stpreston

When the engine is hot (normal temperature) and i boot it over 4k revs the engine does a hesitation and stutters. It's very annoying. It only does it when its hot never any problems if the engine is slighty cold. Also if you only put it on half throattle you can increase your speed but only slowly, its almost as if the car is getting too much or too little air/fuel. I've been around the car and secured all the hoses and clips so its not that although there is a light grey connector plug next to the air flow meter on the left of the engine bay that isnt connected to anything, and i cant work out for look nor money what it is supposed to be coonected to.

I've had a look at a few things and the filter looks brand new, the air flow meter looks ok but i cant tell forsure if its working correctly, all the hoses and connectors are on bar the one ive mentioned.

How else could i work out what is broken as oppose to trial and error and replacing things!

any ideas on what to try or who to see.

Simon

Bristol

joz8968

iTrader: (13)

The plug to the air flow meter (MAF) is light grey from memory. Are you sure it's not supposed to be connected to the MAF?!!! Check the MAF - it'll be obvious if there's no plug connected to its moulded connector...

stpreston

cheers for the reply, no that connector is attached, this one is light grey. Will get a pic later, its no obvious where it should attach, any clues?

joz8968

iTrader: (13)

Yeah, post a pic up of it and the surrounding area, etc.

A pic paints a thousand words and all that...

stpreston

Any other hints as to what the hesitation might be?

myblackwrx

iTrader: (1)

Faulty MAF,plugs or ignition leads.

With the MAF you can test the voltage across it,plugs you can check yourself (condition and gap) same with checking the leads

DeanF

iTrader: (1)

My98 ? Does it have a single Coil on top of the inlet manifold with 4 HT leads , 1 leading to each head ?

I would put my money on Spark plugs first off, Either thay have been recently changed & gapped incorrectly (too Wide) or they are now due for renewal & are worn..

The effect you are getting is the spark being blown out by the Boost, Thats why when you accelerate gradually it is Ok, But a quick surge reduces the spark... It could be the Coil, But i would start with plugs first off, Gapped correctly !!!

Cheers.

Dean

stpreston

sweet thank you,

Do i need to re gap plugs if i buy them online? if so how? and if not where would you suggest getting them from? ill try that first, then leads.

myblackwrx

iTrader: (1)

Always check the gaps on spark plugs before fitting use a Feeler gauge (0.7mm seems to be the standard gap size).
If the gauge doesn't go in carefully bend the arm out,gauge is slack (gap too big) carefully bend the arm in

joz8968

iTrader: (13)

Yeah, NGK PFR6B plugs gapped at 0.7mm should be okay.

As eluded to, the gap is correct when you can feel a slight dragging resistance on the 0.7mm-sized feeler gauge blade...

brashy

you are better setting the gap to 0.65 and try that if it still does it shorten the gap to 0.6 but no less and if it still does it then its probly your coil

joz8968

iTrader: (13)

Yep, good advice this ^^^

stpreston

Some pics of the connector in question, spark plugs being changed Monday.

burbling1

iTrader: (1)

That to me looks like a cat on fire sensor. Have you got a decat?

Adam K

But that doesn't look like a MY98 to me... Rather a 90 deg bend turbo inlet pre MY97

stpreston

yeah a decat'd straight through exhaust and its a 2.0 WRX import, imported in 1998.

joz8968

iTrader: (13)

Yep, defo a cat-on-fire sensor connection - same as my MY1993 one.

So seeing as OP has decatted car, then it obviously doesn't connect to anything anymore (just make sure it's secured away safely...).

stpreston

coolies, cheers