I've got a '94 WRX. Just had a ScoobySport exhaust put on, replacing my HKS.

Now, when the engine is under load, it cuts out for half a second at 5,000 rpm, and then picks up again??

Any ideas?

Help?

It's broken!

 

Does it only happen in first gear ??

My MY96 does this if you accelerate really hard in 1st gear, but is fine if you accelerate slightly smoother, don't know what causes it though.

Stuart

 

Your hitting the overboost fuel cut defender due to the wastegate having less back pressure......probably!

 

hi had exactly the same problem with my MY97 when i fitted my scoobysport downpipe,but i managed to split a vac hose while working on the car did'nt no i had done it,and it took about 4 days to find,on mine it was the little 3" long pipe to the actuater from the inlet manifold,its worth double and treble checking this as i missed it a few times,,

 

It does it in all gears (mainly 3rd and 4th).

It sounds like the overboost thing though - thanks James.

How do I stop it??

 

Thanks Robert - could be that too- I'll check the hoses tomorrow.

 

It is overboosting almost certainly.

Mine did this for a while after the dealer replaced a piston. The cause was a split in one of the hoses leading from the manifold to wastegate actuator.

Assuming you've checked the hoses amd they're ok, then stopping overboost is a little more difficult. Short of replacing the ECU or adding a piggyback ECU, changing the restrictor (small piece of brass with a small hole drilled through it, hidden inside one of the above hoses) for a slightly bigger one may cure things. Very small changes to the restrictor hole size affect its function so only change by increments of 0.1 mm at a time if you decide to try this.

D.

 

Steve,

You haven't had an oil change recently have you ? My STi 3 did this when I bought it. The garage had serviced it and filled the sump with too much oil. This then allows oil to contaminate the wastegate actuator. Cleaned it out with aerosol carb cleaner, dropped half a litre of oil from the sump and this sorted it. Look in the SIDC FAQ for more on this - it's a common problem.

Kevin.