Good day ladies & gents. Hope everyone is well. Im in desperate need of any advice regarding a weird problem im facing on a polo playa 1.6i afx engine. The car starts fine and drive until it reach temperature where the fan eventually kicks in but then the car loose power and when you give more acceleration it makes a sound in the throttle body and sounds like its starving for petrol then it just cuts out after few minutes and dies. When you try to start it again, the engine just swing and wont start untill it has completely cooled down.

The following parts where replaced already:
New coil,
New distributor complete,
New coolent sensor,
New thermostat 82deg.
New petrol pump,
Injectors & fuel rail coming off a running car...

Did a diagnostic and it doesnt pick up anything and there isnt permanent faults, ive even tested it with a open ecu and replaced ignition switch last night aswell. Antifreeze was replaced aswell with g12 antifreeze when thermostat was fitted. All fuses is okay, i dont have a service manual to see what relay feeds what but I've tried almost anything and was thinking of removing the head tomorrow for inspection & tests.

Any help or suggestions will be highly appreciated

so at the point that it doesn't start is there feul pressure?. Is there spark. Have you tested for an injector signal ? is there compression?
You can't just change stuff without knowing what there is and what there isn't . IE basic diagnostics not talking about plugging a computer in - just basic fault finding for the things that makes an engine run. Ie. spark, fuel, pressure.

The car starts fine and will drive for +- 50kms , the fan kicks in and would run like 4 times during that time and the temperature sits at half. I haven't tested for spark, fuel pressure during the time it starts loosing power and eventually dies. A friend was helping me out the whole time since I was in training for a month because i couldn't attend to the car. The coil had a cracked thats why i changed it and petrol pump had a problem with its flout thats why i decided to change the complete unit. Im not so good with the mechanical stuff and my thoughts waa the coolent temp unit or ecu and thats why i tested that aswell with a open ecu and a new coolent temp sensor. I'll start the car this afternoon and test for all those things when it starts doing the same and will report back. Thanks Panic

Good day panic-mechanic, ive tested the car when it starts giving the problem after it dies and just cranks there is still spark and fuel. Only need to test for compression once i get a compression tester

If there is spark and fuel the car would start... Did you try maybe kick starting the car thereafter? Could be the spark that you are seeing is too weak.

yes you will need to test for compression. Could be lifters pumped up from too much oil pressure. Which leaves the valves standing open slightly.
You leave it for a few hours and they go down and the car runs again

Good evening, ive only managed to get a compression tester today and got the following readings

Cylinder 1: 10
Cylinder 2: 9
Cylinder 3: 10
Cylinder 4: 10

Above readings were the same in both conditions where the engine was cold and hot after it dies. The spark is pretty strong and grounds are all good , fuel is still there so now im not sure what to test for anymore

No if you have spark, fuel and compression it will run.
One of them goes missing at the point where it dies otherwise you would not have this thread.

Good evening thanks panic-mechanic, I'll just go over everything again tomorrow after work when i knock off a bit earlier to re-check everything

test compression when it dies. Not when It's running OK.

panic-mechanic wrote: ↑Thu Aug 23, 2018 8:08 pm test compression when it dies. Not when It's running OK.

He did that. See below.

Golfie.NC wrote: ↑Mon Aug 20, 2018 10:32 pm Above readings were the same in both conditions where the engine was cold and hot after it dies. The spark is pretty strong and grounds are all good , fuel is still there so now im not sure what to test for anymore

You can rule out the compression, from what you've written.
I would also think that you can rule out the spark, if it's strong. I don't think the timing would suddenly change.

This leaves the fuel and/or air-fuel-mixture.
Have you had a look at the spark plugs after the engine dies? [Edit: e.g. for signs of fouling or flooding]

Good evening, i haven't had a change to test everything again but the other day ive tested on the injector plugs and got a 5v reading. Not sure if thats correct and the spark plugs have a brownish colour. Should i remove the fuel rail and test the injectors and what about the fpr on the rail?

panic-mechanic wrote: ↑Sun Aug 12, 2018 7:39 pm yes you will need to test for compression. Could be lifters pumped up from too much oil pressure. Which leaves the valves standing open slightly.
You leave it for a few hours and they go down and the car runs again

Good morning panic mechanic, i would just like to ask for advice regarding the hydrolic lifters. What do you suggest if it may be the case that it causes the valves to stay open because of too much oil pressure? Should i have a look at the hydraulic lifters , should i replace them or how should i test them?

You already wrote on 20 August that you tested the compression at the point where the engine doesn't start. Those readings were fine, and this means that the valves are not remaining open. Based on those readings, there is no need to check or replace the lifters at this stage.

The no-start must therefore be related to spark (timing) or to fuel delivery.

Check the fuel-pump relay

Supervan II wrote: ↑Fri Aug 31, 2018 3:32 pm Check the fuel-pump relay

Have replaced it already (relay 167) & relay 18

VAG Fan wrote: ↑Fri Aug 31, 2018 2:06 pm You already wrote on 20 August that you tested the compression at the point where the engine doesn't start. Those readings were fine, and this means that the valves are not remaining open. Based on those readings, there is no need to check or replace the lifters at this stage.

The no-start must therefore be related to spark (timing) or to fuel delivery.

Today ive tested the car again and drove around the block then took it for a longer distance and at some point it started loosing power and could hear like a type of misfire at the back and have to down gear to pick up abit of speed until it lost completely power and have to go off the road and it just swang again untill it cooled off and temp was just below 70 on temp gauge

Golfie.NC wrote: ↑Fri Aug 31, 2018 8:02 pm

VAG Fan wrote: ↑Fri Aug 31, 2018 2:06 pm You already wrote on 20 August that you tested the compression at the point where the engine doesn't start. Those readings were fine, and this means that the valves are not remaining open. Based on those readings, there is no need to check or replace the lifters at this stage.

The no-start must therefore be related to spark (timing) or to fuel delivery.

Today ive tested the car again and drove around the block then took it for a longer distance and at some point it started loosing power and could hear like a type of misfire at the back and have to down gear to pick up abit of speed until it lost completely power and have to go off the road and it just swang again untill it cooled off and temp was just below 70 on temp gauge

This sounds like a classical case of an overheating/faulty fuel pump - check all electrical connections from fuse box to pump, seeing that the pump is new. I'd refit the old pump, if it was working, for testing purposes to rule out fuel starvation.

yes and so will simply installing a fuel pressure gauge and that is what I have been saying about doing diagnosis. no use guessing.

Good day, old pump is fitted but stil do the same. Once ivr managed to get a fuel pressure gauge then ill trst the pressure and give feed back. Thanks alot everyone fot the help and responses so far. I appreciate all the help i get