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What turbo +won't boost


Calq98
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That's definitely a v3 /v4 set up due to the type of tmic [emoji6]

The vac lines between the turbo and actuator ain't standard but that doesn't mean that they're not right for your remapped ecu .

Has it got a boost gauge ?

Couple of things that might be worth a try to see if you can get it to make boost but don't give it full beans or run it for a long time (it's just to try to diagnose)

Remove the dump valve and block the pipe it was in and the vac line that was attached to the top then take it for a test run . This will help to rule out a leaky dump valve being the cause of your lack of boost .

If no different plumb it back in then try this

Take note where the vac lines currently go then remove the vac line from the turbo outlet and plug the vac line you removed (so it doesn't leak)

Remove the vac line from the actuator plug this also

Then run a new vac line directly from actuator to turbo outlet.

This will by pass the boost solinoid and vacuum system and should give you "actuated boost" about 0.5 bar

Also Have a squint at the ecu to see if it's definitely been upgraded as the previous owner might have sold the mappable ecu and fitted a standard one

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Blimey mate u know your stuff on scoobys. Pretty sure it has a boost gauge. I haven't actually driven it on the roads as of yet.. But it was my best mate that owned it and needed rid so I bought it very cheap as I wanted a project. It's still has the ecu in it.. My new intake turned up today so I'm going to try get that fitted tomorrow.and if that does not work I'll try what u have told me.. The little hoses which I guess are the vac hoses that go to turbo and actuator do have a t piece which is the boost controller. And obviously that isn't standard.but I'm hoping to get rid of. Also the dv+ hose I was going to change as its been a budge up job.. With a radiator hose. I do have a turbo 2000 Impreza for spares would bits like boost solenoid and vac hoses be the same if I want to change to eliminate thing. Providing this split intake pipe isn't the problem

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And when u say vac hoses, plug and bypass the solenoid. The turbo outlet and actuator vac do u mean the small hoses where the t piece for controller is? The ones in the pic.. Also would the turbo be standard if it has IHI turbo written on it ? Sorry for all the questions haha

post-4666-0-64060100-1435775870_thumb.jp

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I haven't owned any other turbos than tdo series or garret but I think the v3 sti came with a vf23 turbo (320 hp+) which will have ihi on it as well (maybe check on Google images)

Plugging hoses you undo while test running the engine is Just a precaution as when you run a new vacumm line directly between the turbo and actuator the boost solinoid /vac line system is disconnected but it will suck crap into the system as the ecu will still be operating it

The pinkish block in the middle of the black small dia vacuum lines (as stants said) looked like it was for a boost controller but if it's been mapped they're not normally used cos the mapper sets the boost targets during the remap. Most people dont like to up the boost without adjusting the fueling scale as if it runs lean it will eat itself .

Hence why I asked if you were sure it had a mappable esl daughter board or simtek / alcertek hard ware inside the factory looking ecu case (standard ecus ain't remappable otherwise )

where do the vac lines to and from the pink box go ?

If there's a boost controller is it working /plumbed in ?

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Ryt..I've fitted the intake pipe today.. What a ba*tard to fit with the intake on. Still the same does not boost! Ruled out a leaky dv. Still

The same. It's still idling crap too. There manual

Boost controller is still present in the car. The lines for it are wierd. Got the pick t piece between actuator and turbo. From the t piece in goes into car.. Then there is another hose coming out into a white thing.. Which then goes to the solenoid.. As picture shows

post-4666-0-32477100-1435871096_thumb.jp

post-4666-0-22775200-1435871137_thumb.jp

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Did you try removing the vac line with the pink t piece in ,blocking the t piece either end and then running a new vac line between turbo and actuator?

Also check all other vac lines to make sure they're not perished or split as a leak in the vac line system could cause ropey/ high idle and lack of boost

white bit is normally in the standard vac line set up anyways bud but if you've got vac lines going into the car try to follow them in case it used to be attached to something (boost gauge) that's no longer there leaving a open airway into the inlet manifold (air/vacuum leak)

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I didn't mate but going to give that a go tonight. As I didn't have some

Small enough hose for it.would you know if a turbo Impreza(not Sti) have the same vac setup? Was thinking of swapping solenoid etc over.. And putting the vac setup back to standard without boost controller.

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If the spare scoob is a late 96 to early 98 (v3 or v4) they're very similar with probably only a difference in the size of the restrictor pill .

Only problem is IF it's been mapped with the current vac line set up as it is changing it back to standard might not work unless you fit a standard v3 sti ecu . You can't fit a standard uk or wrx ecu as the turbo / injector size is different from the sti's .

So by passing the posibily faulty boost controller with a new vac line might be the best thing to try first

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Bypassed the controller.. With a simple straight pipe.. And still no boost. Looked at the spare scooby and the vac setup is slightly different..I did find a split vac hose replaced that but idling is still hunting. Up and down on revs. On the intake pipe just before turbo on the right is a hose outlet that goes onto a metal pipe which is behind the inlet..well that is blocked off and I guess that loops round to right side outlet on inter cooler normally? Is it worth me trying the solenoid off spare scooby ?

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I've been playing around with the car.. Still idling Crap.. Disconnected the maf while it was running and didn't change it. Still idling crap, I take it the maf is knackered ?

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Yeah it's supposed to stall, do you have a multi meter? More accurate diagnosis would be to test the voltage.

What colour sticker is on the maf body ?

Sent from my SM-G850F using Tapatalk

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Yeah it contributes to rubbish fueling, may be so bad it's nocking it into safe mode,

Least the orange label ones are relatively cheap to replace

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Possibly not, if yours is running an aftermarket ecu ?

Might explain the lack of boost, how many rpm are you able to pull through the gears ?

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Yeah it's been mapped.it will Rev right up with no splutters. As I previously said I bypassed all the solenoid and ran a hose from turbo to actuator and I didn't even have actuated boost. Which is making me think the actuator is knackered. Aswell as maf.

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If it's fitted with a esl daughter board or simtek / alcertek software these ecus can be remapped to run mafles , so unplugging it might not make a difference if the maf has been "mapped out" .

Unless there's a few faults giving varied symptoms I'm a bit stumped as I can't think of one problem that would give you lumpy idle but rev up fine with no boost that wouldn't give you a code on the ecu

Check over all the vac lines for splits and leaks if certain ones look suspect or hard to get to you can spray a little brake cleaner around them when the engines running and the idle will rise if the cleaner gets sucked in if there's a leak .

Do be careful as brake cleaner is flammable and if you spray to much at once or spray it near exhaust/headers it might ignite

Try checking the spark plugs as these are normally a good indication as to how a car is running .If they're in good nick(no cracks in the porcelain ect) give them a clean up and gap them to 0.7

As if one cylinder isn't firing right you'll get lumpy idle ,you can normally rev up without spluttering and possibly no boost but it would sound like it's "missing"

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