323 GT boost light question

[TRRC]

What does the little green "turbo" light on the upper part of the dash indicate? It lights up at around 2700 or so RPM when I'm giving it the beans and today after some spirited driving it started blinking for awhile. After letting the car idle for a few minutes I turned it off and when I started it back up later it seemed fine, indicator was off. What does it men?

[trailrider098]

thats a sensor that just tells u the turbo is making boost. dosent do anything but was a cool little feature in the 80's


EDIT: Was this a serious question?

[BFMRGTX]

I also think it blinks when in an overboost condition.

If it was a serious question, I hope you have a FSM on hand.

[shorestiva]

Doesn't it beep too when it detects overboost?

[BFMRGTX]

http://autos.groups.yahoo.com/group/323gtx/message/23747

http://autos.groups.yahoo.com/group/323gtx/message/16299

^^^^ there are more topics on it, but this is the gist of it. Find and disconnect the overboost sensor on the firewall. The vacuum line off the top of the intake plenum (passengers side) will lead you to it. unplug the electrical connector, use the now vacant vacuum nipple on the plenum for a boost gauge.

Are you running a safe amount of fuel? Got a larger fuel pump installed? Have a AFR gauge? EGT gauge? Any gauges at all?

[TRRC]

http://autos.groups.yahoo.com/group/.../message/23747

http://autos.groups.yahoo.com/group/323gtx/message/16299

^^^^ there are more topics on it, but this is the gist of it. Find and disconnect the overboost sensor on the firewall. The vacuum line off the top of the intake plenum (passengers side) will lead you to it. unplug the electrical connector, use the now vacant vacuum nipple on the plenum for a boost gauge.

Are you running a safe amount of fuel? Got a larger fuel pump installed? Have a AFR gauge? EGT gauge? Any gauges at all?

Right now everything mechanically is stock. The fuel pump is new, but I really have no idea what kind of shape the injectors are in. The engine idles and revs smoothly, the check engine light is off, I have no smoke out of the exhaust. I don't have any afr or egt or boost gauge but I will definitely install a boost gauge now that you have explained it for me.

So the light blinks in "overboost" or buzzes? I definitely get a buzzer around 6k rpm when driving hard. Is overboosting a problem with the wastegate or assembly, where it isn't holding the correct boost level?

[shorestiva]

If your exhaust flows better than stock that can cause overboost. The wastegates on stock turbos are way too small.

[TRRC]

So it allows the turbo to develop too much boost? Is that why it kills power at 4750 rpm under full throttle acceleration?

[BFMRGTX]

If your exhaust flows better than stock that can cause overboost. The wastegates on stock turbos are way too small.

Yep, that was going to be my next question.
You'll need to put a boost gauge on and monitor what it's doing. I recently had boost spike issues after R&R'ing the engine and tranny; found out that the vacuum line off the hybrid turbo was disconnected from the inlet to the Greddy boost controller stepper motor. I was busy looking at the AFR gauge to determine if I had a boost/vacuum leak somewhere when I caught the movement of the boost gauge out of the corner of my eye.

Are you running (probably yes) a larger than stock exhaust? What about the downpipe? Stock? Turbo? Got the vacuum line on and it's in good condition? Only other thing I can think of would be a sticky actuator.

[TRRC]

Umm... does no exhaust at all count? I don't even have the downpipe on right now. I suppose without an exhaust it will hard to diagnose any other problem or issue so that's what i need to start with.

Is the issue a lack of backpressure?

I do want to run a 2.5" pipe diameter pipe with no cat and I have a pacesetter dual tip muffler from an old turbo supra to put on the end.

[BFMRGTX]

Protip: You might want to mention things like: "No exhaust" or: "It doesn't have an engine" right off the bat...

[shorestiva]

Yeah.... thats probly causing it. Mine overboosts with 2.5in dp back exhaust.

[TRRC]

This is only my 2nd turbo car. my first one was a supra that I only drove twice then sold, so im kinda newb-ish to boost spikes and what-not.

[corby_baby]

Protip: You might want to mention things like: "No exhaust" or: "It doesn't have an engine" right off the bat...

i lol'ed

[BGfamiglia]

anybody know what wire controls the boost indicator light in an 88 gtx? i have installed a bpt in my bf gtx and i would like to reconnect that indicator light if possible, just for fun. has anybody done this before?