Been having some issues lately and it's slowly driving me mad. (Skoda Octiava MK2 2.0 16v BKD)

Okay, Few weeks ago, got the car back on the road after the ECU died (Water got into it, long story) Anyway, Replaced with another, unlocked, remapped, went home happy. Lately, driving it, All gears bar 5th and 6th is where it starts to get funny. Car will then start to shudder and stutter. Increase in noise but no extra go. Slow down a bit and it returns to normal. A while later however, the car then cuts out dead. No drama, just battery warning comes on and the engine is dead. It's a brand new battery and I've tested the alternator, it's not that. Car then turns over fine and strong, but won't fire.

 

Now I thought it was the injectors, but if one fails, it doesn't tend to knock the whole engine off. Had it before, was still drive-able, if a bit loud and lumpy. Tested the fuel pump, that's fine. Then thought it was the tandem pump. So I took it off, took it to bits and had a look inside. Nothing seems broken or out of place, So I put it back together again, put it back on the engine and it started. Quite lumpy and smokey to start with. Stalled. Tried again and gave the pedal a poke. Smoke cleared and it idled fine. So I took it down the road and back a few times. Seems to run fine. Think nothing more of it.

A few days later, I'm coming home after a nice weekend away and it dies again. Same as before. Felt lumpy/stuttery in 5th so I didn't push it. Less than a mile from home, engine dies and I coast. Side of the road, I checked what I could. Fuel pump from the tank working, fuel filter is clean (Well, as clean as it's going to be soaked in diesel. No oil on it and no sign of water/dirt/other in it) Pipes all fitted and tight, fresh diesel.

So, is it the tandem pump? I have a spare to put on it. But after I looked at it before, have I missed something? Also to be sure, I've ordered a whole new gasket set for the pump (And where it fits to the block) My guess, it might well be that. Taking the old one off and reinstalling it made the car run for a while...

Just trying to rule what I can and wonder if anyone had a better insight in case I've missed something.

Will when I can, drop into where I had the map put on and have them have a look over too.

Okay so I've done the following :

- Replaced the pick up pump in the tank
- Replaced the relay for said pump
- Replaced the fuel filter
- Replaced the tandem pump after stripping it, replacing all the gaskets

- Checked the injector loom

- Cleaned all connections that I could get to

- Replaced the MAF

- Checked for vacuum leaks

 

Then the moment of truth. Put a jumper on the battery and cranked and cranked for about 5 mins before spluttering into life again. Was not favorite of the month when I blotted out the sun in a cloud of black.

 

Now it's running again, I've replaced so many things I may not know what the issue was in the end. But also counting how long it will last. Last time I got it running, after two days the issue was back and the engine cut out.

Time will tell.

Well that lasted.

On my way to get an MOT as it ran out Monday. It died on me again. Same thing as before. 1st to 4th is fine. You get to 5th or 6th and it sounds like it's either, starved of fuel or over fueling. You change down a gear and then it sounds like an injector has failed. Drop the rev's down anywhere near 2k and the engine curls up and dies.

As I've replaced everything to do with the fuel system, I can only guess it's the ECU again.

Joy of joys.