Mk3 needs more power!

[Laner]

Hey, my first post and my first golf! have to admit it wasn't my first choice in car.... well it was probaly my last tbh but i have to admit i love it to bits, yeah it may only be the 1.8 8v and a 5dr but it is still the best car i've drive and owning a merc 190e before this is hard to say.

Well as the title says i'm looking to get more power out of the amusing 90bhp stock engine. Current mods include custom induction kit(samco and alloy ram pipe with k&n element and cold air feed. Decat and free-flow back box. <------ advice wanted *

the next plans are nology leads and plugs with a voltage kit, maybe 4-2-1 and removal of the middle box leaving just the single back box and maybe if money is available either new throttle body off a 2.0 8v or a complete new inlet manifold?

What are your opinions on the ideas? don't worry about being harsh it's the only way people will learn lol.

* any ways about the exhaust i've done it's a 2" system with stock manifold connecting to a custom build de-cat pipe runing to the middle box just before the rear beam and then to a universal freeflow backbox, i'm currently concerned about this as the exhaust only makes any form of noise on idle asoon as the revs go above 2000rpm the exhaust just hisses(no deep normal noise at all?) then on release depending on revs they will drop very slowly (from 4000-limit) or will suddenly drop right back down the 900rpm with a large suck at the end as if the engine is trying to stall but never does? Also if started with nothing being pressed on the accelerator pedal the engine will start shudder and make a loud bang/popping noise from the thrrotle body and then idle fine at 900rpm, also occasionly whenpulling off the engine will hesitate for a brief second then pick up fine. the only thing i can think is either overfuelling which wud make sense due to the de-cat and induction kit, or too little back pressure?

Any ideas?

Cheers, andy!

[rubjonny]

1. Dont bother with expensive leads, just get some decent oem quality ones along with new tripple electrode sparkies from http://www.vwspares.co.uk.  A spark, is a spark, expensive leads wont give you any more performance.
2. 4-2-1 is a worthwhile investment, but only if you plan to stick with your 8v lump for a long time, or plan to upgrade to a 2.0 8v GTI lump later.  It wont fit on a 16v engine, so if you decide to go that route you'll have to buy another...
3a. Throttle body from a 2.0 8v wont fit as the 1.8 90bhp lump uses a SPI (electronic carb basically) and there's no way it will go on.
3b. 2.0 8v inlet manifold wont work either as the inlet ports are a completly different shape, and you would have to convert to fuel injection even if it did.

I'd look into fitting a MK2 1.8 GTI head, it has bigger valves & the GTI cam which will bost power straight away, or just fit the GTI cam if you don't fancy swapping the head. (Though if you do you'll be able to fit your 4-2-1 manifold at the same time!)
Only issue with the GTI head is it doesn't have the inlet manifold coolant channel hole in the back, which I believe your old head will have?  I know MK2 carb enginers do, but not 100% sure on MK3 spi, hopefully someone can confirm.  Oh and it has injector holes, you could just leave the injectors in though

Your problem sounds to me like either your coolant temp sender or the lambda have packed in, or both!  I'd start with a new blue sensor then look at the lambda

[Laner]

Thanks for the info, Probaly wud go with a complete head change assuming i'd have to stick with the 8v or wud the 16v head fit? i've done head gaskets before but only on cvh engines which are simle as. wud you recommend a garage to do the head change or is it fairly easy? only thing that wud concern me is i drive 80 miles a day to work and if i make a mess it's my only car lol. thanks for the info tho!

[Laner]

Also just a quick addition, where is the lambda sensor on my veichle as when removing the cat i didn't see one? i always thought they went just before or after the cat, can never remeber lol. also if the temp sensor was faulty wun't that cause the fan to be at fault too? strange thing is it seems to run fine when cooler rather than hotter? wierd!

[rubjonny]

1. 16v head wont fit. Head swap is a DIY job, but theres allways the possibility that something will go wrong!  When I did a zaust swap on mine one of the studs sheared off so I had to get the head off to drill it out.
2. Its in the downpipe somewhere before the cat
3. Nope as the ECU temp sensor is seperate from the dash gauge & radiator fan sensors

[Laner]

Cheers mate, looks like i've got a busy weekend ahead of me! just to find the sensors now...........