Nick_Scooby

Had a decat downpipe for a couple of months and its been accelerating smooth through every gear so I'm sure it isn't this cause the following problem.

But........... Over the last few days, acceleration hasn't been as smooth anymore.

For example, I came to a junction, when in to 1st, then booted it, got to 4000rpm, then died, then came back. Like rooooom err roooom, felt like something was blocked! It can do it in any gear, at any point in the rev range, just seems to die for a fraction of a second, but enough to bloody annoy me, and it NEVER used to do it,!!! Though I'll try and accelerate from stand still again, and it may not do it!!!

Any ideas why it was smooth now like this?

Rince

Is this possibly the dreaded MAF? Been told by a few peeps that this is the problem with mine. Virtually the same kinda thing.

Heple

What model/year car is it?

Craig

Nick_Scooby

sorry!

it's 1994 WRX.

Heple

It does sound like a MAF issue but it is very rare they go on the 94 models.

I'd be tempted to fill up with v-power and reset the ECU just to see if it could be some dodgy fuel.

Is it an import?

If so are you using the correct fuel? i.e 98 or 99 ron

Are you using an induction kit?

If so which one?

Craig

Nick_Scooby

Yeah it's an import, I'm using, and always have done as owner, V-POWER.
I just have a STI Panel Filter.

Could anything have got wet? been a lot of snow and rain, could water have got into something?

What about some fuel cleaner additive"?

Heple

It sounds like you have been doing all the right things.

Maybe something could have got wet but if so, you shouldnt get any problems once the car has warmed up.

I wouldnt put any fuel addatives in.

I'd reset the ECU and see if that gets you anywhere.

Is the car's idle ok?

Have you checked the ECU for fault codes?

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Craig

2pac

are these 'MAF' things i keep hearing about easy to correct if they are going silly?

Heple

Normally involves replacing the MAF sensor.

These problems are only common on the 99/00 model classics so i wouldnt worry unless you have one of these models.

Craig

Nick_Scooby

It idles fine, it's a bit juddering the morning especially if it's damp! but I think that normal according to other owners.

If I just disconnect the battery over night, will that be good enough?

Are fuel additives not recommended? I.e Power Boost etc.
Thought it may clean out any blockages

Heple

You could just dis connect the battery overnight and that will work.

or you could do it this way

Scoobypedia | Trusted knowledge for everything Subaru | ECU Reset browse

The only reason i would not put fuel addatives in is because you need ideally need 100ron fuel and the addatives could weaken your already weak fuel mixture.

Plus i have never known anyone to use these additives.

If your car is consistantly idling lumpy you could have a faulty lambda but this shouldnt cause problems high up in the revs.

Check your ECU for fault codes 1st.

Craig

Nick_Scooby

Ok, I will check error codes after work.

It only idles lumpy when cold, once the temperature needle is in the just under half way mark, it runs smoothly.