I hookd up my boost gauge to the map sensor sensor on the wall by the intake elbow. This is a 93 rx7 we are talking about with no mods except for a catback exhaust. Boost creeping up to 15 psi and not even under wot. Is mmy gauge reading it in accurately from the map sensor or am i actualy getting a whole bunch of boost creep from maybe a sticky wastegate? Thanx for any suggestions and advice =)

 

If it has the stock ecu it should either hit fuel cut or blow before 15psi. what does the gauge read when car is off? maybe its a gauge that reads absolute pressure, like it would show 1 atm at sea level when the car is off.

 

Your average automotive gauge is extremely unlikely to read absolute pressure. Almost by definition it will read gauge pressure.

If the gauge is an Autometer, it is very likely inaccurate - but most likely not inaccurate enough to indicate 15 psi for a real 10 psi. In other words, stop driving the car until you install a proper boost control unit.

 

k but still need to know if hooking up to the map sensor instead of hooking it up near the intake manifold makes any difference? i mounted my gauge where the factory tweeter is so it made sense to use the map sensor. Would hooking up by the intake manifold give me a better or more accurate reading? I was readign through some guides on fd3s.net and not sure exactly where but around the intake manifold was where it was hooked up to.

 

You will get almost the same reading from both.

 

Have you tried to hook it up some where else and see if you get a better reading?

 

don't t it into the map sensor line anyways, that line should be used for the map sensor and ONLY the map sensor, not like vacuum hose is expensive.

Any chance you have a PFC and commander?

 

so... if you plugged it into your map line/sensor what did you do with your mao sensor? unplugged it? bad idea...

use the nipples on the plenum to get a better reading.

 

He T it it in the map sensor. Plug it where the extra nipple is at on the uim.

 

The boost can surpass fuel cut levels in lower gears without fuel cut due to a slow response from the ECU. I would stop driving it first off.

The first thing i would think to check is that the wastegate and precontrol actuator hoses/lines are intact. You also need to check the hoses/lines up to the WG and PC solenoids if you're going that route of troubleshooting. And the solenoids themselves for being stuck open.

the amount and quickness of it's overboosting would make me think the WG and precontrol are not seeing any pressure from the compressor housing at all.

Also remember, the precontrol also controls boost, but only before transition. PC = pre transition. WG = post transition.

If the lines are straight and you have verified all the boost control system is functional then double check the reading with another gauge.

 

wow guys great help. havent got around to cheking any of these yet. But will do everything then post a solution if it works out for me jus in case it helps some one

 

if you do have a pfc and commander, make sure your map sensor is plugged in and working properly and then check on the commander screen what it shows you, just another way to verify