts off

Sounds almost like immobiliser but can't imagine why that would only affect warm start.

I think with low cranking speed it wouldn't start at all.

Not sure on that though.

i’m 99% sure it’s not imo as ecu is de-immobilized

my freinds does a similar thing , and he combats it by holding the starter , until the turbo spools on idle which takes him about 3-5 seconds , mines more like 10-15 and if i try that i will just burn the starter out

Maybe bad coolant sensor/wiring. It can send wrong signal to ecu and cause poor starting when warm. Is the temp guage reading ok.

Alasdair

temp gauge on dash is spot on usually

Might be worth changing as there not that expensive. Read another sensor could be the air intake temp sensor. If its failing/bad connection ecu can overfuel. Dont suppose there are any fault codes?

Alasdair