get access to the solenoid. it is on the drivers side suspension turret. think it is a greeny/grey colour. there are a couple of fiddly bolts but nothing too bad.

leave the electric plug on it.
pull plastic pipes off it - make mental note of which one went where (only two).
get an old towel to stop too much mess - place solenoid in towel.
go in car drivers side. under steering wheel there are 2 pairs of connectors. 1 green pair 1 black pair.
join the green ones only.
turn ignition on - do not start car.
engine should cycle tests - e.g. fans spinning up and the boost solenoid should be clicking away.
squirt brake/carb cleaner into it. use copious quantities (that's what the towel is for )
you can also remove and clean out the pipes that run to the solenoid.
turn ignition off
disconnect green plugs.
refit solenoid and pipes.
check the oil level is halfway between the two holes when cold - this will prevent contamination.

 

Just my 2p worth. When I had exactly the same problem on my RB5 I put a manual boost controller on (Turbo XS High Per one to be exact).

Set it up carefully and completely eliminated the problem. This was after all the usual cleaning of the solenoid/pipes and ECU reset.

It was holding 15.1psi without any fluctuation or fuel cut

When I sold it last mth I took the MBC off and it was back to slight hesitation.

Car was also noticeably slower with less kick (obviously running higher than the standard 0.9 bar when it was on)

Neil

P.S Andys remap should sort u out but I've still got the MBC and I'm in Central Scotland if you're stuck.

 

Cheer mate, I'll bear your offer in mind.

 

Cheers from me also.

I'll clean the Solenoid first.

Failing that, I'll consider either a manual boost controller or a Tek3 remap.

(I've been looking for an excuse for a remap for some time )

 

Well thats the new spark plugs fitted (NGK PFR7B's) and the car is holding 14.7psi peak boost.

It already feels better, so the old plugs may well have been a contributing factor, but the car is going to Andy on Tuesday for a remap anyways, so 280-290bhp, here I come!

 

Had the car over to see Andy.F today to let him work his magic.

Seems the car was only putting out 199bhp, fully de-catted

Andy has now Ecutek'd the car and power is now closer to 250bhp, so feels worlds apart from it's old self, but it is still circa 30bhp under what Andy would expect given the mods.

The car is now pulling really cleanly and smoothly and feels pretty rapid, but thats partly due tot he fact that it was bloody flat beforehand! lol

Anyway, I've a couple of avenues to address to get the car into a healthy state prior to going back to Andy for another map to reach the target power.

The lambda sensor is gubbed (after the Subaru delaer told me it was fine! ) and there is a possibility that the turbo may be past its best before date!

So, onwards and upwards...... anyone got a TD05 lying around?

Watch this space!

 

I have something a little larger for sale

 

PM me what you got and how much John

Phill

 

Well, I have just purchased a VF28 from an STi5 with 29k miles under its belt, so once its fitted, its back to see Andy.F for another remap......

 

I got the VF28 and new lambda sensor fitted today, and I'm off to see Andy.F again on Tuesday for a map adjustment, and hopefully close to 300bhp!

First impressions of the new turbo?

The VF28 has a good bit more lag than the TD04 it replaced.
I fitted the VF28 using all the correct banjo bolts, except for the engine end oil feed banjo. According to Andy.F the increased oil flow to the turbo caused by the TD04 banjo shouldn't cause any harm, and only affect spool up time by 100rpm or so.
Does anyone reckon the increased oil flow could affect the seals?
Its quite funny to hear the turbo bearings spinning, even at idle, and although I haven't driven on boost properly until the remap, the car does feel quite strong in the midrange.

I just hope the increased lag/more power compromise is worth it!

I'll let you all know how it goes on Tuesday!

 

Had the car back to Andy.F today and got the map adjusted for the VF28 turbo. Result?

294 bhp
306 ft/lbs torque

I can't remember the RPM that the above figures were recorded at, but I'll post up as soon as Andy emails me the graphs.

The difference between the 3 stages of tune are quite remarkable and the 3 graphs show a staggering difference when plotted on top of each other.

Stage 1 - Full de-cat prior to remap - 199 bhp (well under due to knackered turbo)
Stage 2 - Full de-cat post remap - 246 bhp (even with a dodgy turbo)
Stage 3 - Full de-cat, VF28 turbo, remap - 294 bhp / 306 ft/lbs

The car now pulls like a train and even the lag is not noticeably different from the TD04.... just a slight hesitation but nothing to worry about.
After 5 Imprezas, this one has the highest power to weight ratio so its grin city! I don't see me getting many decent fuel consumption figures now!

Anyway, to say I'm happy is an understatement even though Andy said he would have expected a bit more power..... Need to look at the induction side I think.

Cheers to Andy.F..... top bloke who REALLY knows his Imprezas.

 

Cheers John, glad you like the new power curve Just watch for those flashing blue lights now

Andy

 

nice one mate. Glad you got it all sorted. 199 to 294bhp = result.

Good torque figure too.

Bob

 

My thoughts exactly mate!

I was hoping for over 300bhp, but when I saw that the torque was 300+, I wasn't too interested in the power tbh!

 

Just received the graphs from Andy.F and for anyone interested, the car improved as follows.....

Stage 1 - De-cat prior to remap ------ 199 bhp @ 5879rpm / 222 ft/lbs @ 3650rpm
Stage 2 - De-cat post remap --------- 246 bhp @ 5531rpm / 270 ft/lbs @ 3569rpm
Stage 3 - De-cat, VF28 turbo, remap - 294 bhp @ 6192rpm / 306 ft/lbs @ 4378rpm

So, 95 bhp and 84 ft/lbs of an improvement and my power to weight also jumped from 128bhp/ton to 164bhp/ton!

 

You car must be well overweight! You sure you have that right?

Classic with 294bhp/1235kg = 238bhp per ton

Bob

 

I typed this out on autopilot straight from the deltadyno graph.....

Perhaps Andy can tell why it gave the low figures? I assume the vehicle weight wasn't entered?

 

I would assume the weight was not entered. Easy maths though

Bob