This isn't really worthy of putting on the Projects forum, because it's probably too lowly to go on there, but to me it was quite a mission so I'll go over a bit of it here, all two weeks' worth of evenings and weekends in the garage with the temperature hovering around freezing! Perhaps there will be some bits of my mini project on my MY98 WRX wagon that will help other Scoobynetters out in the future.

There were originally a few problems that needed fixing -

• a split in my turbo inlet hose
• an occasional knock spike showing up on my Power FC on the overrun or very light load
• a dodgy idle when cold and sometimes it would stall
• an alarm that had lost its arming chirp
• a bouncing speedo needle
• a snapped off rocker cover bolt which had left its thread inside the head
• new 'Green' panel filter needed fitting
• a recurring problem with a light/non-returning clutch

As is usually the way with these things, as I went along more problems turned up (or opportunities to fix stuff while I was there, if you want to look at it another way).

So first thing was to have the intercooler off and expecting a big job, remove the battery. Easy enough. At first, following advice on here I tried to get the original inlet pipe out by hacking pieces of it off an pulling like hell. First thing I learnt - don't ever think of doing this job without removing the inlet manifold first. Taking the inlet manifold may be a huge job (well it was to me at least) but it is a hundred times easier than trying to remove an original Subaru pipe and replace it with a silicone one. It was just basically a case of removing the power steering and coolant tanks and all the wiring and vacuum/coolant plumbing all over the top of the engine bay. Not fun, but not too bad as I was labelling every single wire, plug or hose as I went.

While I was there, I dismantled the alarm siren and replaced the nicad battery in it for a tenner, rather than by getting a Clifford dealer to spend a day working on it. That's detailed elsewhere. Also as I was in the vicinity I changed the speedo sensor which was in the right hand side of the gearbox, facing upwards, meaning it would be a pain to get it off from underneath. This was a straightforward swap when done from above looking down on the gearbox.



Anyway, eventually I got the manifold off, without too much coolant going everywhere. While I had everything off, I had a go at porting the manifold runners out to the gasket line, but I left the head alone. The new gaskets fitted to the head pretty well, but the fit to the manifold was pretty ropey. I also polished up the throttle body and butterfly and ported the body slightly to give a smoother entry. While I was there, in an attempt to fix the idling problem, I cleaned out the idle speed control valve, and fitted new gaskets for the throttle body and ISCV, as well as obviously the manifold-to-head.



I found out that even with the inlet manifold off, the fuel rails and pipes definitely need to be removed or at least moved to be able to get the new silicone inlet pipe in, which is a lot harder than it should be really. In the course of disturbing the fuel rails I had to remove the fuel pressure regulator and when replacing it I accidentally scraped the old O-ring as it went back in. It was only later once I started the engine that I realised it was leaking fuel, and I had to replace the O-ring, which was not much fun seeing as I'd already fitted everything back in place.





After a bit of debate on here and in my own head, I decided I had enough on my plate for the time being without pulling off the rocker cover with the broken bolt. I sealed it up with hermetite sealant and left it at that. It seems OK and there's no other leaks on that rocker cover.

Last job was something I'd been meaning to do for a while which was to replace the factory clutch hose with a stainless steel braided version as sold in the States by SPT. Well I had ordered the Goodridge parts from Demon Tweeks a few weeks earlier, so I made up the 600-03 hose with a 45 degree banjo on one end and a 10x1.00 female fitting with a convex seat on the other. After a few problems bleeding the system out properly the pedal feels great, in fact more positive in action than it's ever been. I used Motul RBF600 brake fluid for the clutch system.



So what have I achieved? Well, the standstill idle seems much more solid, and the high idle when coasting along seems to have come back properly. I had a decent level of vacuum before (around 17 inHg on idle, 22 on overrun) but now my vacuum seems a lot better - 20 inHg at idle and 25 on overrun, so presumably I did have a slight vacuum leak somewhere. The whistling is now gone from the turbo, which must have been caused by the split in the inlet pipe and it all fits up nicely. The alarm now chirps properly when arming and disarming. The speedo needle is performing fine and so far I've not seen any low speed bounce at all.

Most interestingly, the engine sounds a lot healthier and I feel happier giving it the full beans out on the road. The combination of the Green 'Group N' panel filter from TSL, silicone inlet pipe from an ebayer in Hong Kong (Zenaracing), porting and polishing of the throttle body and the ends of the manifold runners and new gaskets all round seems to have really helped the engine pick up nicely. It's mapped by Zen for 1.4 bar on a Power FC with a VF35 and 440cc yellow injectors, and tonight after taking it out on a 4th gear run, above 2500 revs it's making boost as soon as you put your foot down, and hits 1 bar by 3200 rpm, which seems to me to be about 400rpm earlier than it used to. It also used to only overboost by 0.05 bar - e.g. if on the 1.4 bar setting and you floored it, on a cold night it would hit 1.45 before dropping back, and once only I saw a 1.50 overboost. Normally the overboost is in the region of 0.0-0.04 bar. Tonight after a run the peak had hit 1.55 bar with no more than 12 showing on the knock readout.

Obviously this will all need further testing, and I'll probably set it back to 1.2 bar for the time being, because I know it's safe at 1.4. But so far, all seems well, especially the induction mods that appear to prove the well-used saying of 'Many a mickle makes a muckle' - which I first heard on Scoobynet! It looks like this 'muckle' is worth 0.1 bar of boost. Not worth doing the work for the sake of it, but they were all jobs that needed doing while I was there...

 

Good write up there, looks like i will be doing the very same job very soon.

Going to fit spacers and a fuel rail conversion also

 

You have done well. I think I would have left the rocker cover bolt too.

I decided to do the facelift dash swap last weekend, the weather & short daylight hours didn't help much either. I managed to get most of the important bits done so that the car would get me to work on Monday.
I have been finishing the rest today.

Ticky

 

Well I've been working to a deadline too...everything needed to be finished and running today, so that we could do the Christmas visiting to both sets of parents with all the baby stuff (pram, cot etc etc.) in the back. The wife's Yaris won't cope!

Hence I spent yesterday morning driving around every motor factors that was still open (Christmas Eve and a Sunday as well) to try and get hold of an O-ring. And in the end the nearest match for my regulator was in my parts drawer all the time.

There were only a couple of things I would have done as well if I had more time: fit inlet manifold and header tank spacers, and do a better job of porting and polishing. I really needed one of those flexi drill attachments so that I could have got further into the manifold runners, as I couldn't really go much further than a couple of inches in. It seems as if even that little bit I did in matching the ports up helped the turbo spool earlier, even if it wasn't the best polish in the world.

 

Seems a good job done.
Projects is for all 'events' not just high spec stuff! Must admit I had the same feeling when i made my first Thread in that section, and 22B is even more stratopheric.
Look very neat now.

My wife has a Yaris which has been a fab car sinve new in 1999, and has never had the plugs out or the battery off since then, now 55K miles 'young'.

Graham

 

Maybe one of the mods will move it then? I've got to say though, the Yaris was a 2001, and it has never had a single problem. All it needs is a dealer service once a year, and it never misses a beat.

 

looks good, i did the similar to mine not so long back only mine wont idle properly now!!! waiting for new bits to try!

 

Well the idle has now settled back into its naughty old ways, but it's a lot more consistent now and should be easier to track...now, when warmed up it's spot on, perfect. When cold, it hunts up and down. In most cars I'd put that down to a coolant temp sensor or lambda fault. With a Subaru it could be anything. But at least it's a consistent repeatable fault now. Anyone got any ideas?

A few things I'm mulling over:
Changing the idle/water temp correction on the Power FC?
Wiggling the ISCV around to see if that fixes it?
Problem with the ISCV/water pipe interface (electrical/mechanical??)


Checking lambda and coolant temp output voltages?