1989 Toyota GT4 Celica ST165

Was running fine. Suddenly started over heating so diagnosed as blown head gasket. had head plained and
new top end gasket set fitted and now cant seem to get to run propperly no idea whats wrong with it.
Just doesnt seem to boost can hear turbo and everything seems in order ie cam timing and ignition timing.
Still Drives just no power.

Is this limp mode?, does anybody have any ideas how to fix as I'd like to be able to help this guy?

the computer will only be in limp mode if the check engine light is on.

Limp mode usually is a term for automatic transmission problems (or Fail safe mode). Transmission stays in 2nd gear and won't shift. Maybe a bunch of water and oil and crap down the exhaust causing a plugged cat ???

JDM's don't usually have cats, any ideas what the problem could be?

ill go with my standard diagnostic....some sort of electronic wizardry. o2 sensor?

it's either timing or a horrid boost leak. IF there is no check engine light

is it throwing any codes?

check compression also. maybe rings are shot

I'll find out

Highly doubtfull the rings etc died while the head was off, more like something not connected/lined up
or sealed properly?

I think my other All-trac is like that also, but now it doesn't even start up.... the odd thing is when you have a gt-s ecu in it it does start up but not smooth and this just happened after the new head was put back on.

don't use the ge ecu phantom.

Somebody suggested a problem with the knock sensor?

if the knock sensor was bad or the wiring was bad the ecu would throw a code.

Would explain it not revving?

Owner says check light is intermittent but doesn't know how to read codes

have to get those codes.
trouble revving is typically a mechanical timing issue if its not misfire related

owner now says no codes showing, no leaks, not revving
I might be able to buy the whole damn thing this week, so still looking for an answer

Looking at the BGB there's a water sensor connected to the IC ECU and pump.
The IC ECU is connected to the ECU, could it be water/sensor related?

Sounds plausible, if the ECU thinks the IC pump isn't working it would probably kill the power to prevent any damage to the engine/turbo.

Test drove it today to see why it won't rev
Starts fine, idles rock steady - boost gauge reads -3psi at idle
Pulls away fine and makes +8psi boost very quickly (2000-3000rpm), then the boost needle drops back to zero
and stars climbing again, this happens every time the boost reaches 8psi.

Original fault as described by previous owner:
Was running fine. Suddenly started over heating so diagnosed as blown head gasket.
Had head plained and new top end gasket set fitted and now cant seem to get to run properly no idea whats wrong with it.
Just doesnt seem to boost can hear turbo and everything seems in order ie cam timing and ignition timing.
Still Drives just no power.

My noobness is telling me that the wastegate is up to no good?
Is it opening too early?
Can I adjust it?

I looked at the BGB and there's no mention of adjusting, every thread I follow says "replace turbo unit"

There's a ST215 manifold and turbo for sale, how difficult is it to adapt?

you don't want a 215 turbo.

Problem was found to be a crappy boost gauge install
The pipe to the manifold was holding but leaking at 8psi, now runs -20 at idle and +15psi
which is weird, aren't they supposed to cut at 12psi?

ST215 manifold + newish turbo = $50, can't I use the manifold or something?