hi friends i own 1.9 tdi skoda octavia, i had used bigger injectors,exhaust dia had been incresed.and made it as free flowing, added a tunning box from east coast racing, result is 1-observed inrease in torque at lower RPM, 2-the engine is not exceeding the 2800 RPM in any gear. can any one help please.the air intake is a big k& n air filter used in dodge ram ,changed the fuel filter,but still there is no change ? is the ECU cutting the turbo boost ? or is the ECU cutting off the fuel? any advice please .

Maf?

Can the fuel pump keep up with the requirements of the bigger injectors?

I think for something like this a proper remap would be more suitable as the ECU may be going nuts thinking it is heavily over fueling.

your engine needs mapping properly as you have changed some vital pieces so the car won't run right if it isn't controlled properly.

if you change the injectors the map needs changing to suit not just a tuning box gaffer taped to it

Most propably it is dirty Mass Air Flow sensor. If there is ANY excess oil in the K&N, it will foul the MAF. Aftrmarket airfilters do not improve performance on TDi engines.

You can test the MAF by unplugging it and driving around. If the performance is better when unplugged then you know it is the MAF.

See also MAF 101 from TDi-Club.

Bigger injectors do not necessitate a remap .

BR,

Vesa

A remap would however get more out of bigger injectors.

it depends on which injectors you have fitted really???

but my guess is that it's gone into some kind of damage limitation mode becuase of the larger injectors.

the standard fuel pump is more than adequate for producing over 200bhp so i dont think that is the problem...

normally it's nt the injectors which are the weak link in the pd engines... it's the turbo... the turbo cannot flow sufficient air to keep up with the fueling... if yours is a pd130 engine the standard injectors in these can flow enough fuel to make around 190bhp.

I heard the 90 is good with the 110 injectors and that the 110 is ok with the carvelle injectors, but i reckon that adding the tuning box to this combination could put the ECU into 'what the hell is happening mode' prehaps?

Does it go past 2k8 rpm with the tuning box off?

why wouldn't the map need altering after changing the injectors?? they would be injecting a different amount of fuel to waht the ecu expects so mixture would be all over the place.

Diesels do not care about the mixture. A diesel engine runs normally (low to medium load) with huge surplus of air. On full throttle the ECU limits the fuel amount according to actual Mass Air Flow. This is done in order to avoid smoke. The smoke map in the ECU is made so that the engine would not smoke under ANY conditions. So there is some margin that can be used for injecting more fuel. Slightly bigger injector nozzles will result in more power and smoke in SOME conditions. BIG nozzles will result in POWER with SMOKE.

Injection quantity can be tweaked with VAG-COM but it is not a remap in the same way as with petrol engines.

Vesa

thanks friends.this car is 1.9TDI.90 bhp version, the injectors are from KERMA TDI.does any one know the volume of injectors in terms of -cc.-i requested the kerma tdi. not yet replied? i would follow the procedure disconnecting the MAF ,and keep reporting thanks

thanks friends.this car is 1.9TDI.90 bhp version, the injectors are from KERMA TDI.does any one know the volume of injectors in terms of -cc.-i requested the kerma tdi. not yet replied? i would follow the procedure disconnecting the MAF ,and keep reporting thanks

is that a pd engine or is it a normal pump injected engine??

TDI 90 isn't a PD, quite a few people talk about putting TDI 110 Injectors in the 90 prior to a remap, but you can do it without the remap.

the only thing i can suggest is that the injector which have been put in may be dodgey or the pintle valve operates at a different opening pressure to the standard ones. they may have a different spray pattern too.

Had a quick look they do have a different spray pattern if you pick the non oem style models.

Which of the injectors did you pick from kerma, as to only updates i have heard first hand of working without the remap have been OEM for larger OEM ones.

Also having seen the price of those things a remap would have been the same price. $250 each :o:o

hi friends, as suggested i had disconnected the MAF & drove there is lot of improvement,its back to full power and to my surprise no smoke,earlier it use to smoke up a bit.do i run like this ?does it harm ? what is the end result is the MAF dead ? shall i replace with a new MAF or try cleaning? bye

Try cleaning the MAF, a search on here will help.

If that doesn't help you should replace it as driving without isn't good for the engine.

Most propably it is dirty Mass Air Flow sensor. If there is ANY excess oil in the K&N' date=' it will foul the MAF. Aftrmarket airfilters do not improve performance on TDi engines.

You can test the MAF by unplugging it and driving around. If the performance is better when unplugged then you know it is the MAF.

See also MAF 101 from TDi-Club.

Bigger injectors do not necessitate a remap .

BR,

Vesa

thanks man its the maf is the problem,disconnected it then its working fine thanks a lot bye

Most propably it is dirty Mass Air Flow sensor. If there is ANY excess oil in the K&N' date=' it will foul the MAF. Aftrmarket airfilters do not improve performance on TDi engines.

You can test the MAF by unplugging it and driving around. If the performance is better when unplugged then you know it is the MAF.

See also MAF 101 from TDi-Club.

Bigger injectors do not necessitate a remap .

BR,

Vesa

thanks man its the maf is the problem,disconnected it then its working fine thanks a lot bye

Tried disconnecting the MAF on mine today as i knew mine wasn't 100% happy and I get absolubtly no turbo boost at all when the MAF is off :S

On the plus point i found a really good solvent cleaner for the MAF too. It is

Servisol Aero Klene 50.

Seemed fine on the plastic, except for me worrying when i saw a layer of ice that built up on the plastic causing me to think it had reacted with it when it hadn't.

Off topic, but I saw a post here which said that the fuel injected volume can be tweaked by VAG-COM. Can the injected volume be tweaked for the 1.8T too?

The guys at Skoda dealers here tell me that VAG-COM cannot control fuel inejcted volume etc. It can only check for error codes and figure out if a sensor is not working.

I have always felt that my friends RS has a freer pickup below 2000 rpm than my RS. My RS feels a bit sluggish below 2000 rpm, but feels better after 2k to redline.

By the way I use 93 octane fuel and my friend uses Premium Unleaded 87 octane but claimed to be 91 octane by the oil company as that premium unleaded has additives mixed in it.

The different fuel will probably be it.

IIRC i thought hte Octy said use 91 Ron (min) 95 or 97 RON fuel

Off topic' date=' but I saw a post here which said that the fuel injected volume can be tweaked by VAG-COM. Can the injected volume be tweaked for the 1.8T too?

The guys at Skoda dealers here tell me that VAG-COM cannot control fuel inejcted volume etc. It can only check for error codes and figure out if a sensor is not working.

I have always felt that my friends RS has a freer pickup below 2000 rpm than my RS. My RS feels a bit sluggish below 2000 rpm, but feels better after 2k to redline.

By the way I use 93 octane fuel and my friend uses Premium Unleaded 87 octane but claimed to be 91 octane by the oil company as that premium unleaded has additives mixed in it.[/quote']--------------------- i do not know much in terms of technicalities, but i own a lexus aristo twin turbo petrol .here the theory is .once decat your turbocar ( removing catalytic converter from the exhaust pipe) will help increase the turbo boost hence more power .but ECU comes into play thru MAF. so they use electronic device FCD which will mask the MAF values and help increase in more fuel inturn increase the turbo boost.in the process you need more fuel to cope up with extra air volume so bigger fuel pump,and to protect the turbo to have a control on the turbo boost (not to over boost ) they use boost controlling device & exhaust restrictor rings so on .www.mkivsupra.net has got more info on petrol turbo

Tried disconnecting the MAF on mine today as i knew mine wasn't 100% happy and I get absolubtly no turbo boost at all when the MAF is off :S

On the plus point i found a really good solvent cleaner for the MAF too. It is

Servisol Aero Klene 50.

Seemed fine on the plastic' date=' except for me worrying when i saw a layer of ice that built up on the plastic causing me to think it had reacted with it when it hadn't.[/quote'] ------hi as of now its been a day running with out a MAF .but i need to go check the MAF condition ?i will post the result.

The different fuel will probably be it.

IIRC i thought hte Octy said use 91 Ron (min) 95 or 97 RON fuel

you're right! I used premium uneaded today instead of 93 octane and my car was freer than when I use 93 octane. Maybe it's because the RS had been detuned in india due to bad fuel quality in most parts of India. Will post update once I get the car Custom Coded.

Only thing is I can't figure out is the theory behind this as 93 octane is a better fuel than premium uneaded. any thoughts?