Trampdrifting

Too many autocorrects in the above for my liking

Had a problem with my car the other day and found out something I didn't know existed that was causing me quite a few problems! CR170 Octy VRS 2009 The car 'Had' lumpy idle, flat spots and wasn't as economic as it was previously. It turns out there is a small valve in the head of the fuel filter housing, totally mechanical, once the housing was replaced the car felt like new again! I'd have never known it was there so just a tip for others to look out for. Simple test, if your cars got these symptoms then put a kink in the pipe that returns to the fuel tank, if the lumpy feeling clears this 'could' be your culprit! The problem is that the valve gets stuck and too much fuel returns to the tank starving the engine of fuel. Mine had total power cut of you tried to even build the revs up in the end so was an even easier test as the engine no longer cut out. The units simple to spit, it's in front of the windscreen washer bottle at the front left of your engine bay and has four pipes running in and out. These are to and from tank, and to and from engine, obviously don't kink them too hard or for too long, but a useful and free test to make before spending out hundreds on other items it could be!

It had flat spots when cruising on light acceleration, lumpy idle and felt a little down on power and economy. The valve is located in the fuel filter housing head, it basically diverts fuel back to the tank, completely mechanical so unsure how exactly it's controlled. But mine was returning too much fuel too the tank instead of into the engine, replaced this and now it runs like a dream again!

So, I had a Terraclean done on the car the other day for those who are interested and question its improvements and they are as follows: Octavia VRS CR170 Diesel, 105k miles MPG, since the terraclean I'm getting about and extra 2mpg on average DRIVE, it's ever so slightly more responsive and the whole process of accelerating and coasting along makes it feel a little more like it did when we bought it on half the mileage. OTHER, so, Terracleaning was a costly process on the day, although the service was only around £120 on the day, it's also aided my fuel return valve to fail. BUT, this was more than likely on its last legs and was probably the reason the car was running rough anyway. I'm guessing the cleaning dislodged the last few bits of carbon build up that was holding it together. But, having replaced this along with the cleaning done it feels like a different car. WOULD I RECCOMEND TERRACLEAN? Yeah i think so, it's probably a waste of time on a new car, but when you've done a few miles now as I have then you can actually feel the difference. It's not a wonder cure for the aging engine, but takes it back a good few 00k miles to a happier time!

Did anyone ever end up with the car on the forum after I sold it? Would love to know what happened to it after letting it go for nothing on a PX?

Thanks Tech1e, I'll hook it up and take a look. I think perhaps I'll see if I can pick up another sensor and take readings from both to see what I can rule out. Is the sensor the one to the left of the fuel rail?

So it may be that you can buy exactly the same light with the module to allow them to work on the canbus system.

This could be (like many of the bulbs) that it doesn't have a canbus interface / rectifier. For example, when I first bought my Mk2 Vrs I bought a Xenon headlamp kit just based on the bulb fitment, they were cheap but flagged up the warning light to tell me the headlamp bulbs were gone. I then spent some more money and bought a set that were designed to work with the Canbus system and they work exactly the same but don't create the fault. I don't think canbus is specific to the VRS so can't see that they would be selling lights that aren't compatible with the system, but, it sounds exactly like the problem I had. And as you said, you can't really fit them wrong. Take a look at the ones you bought online and see if you can find a set with and without CANBUS mentioned.

I know a friend who had something similar on his golf, it turned out to be a heater to pre heat warm air for the car in cold weather before the natural heat from the engine took its place? This was a strange foreign spec car but could be this? It was behind the glovebox?

Will the revs increase at all when you press the accelerator or does it do nothing?

Thanks for your reply! I've been off the forums for about 18 months now and it's good to see that it's still so active! I have VCDS so I could run some logs on this and see what it reports, my old MK1 Vrs lived on this as it was so highly modified, but, that's long gone and I've lost touch with it all! Could anyone possibly explain what blocks to measure etc so I can see actual against expected, I guess this could be easily measured at idle as it should be exact if the car is sat on the spot.

Hi, I've seen this in the forum a few times, but haven't yet found a thread that answers my problems, I'll keep it short and sweet to avoid rambling on. 2009 Octavia VRS, CR170 (not the PD engine) 104k miles If I accelerate hard the car cuts out at higher revs, the coil light comes on and the car rolls to a stop. When you turn the engine off and on again the fault clears and the car drives fine again. The car has just been terracleaned, has a new fuel filter including housing with valve, is freshly serviced and otherwise doesn't miss a beat and is brilliantly economic on fuel and perfectly smooth to drive. The problem has been present since about 70k miles and no amount of servicing or mileage has changed the problem or altered its characteristic is any way.

It's not the bolts I had a problem with, I've got the wobble set, it was getting the thermostat to balance in the hole while I lined the coolant neck against it. But then it was 30 degrees and I had been working on the car all day by this point! I think I was just still a little annoyed when I made this post

That's it for my post. Replaced mine last night, I'd rather replace the turbo again.

I ran mine with the SAI pipe bouncing round in my engine bay for a year and had no problems caused by that, so I'd start looking elsewhere for the answer for that one, as above something else has probably been knocked about during install.