Hi,
 
I've got a 94 MR2 turbo and have run into some power issues :(. Basically I had a track day a few weeks back at Phillip Island and one of the silicone joiners split, dropping the power hugely. I did some patching at the track with tape but it didn't hold well and I ran the whole day with boost leaking and I could only get to about 6psi max boost.
I replaced the split boost hose today and went for a drive but the car is dropping power hugely. It feels as if it missfires around 3000-4500rpm. It definately has  stuter when boost comes on.  Also it doesn't pull anywhere near as hard as it used to. The other odd thing is that on low boost its only making around 8psi when the boost controller is set to 10psi. However if i switch to high boost it will make 11psi boost when the controller is set to 14psi. Nothing on the boost control has been changed, it just feels slow and under powered. No smoke out the back and I pulled the intake pipe off the check the turbo. The compresor wheel spins freely and has about 1mm of play. Even at idle the compresor wheel is spinning by itself so I dont think the turbo is gone. I can't see any boost leaks from joiners. Any ideas what it could be? Has anyone had a similar issue?
 
 

After some research I think I know what the issue will be. I reckon the ecu has gone into low boost/safe mode, so its retarded the ignition timing and limiting boost to what it think is 7psi, keeping in mind that the electronic boost control is bleeded boost to trick it. That will explain around the 3psi boost drop in both settings and the missfire/stutters on acceleration. I'll do a ECU rest and see how it goes. Driving a full track day and the drive back from PI with boost leaking must have triggered the mode.

Update......I reset the ecu and the power got a bit better but it is still in safe mode. Boost is always around 3psi less then what it should be and the car moves better at partcial thottle then full throttle. Only option to get a toyota diagnostic on it and see if a sensors out. Anyone else have this happen to them? If s, do you know what the cause was?

Have you checked for error codes?

Cheers

Hi,
 
Yeah I did an error code check by bridging the port TE1 and E1. The check engine light flashed steady so I don't believe any sensors are registering a fault.

Check your plugs, running all day with boost leak might have fouled them.

Hi,
 
I've read quiet a few posts on the net about people having issues based on ignition problems in these. Especially leads. I ran a multi meter to test resistance and thye seem to all pass current through, also the plugs are black (dry/black) but thats normal on a turbo MR2 right? Plugs are iridiums. I wa thining of just changing, cap/rotor/leads and plugs doing another ecu reset and seeing if fixed. Not sure if I'm chasing the right thing though or just deperately hoping?
My other thought was maybe a leak in the intake manifold, maybe the gasket somwhere? Could try the water test and see?

Could be ignition related. Do you know when the cap/rotor/leads were changed last?
Take the dizzy cap off and have a look?
 
Are all your other IC hose connections in good shape? Maybe replace them and the clamps if they are still the stock ones.

Hey,
 
Yeah I would have gone straight for the ignition but I can't think of a reason why the boost would be effected. The boost seems to be down 3psi on what it should be when on low boost and again 3psi less on high boost. The fact that it gets 7psi or so when it should be 10 and 12psi when it should be 15 is odd. If it was a piping leak, really the wastegate shouldn't open at all and running high boost shouldn't have any kind of increase.
I should mention I have silicone joiners, metal piping and heavy duty clamps. I aqlso have a mines chip in the ecu, so I wonder if low boost could be set but no engine light flashing because of the chip?

Just to confirm you have disabled the stock ecu boost control solenoid when you installed the boost controller? (Plugging the second port on the wastegate)
if you haven't done this than you are fighting with the ecu to control boost. It is trying lower it whilst you are trying to raise it.