Grey Import

I've had a running issue with my 97 WRX JDM since I have owned it. I've been on here asking questions but unfortunalty nothing has sorted it. It runs a bit lumpy when cold, kind of hesitates.

I noticed the other day that the recirc dv fitted to it had an incorrect size reducer pipe on it which had been bodged with a bit of extra hose to make it fit. So I measured the diameter of them and ordered the correct sized Samco reducer hose. At the same time I decided to replace all the vacuum hoses as they looked very tired and were very brittle. So I replaced them all with ID4mm Samco Silicone. I'm pretty sure it all went back together correctly as I replaced one hose at a time.

I got it all back together tonight and took it for a drive. The car use to hit 1.3BAR on the boost gauge, it now only goes to 0.6 and the car seems really flat. I noticed when I first pulled off there was a strange squeeky noise coming from the near side of the engine bay? I'm guessing now but could my dumpvalve have not operated properly before and now it is opening fully due to having the correct pipe fitting to it? How do you know if the car is over boosting or underboosting? Or is it a case of getting it set up on a rolling road?

Thanks in advance, Jamie

jaytc2003

iTrader: (1)

does the squeeky noise only apear on boost? I have a similar problem after fitting a fmic. I have a feeling it is a boost // air leak. Your fuel economy may go through the roof as well!! I have some better quality clamps to fit this weekend so wl let you know how I get on.

Jolly Green Monster

iTrader: (4)

there is a restrictor in the short pipe between the compressor cover nipple and the T piece in the pipe work.. you need to refit it in the new pipe work.
99% sure this is the boost issue it you have fitted the pipes correctly..
If you post a pic of the vac lines on the turbo etc it is easy to tell you if they are correct also.

Simon

Grey Import

when you say compressor is that the plastic thing that looks like a one way valve? I have refitted this in the same orientation. I'll get some pics taken tonight after checking all my hose connection for leaks.

Jolly Green Monster

iTrader: (4)

no.. the restrictor is in one of the pipes from the T piece, it is metal.

it is in the shortest pipe..

Simon

Grey Import

ok a few pics not sure if you can pick anything out. One of the hoses was slightly loose so I put a zip tie around it one on top of the inlet manifold. It still has the problem tho. If you need any better/different pics I can take some more. Thanks for your help. Took one of my new reducer hose on the dump valve I could put the old one back on see if it makes any difference.

Jamie

Grey Import

Does anyone have any more ideas?

Thanks Jamie

Jolly Green Monster

iTrader: (4)

you need to find the restrictor within the original pipework and fit it to the new

jim litten

TBH the non-reinforced silicone hose that you've used for the boost control pipework isn't very good at doing that job as it is very soft, and can stretch/expand easily when cold, and once it gets hot around the trubo area becomes very soft, and under vaccum conditions can collapse, if you compare it to the stuff you've just taken off you'll see what I mean, and for applications where you want instant response (boost control) soft hose isn't ideal.

Grey Import

There wasn't a restrictor in the original hoses. I replaced them one at a time measuring the length so they were exactly the same and so I didn't connect them up the wrong way around? Do you have a picture of your restrictor on your car so I can see what it looks like?

Jim I think you are right the hoses are very soft suprisingly so. The reason why I replaced them was because they were very hard and had started to perish at the ends so I thought the Samco Vacuum tubing was designed for this job.

The problem I have now is I chucked the old hoses out last week. Does anyone know where I can get some stronger hose with ID 4mm so I can see if this is the problem?!

Thanks for all the help very useful.

cheers Jamie

jim litten

I use small bore fuel hose, its meant for pressure applications and because its reinforced it'll not collapse, if your after the bling effect then unfortunately it only comes in black can be got from any motor factors and Halfrauds if you're really deperate.

jim litten

Can you take a closer pic of the connections at the turbo as it's not very clear, your pics make it look like you've connected the manifold sensor line to the compressor tee piece.

Grey Import

Hope these pics are better its hard to get it all in a close shot!

jim litten

That's clearer, as Simon said the hose nearest the arrow marked turbo (on compressor cover) needs to have a restrictor in there as without it you're only going to make actuator pressure (0.5bar).

gazza19800sti1

restrictor all the way its IN the original pipe , feels like a small lump hard to find if your not looking for it . ( i did this once) oopps

RICK1702

Hi, i did the same thing with my 96 wagon, the restrictor is in the short piece of pipe to the right of the turbo, the mechanic (stan palmer subaru tained) sorted my restrictor by using a bleed valve which he set to the correct boost pressure, apparently if you try to buy the restrictor you will have problems as their are lots of different sized ones depending on the model etc, if you put the wrong one in then you could get overboost problems causing engine damage, my bleed valve was set correctly and the car is running perfect, the bleed valve was under £30 and is still rigged up to the boost solenoid, it works by screwing the screw to the desired boost (to the same bore as the original restrictor), hope this helps

Grey Import

I'm glad its not just me who has done this! I'm pretty sure I still have one of the little hoses at home somewhere so fingers crossed this one has the restrictor in it! The hoses were pretty bad though so if the hose does have a leak is the best bet to get one of the boost bleed valves then. Would any half descent garage that work on subarus know about this restrictor? Or is it really a specialist thing?

Thanks again for all the help. cheers Jamie

Grey Import

Just found the small piece of hose and guess what it doesn't have the restictor in it

I guess I need to try find a boost bleed valve or a 1997 WRX that getting broken!

bruce

iTrader: (5)

I made one out of some 6mm brass bar, just drilled a 1.2mm hole through it. Got the bar from B&Q and a precision drill from a friend, but I guess you can get them easily enough.

Grey Import

Hi Bruce, How did you know that the hole needed was 1.2mm? That seems like a pretty good solution to me may have to give it a go

bruce

iTrader: (5)

Just general knowledge picked up of Scoobynet and 22b.com.

Hope it helps.

Grey Import

Managed to get a restrictor from Bucks Subaru thanks guys. Just fitted it now. The car now boosts to 0.9BAR it use to go to 1.2 on the boost gauge. But is is pulling very strong so it can't be very far off. Just thinking maybe I will change the hoses to normal rubber ones as the silicone ones do tend to get very limp when they are hot so that might be a contributing factor.
The car seems to be running spot on so maybe my running issues were connected to the dodgy reducer pipe that was fitted to my Dump Valve. Fingers crossed it keeps performing. Thanks for all the useful help people. In future I may ask questions before changing bits on my car