hi lads, just seeing if you vrs mk1 octavia lads are as helpful as the superb lads lol!

my son in law  has got a 2003 mk1 vrs octavia estate engine code AUQ with 147,000 on the clock that has now developed a problem. right this is the story i was given lol he as owned the car for ruffly 2 years + he was never told when buying the car if it had any mods done ie re map or internal engine work done, but it has got a strait through stainless exhaust a k&n air filter NGK coil pack leads and plugs dump valve  + some kind of performance clutch.

a couple of months ago it stared loosing some power when booted it drives perfect up until  it gets warm then the loss of power miss fire and popping and spluttering starts he then started to realize there was a buffing noise coming from the tank  so he took the filler cap off and it released a load of air and spitting fuel out of the hole if he left it running the buffing noise and fuel would carry on coming out only when he shut the engine off the pressure would dissipate he could get back in the car but would do the same thing again once the pressure had built up again.

any advice i would be grateful kev.

sorry for the long winded post, thought if you have all the details  you would be in a better position to give advice!         

Hi Kev,

 

The best thing to do as a starting base is to plug it in and get it scanned to see if there are any problems/codes stored. It would also be worth trying to find out if it has been remapped. Coil packs are known to go quite regularly with mapped cars if they’re cheap. Also, make sure he isn’t running an actual ‘dump valve’ as our cars are not designed to run with them.

cheers dean i will tell him!

why would there be so much pressure building up in the tank its actually spitting fuel out even with as little as a 1/4 of a tank ?

there is no way he can find out if its been re mapped or what ever but saying that he as just told me his mate has got a 2002 mk1 vrs with the same engine code AUQ box standard and it ant in the same league as his estate it, so me thinks something has been done/

cheers kev  

Has the fuel sender been removed & refitted? My experience is with a diesel but its likely to be similar with a petrol, I dont know what engine the car in question has but the sender is the same and the fuel suction & return lines similar.

 

If the pipes are connected the wrong way round the fuel pump has to work overtime sucking against the resistance that if correctly fitted would prevent the tank from being pressurised, this will manifest itself in several ways, a drop in performance (may not be noticable), a noticable decrease in fuel economy, air being drawn into the system and airlocks (a big problem on diesel but probably not on petrol) finally the whooshing sound when removing the fuel filler cap.

thanks for replies lads i will have a word with him see if he as done anything ! 

8 minutes ago, Kevgem said:

thanks for replies lads i will have a word with him see if he as done anything ! 

Let us know how you get on.

will do!