Engine Light

[YangS]

Hey;
I have a problem with my 89 supra turbo. Every time I boost up to 5 psi the engine light comes on and holds back the cars boost.

Does anyone know what's the problem? Why does the engine light come on everytime I revved up to 4k rpm or boost 5 psi?

I changed the O2 sensor and the cat but nothing has changed ; still does the same problem.

[Jeeves]

Have you pulled codes yet? That'll tell you why the light is coming on.

[Zach Ayres]

My 89 turbo had that same problem sometime ago. It turned out all it was, was one of the lower intercooler pipes. The pipe had a huge crack in it. The check engine light would come on when the turbo boosted a little or at high rpm. So I replaced the pipe, it was like $100 at the toyota dealership. Hopefully this can help you.

[Tosh]

Yep, you're hitting fuel cut. code 52 or whatever it is. You have a massive air leak somewhere in your intake system. take it all apart (accodian hose and intercooler piping) and check for cracks tears or brittle hoses. ensure all connections are snug, most common ones are the ones on the accodian hose and the one at the throttle body. Check all your vacume hoses (skinny ones) ensuring they're all connected and in good condition. Also check the thicker rubber hoses for the pcv etc... that come off the accodian hose.
If you find that your intercooler hoses are garbage (which is bound to happen on a 15 yr old car), don't bother going to toyota to replace them. Try this out instead:
http://www.jblmk3.com/id1_custom_jbl...oler_pipes.htm

[YangS]

Hey;
Thanks, I guess that seems to fix the problem. It was one of my vacume hoses; looks like it was burnt from the engine having a hole. And just recently replaced it, thank you.