oblio

so i am experiencing moderate detonation pretty much all the time under boost.
my car's setup is pretty stock, it is an emissions free, straight piped 87 tII.
i just drove the car from albuquerque (elev. 5500 ft.) to WVa (elevation ~2000 ft?), spent a few months there, and came back.
so heres where the problems begin.
my boost guage doesnt really register any boost when i give it throttle. i can hear the turbo spooling, i can feel the boost, but the guage never registers... more than like 10 mmhg (25% of the stock boost guage). when i hook up a mechanical guage, it says that i make 9 lbs before the wastegate opens.
i have tried 2 other baro. pressure sensors, and it still shows the same levels of boost, i also changed the 02 sensor recently. could the ecu not be sensing the boost levels that the car is getting and letting it lean out? i have an rtek 1.7 chipped ecu, but i dont have it installed because i dont have the injectors. should i get the 720cc secondaries and install them, presuming that it is a problem in my ECU?
i also have another strange problem:
also on teh return trip, my car overheated a little (about halfway up the stock guage). i would kick off the ac, let er cool down, then AC it up again
since i have gotten back to ABQ, the car has begun to run WAAY too cold. the stock guage never gets more than 3 or 4 needle widths above the Cold line. i replaced the thermostat, no changes. inspected the harness for the coolent thermo sender etc... everything is connected. now - i know that nobody should complain about having a car that runs too cold - but it makes my idle funky when it wont come up to temp. even after about 20 mins of driving, it will idle at like 750 rpm, then chug down to like 500 like its gonna die, then run at like 1000 for like 5 seconds... then back to 750... idle climbing and dropping like an indy car driver at the starting line. could this idle be caused by poor tps adjustment?

i appreciate you spending the time to read this narrative... i hope you can help me...

GTU_FAN

I dunno if god himself could help you...

GTU_FAN

^and by that I mean that I cant help you sorry.

GTU_FAN

^why did I take the time to say anything if it wasn't going to be helpful?

GTU_FAN

^that's a good question... I dunno. I'm tired. I wish I could help but I haven't learned much about turbo's yet.

Apathy

I would go with the rTek and the new injectors. Get a A/F gauge so you can see if you are leaning out.

GTU_Fan, are you trying to get your post count up?

turbine

iTrader: (1)

If your T stat is functioning (not stuck open) then you are reaching operating temperature. The gauge in the cluster has nothing to do with what the ecu will see, it has its own sensor. Your gauge or sender may be off.
You should take your cars temperature with a temp gun. Or automotive thermometer.
Most likely something else is affecting your idle and the other problems you are having

classicauto

iTrader: (3)

If your setup was detonating the engine an you've been driving and boosting for that long, your thread title would read "where do I buy a rebuild kit and why did my motor blow up?"

arghx

iTrader: (3)

uhh wait

do you have a fuel cut defender? How do you know you aren't hitting fuel cut?

oblio

no FCD but for some reason, i have never hit the fuel cut...
in response to classicauto - i have 1 piece apex seals, and still have compression numbers in the 90's (on my reg. gague), i dont know why my motor hasnt lost compression yet (its 40k mi on a rebuld)
the thermostat is not stuck open, at least, i dont think so since the "problem" didnt resolve itself with a new thermostat. unless the Tstat i bought got stuck open the first time i started the car.

so - turbine - where is the sender that sends the coolant temp. to the ECU? is it the one that is just below the Thermostat, that connects with a green 2 pin connector?
i was going to check the coolent temp -but couldnt find my infra-red gun...

classicauto

iTrader: (3)

1/2 way up the stock gauge is nothing.

Overheating can be caused by many things (many of which CAN BE FOUND IN THE FAQ)

Do you have:

A belly pan?
A good rad with a clear core?
A functioning OEM thermostat?
A functioning clutch fan or comparable E-fan with a shroud covering the whole rad?
Two belts turning the water pump?

oblio

i have all those things classicauto, but my problem is not overheating, its UNDERHEATING.
im mostly concerned about my boost gague not registering the boost levels that i am getting...
if i understand it right, the Barometric Pressure Sensor is reading manifold vacuum / boost, which sends a signal to the ecu telling it whether or not you are in vacuum or boost. the ecu then gives an electronic signal to the stock boost gague, which tells Me how much im boosting.
my manual gague tells me 9lbs, the stock gague, 10mmhg.... big discrepency. is that starving me of fuel?
And, if i have replaced the baro. press. .sens. with no change in observed boost levels (on stock meter), is that a problem with my Ecu?

turbo2ltr

iTrader: (1)

The Baro sensor reads Barometric (atmospheric) pressure, not manifold pressure. The MAP sensor (manifold absolute pressure) is the one that reads boost and controls your dash boost gauge.

oblio

why is the unit that says "barometric pressure sensor" connected to the manifold via a vacuum line?

SaabGuy

The pressure sensor in front of the passenger side shock tower measures boost and registers this on the stock boost guage as well as feeds the ecu.

AHHHH Where to start.. OK, Start by taking your intercooler off, then all intake hoses larger than 1/2 inch in diameter. Check them all, making sure there are no cracks causing intake leaks. Pressure test everything you can. Varify the AFM is installed securly and level. Short of intake leaks, you can do TPS, mixture, and tuneups. All this should solve your idle problems unless your engine is blown.

Next, if you are hitting 9psi, you are hitting fuel cut without a FCD. Stop doing that its no good! Get a FCD, and then varify that your stock boost guage is comming up to like 2/3-3/4 height *** THIS IS VERY IMPORTANT as anything less and your ecu might not be retarding ignition timing enough. Both cases will give you a blown motor.

Next, if your guages arent rising high enough, try tilting your head to the left. There ya go!

zbrown

sounds like issues with the Pressure sensor....

never saw a TII dash, does the stock gauge show Vac or only boost? If it shows vac does the guage work properly in the vac area?

I would troubleshoot the pressure sensor and circuit

sounds like the ecu is seeing 0 psi even when you actually have positive pressure, and you are mistaking the detonation for lean misfire as the ecu is not supplying near the fuel it needs too

SaabGuy

Contrary, zbrown.. The stock ecu supplies fuel primarily by the AFM and other correctional sensors like water and air temp. Also the stock boost guage barely measures vacumm... in fact, the guage itself is a steamy pie of poo. I only ever used it to varify signal from the sensor to the ecu; beyond that its pretty much a useless guage.

The boost sensor doesnt change A/F much except in the way of ignition timing advancement.

Just for looks you'll often see a high boost rx7s with stock ecus blow motors even when fuel is adequate; most likely due to using a FCD which fakes out the ecu causing not enough timing retardation = blown motor.

Its a lose-lose situation when using a FCD. You'll blow up if you dont use one, OR your blow up if you use one with too much boost. Best save your money for an aftermarket ecu, but who all can do that at $1000 a clip.

zbrown

Its been a long time since i have messed with a stock ECU

Its all a haltech in my head now..... sorry, just threw out the first thought i had

you are right