Stuck in low boost mode rev1 turbo

[wilko1985]

Hi guys

Need some advice, I believe my rev 1 turbo is stuck in low boost mode .

So far I've changed the plugs, dizzy cap and rotar arm but still no success.

Previous work on the car in the year was a walbro 255 (hopefully genuine), new ht leads, decat, and IC

I've tried checking for error codes, but for whatever reason nothing is displaying. Not sure if the connectors are broke on this.

My car has a manual boost valve and it looks as if the tvsv valves have been cut and plugged up.

Anybody got any ideas? Without being able to check for error codes I haven't got a clue....

Cheers
Chris

[Mike N]

If you have a basically std spec engine but have fitted a walbro 255 pump, the engine will run way too rich and kill the power and bore wash the engine.

I would suggest you either run a stand alone ecu to controll the extra fueling and do all the tuning stuff or return pump to std and then start looking for running issues.

Since you have the manual boost valve, check for air leaks in the pipe runs. The TSV should be blocked off if you run more than std boost.

As with any turbocharged engine check for air leaks in the pipework system and intercooler from turbo to inlet by blocking off and pressurising system with air.

[Al-sw20]

Open the boost valve. I assume you have a boost gauge that shows you only running 7psi?

Disabling the t/vsv puts it in low boost mode so you can then wind more boost in it.

[2mad]

Open the boost valve. I assume you have a boost gauge that shows you only running 7psi?

Disabling the t/vsv puts it in low boost mode so you can then wind more boost in it.

Yep .. you need to look at the boost controller bud


Mbc's can cease up and bleed valves can clog

[jimGTS]

You'll always be stuck in low boost mode with the tvsv disabled.

That is the point of a boost controller to then raise the boost.

[2mad]

You'll always be stuck in low boost mode with the tvsv disabled.

That is the point of a boost controller to then raise the boost.

He says he has a boost controller Jim .. mabe its faulty

[wilko1985]

Cheers guys

I had the boost tested last week ano it's coming out about 10-12 psi on their gauges. However, even though they said that's the pressure (from the manual boost gauge screw pipe work) the power on acceleration is still hugely down.

I might be looking in the wrong area... but it's always the same power as when it's cold. This has only started happening the past few weeks really. Prior to that it was absolutely fine. Then it went to boost as normal (when warm) and it dipped hugely.

[2mad]

Hi mate what revision mr2 do you have .. and what form of boost control are you using .

[wilko1985]

Hi mate what revision mr2 do you have .. and what form of boost control are you using .

Hi mate, it's a 1990 rev 1. My knowledge is shocking to be honest, but looking at what has been installed it's got a brass valve which can be used to manually adjust the boost. Without putting a metre on it there's no way of knowing myself, but the guy I take it too said he pressure tested and turned it up to 12 psi..... it definitely does not feel like that . Ha. Maybe through the valve it's doing 12psi...

I checked last night whether it might be something to do with the tvsv but after finding it that seems to have been blocked off and capped up. The guy who owned it before me was a btcc engineer so seems to have made a very tidy job of it.

My dad did decide to hose the engine down noto so long ago.... I'm thinking he may have soaked and ruined an electrical component somewhere?

[2mad]

Hi mate what revision mr2 do you have .. and what form of boost control are you using .

Hi mate, it's a 1990 rev 1. My knowledge is shocking to be honest, but looking at what has been installed it's got a brass valve which can be used to manually adjust the boost. Without putting a metre on it there's no way of knowing myself, but the guy I take it too said he pressure tested and turned it up to 12 psi..... it definitely does not feel like that . Ha. Maybe through the valve it's doing 12psi...

I checked last night whether it might be something to do with the tvsv but after finding it that seems to have been blocked off and capped up. The guy who owned it before me was a btcc engineer so seems to have made a very tidy job of it.

My dad did decide to hose the engine down noto so long ago.... I'm thinking he may have soaked and ruined an electrical component somewhere?

Buying a boost gauge will help .. i would not advise turning it up till you have one ... if you have a fcd 14psi is a good place to be on a rev1 .


If it was electrical the engine electrical light would light up on your dash .

[wilko1985]

Yea I'm trying to decide how muche more money I want to sink into it. I suppose I've gone this far.... ha

Ah ok I see. Would a possibly faulty sensor bring up a light? I'd check for an error code but for some reason it's not working any more.

[2mad]

I would bet money its just your boost controller at fault .. BUT .. 12psi is quite healthy ... maybe it just needs adjusting

[thomp1983]

Does the engine light come on when you turn the key to the second click before starting?

[wilko1985]

I hope so, the rest of the car is tip top. Once this is done I can finally get it on the track.

[wilko1985]

Does the engine light come on when you turn the key to the second click before starting?

I'm not actually sure but I'll double check tonight when I get home

[2mad]

Does the engine light come on when you turn the key to the second click before starting?

Very good question .. bulbs can pop

[wilko1985]

Does the engine light come on when you turn the key to the second click before starting?

Very good question .. bulbs can pop

Success, I managed to get the engine management light to report.... does this mean anything to anyone? There's no break just a continuous on off

youtu.be/TUiT4hfws98

PS I broke up the link as it won't let me post them fully.

[thomp1983]

A constant blinking means there's no fault code. The only free thing you can do is fully check all boost and vacuum lines for splits

[2mad]

A constant blinking means there's no fault code. The only free thing you can do is fully check all boost and vacuum lines for splits

Yes .. this should defiantly be on your list of things to do .. check the bov too.

[masterbateson]

If you have a basically std spec engine but have fitted a walbro 255 pump, the engine will run way too rich and kill the power and bore wash the engine.

I would suggest you either run a stand alone ecu to controll the extra fueling and do all the tuning stuff or return pump to std and then start looking for running issues.

Is this right???? I wouldnt have thought fitting a better rated pump would have any effect Doesnt the car have a pressure regulator on it? and doesnt unused just go back in the tank? and finally dont the injectors regulate how much fuel is supplied per stroke?