Hi

Sorry if this has been mentioned before, I've done a fair bit of searching through the forum but to no avail (feel free to point me in the right direction)

Just picked up (3 weeks ago) a 2007 Skoda Octavia estate. Its the 1.9tdi. Not sure the engine code. its the 105bhp I think. Very good amount of service history.

IT was driving ok when I bought it. Seemed a bit slow, but never had a car like this size with this engine so I just assumed thats how it was. After a week or so, and even long drive down the country, it was returning really poor mpg. struggled to get it to 30mpg, and barely could touch 40mpg even with driving very frugal on the motorway.  So it didn't seem right.

So firstly I did find a piece of paper with a "tuning company" printed on it. not a receipt but after I contacted them. It had been mapped about 7/8 months ago. I explained the situation and he firstly denied it would be the map, and would have to pay to have their diagnostics checks done. So I took it to a local place to me that have really good reviews. He laughed when I mentioned this other company and said has for ever correcting their maps (£70 for some maps they do, so definitely best avoided) So had the previous work removed to stock and the stage 1 from this company done instead, EGR software delete etc. 

Car was fine and back to normal driving. but after a few days, the mpg situation was the same.

So checked the air filter. Clean and new. Checked the coolant temp sensor was reading correctly. It sat about 85c so I assumed thats good. Even though the EGR is now not in use. Its recently been cleaned. Cleaned MAF etc. Fuel filter was done less than a year ago.

But while doing this noticed. buried behind some wires and plumbing. a "DS Tuning" chip box thing. Guessing its one of those ebay specials that tricks the ecu into performing a certain way. I took it back to the tuning centre. He apologised that he didn't notice it and told me to remove straight away. 

It started to drive a bit "funny" as the day went one. Boost seemed to be coming in late etc. No massive clouds of smoke etc but really down o power. Then yesterday it wouldn't even reverse out of my driveway (uphill but not steep) without really working the revs and the clutch,

Now when I drive it, Its driveable. But no boost/power what so ever. Its like a tank. Id first assumed a boost leak. But it was literally after removing this chip box that it deteriorated.

So I'm going to plug it back in tonight when I get home and see how it reacts. But I just wanted to see what other peoples thoughts are on this?

Could the combinations of maps and boxes just be confusing the car. and is there a chance it could of done some irreversible damage?

Any hele would be appreciated, Sorry for the long winded post.  

 

And forgot to mention. the first map that was removed was bad. The tuning place explained it as:

Turbo pressures turned up too high

2 Torque limiters done and 6 left stock.

fuel pressure sky high

And egr not properly deleted/removed in the software.

Even though you think you may have issues with the tuning of the car I would still change the fuel filter first. You said you only picked car up 3 weeks ago but that's still a year of the previous owner putting who knows type of fuel in car, fuel could have been going in car out of dirty drums or even running it on red. Perhaps not but air and fuel should always be first to renew when power is down.

At least you'll then know you have clean unblocked fuel going to your injectors.

Also you said fuel pressure was sky high... and now its back to normal the pressure not strong enough to get through blocked filter.

 

Worth a try first. 

Edited 5 March, 20197 yr by Kris82

Thank you for the reply. And OK you do have a point. I'll change the fuel filter this weekend. Just to eliminate one thing at a time.

My mechanic friend has had it plugged in today and mentioned it having a problem with boost. So he's investigating down the road of the turbo vains and actuator etc. So I'll know more about that in the next day or two.

Just a quick question. When I'm looking at the car parts places. Euro car parts etc. It's bringing up multiple fuel filter options. Any idea how I find the correct part number for mine particular engine? Or am I best taking mine out and having a look/measure. Thanks

17 hours ago, octavia1990 said:

Thank you for the reply. And OK you do have a point. I'll change the fuel filter this weekend. Just to eliminate one thing at a time.

My mechanic friend has had it plugged in today and mentioned it having a problem with boost. So he's investigating down the road of the turbo vains and actuator etc. So I'll know more about that in the next day or two.

Just a quick question. When I'm looking at the car parts places. Euro car parts etc. It's bringing up multiple fuel filter options. Any idea how I find the correct part number for mine particular engine? Or am I best taking mine out and having a look/measure. Thanks

Take it out have a look, some are longer than others also some come with o ring others don't. 

Hi Kris, thanks again for the reply.

Will do.

the car seems to only have a tiny bit of power when this "chip" is plugged in. So basically only giving any sort of get up and go when its over fuelling.

The mechanic had a look over yesterday. He checked over the turbo actuator, vac pipes and solenoid, all good. EGR and boost pipes all good. The timing was out half a tooth and he readjusted it to be correct. But its still really down on performance. So if he gets time today.  Hes going to look down the fuel route.

Map sensor, fuel rail pressure and temp sensors etc. Hopefully he comes up with something. or ill probably just give up lol 

Thanks again Kris82

Still at a loss. He checked the "adjustment nuts" on the injectors that run of the camshaft (you guys probably know more about that than me) they're adjusted correctly.

Its still really bad MPG wise. I have a slight bit of boost about 2750-3000rpm but thats it really. rest of the range its still a bit slow. The mechanic still thinks its a fuelling issue. or lack of. He checked the fuel filter and it looks near new. So he's assuming its maybe the prime pump from the tank?

Does anyone else reckon its worth checking the fuel route? Even though its getting like 23-28 mpg when I'm driving around? 

He checked the pump at the engine at just over 90psi at idle which he says is in range.

So he's saying Prime pump by the tank, injectors or a blocked exhuat, but now I'm at the stage of just buying more parts to "test". I preferably don't want to just trade in and lose a lot of money. But at the same time, sell the headache onto someone else. Any more ideas?

Even though my mechanic has the proper Snap on diagnostics. Is it worth getting someone with a proper VAGcom ?

 

Thanks