multiple problems

[RonPence]

i have a 90 7mge 5-speed and the car has not run right since i purchased it.
i noticed my check engine light was burnt out so i took the dash apart and realized someone had removed it. well i replaced the bulb and checked for codes i got 21, 51, and 52. the car seems to be down on power and idles around 1,400 rpm! i looked up the codes but wanted an opinion on where to begin. if the tps is bad will the one off my 87 turbo work? i dont have that car here and i am not surre if they are the same. the car dosent want to run at all when it cold it just spits and sputters but when it comes FULLY up to temp it run out smooth but misses slightly at an idle.

 

[silvergsx623]

for the code 51, check out JJ's post

http://www.supramania.com/forums/showthread.php?t=46793

My code 51 ended up being an adjustment screw on the throttle bracket.

 

[SevenMKIII]

i noticed my check engine light was burnt out so i took the dash apart and realized someone had removed it.

What some people will do to "fix" a problem...:3d_frown: But you're smarter than that!

I have a pre and post 89 TPS if you need one. Try adjusting yours first, could just be out of spec. If it's dead shoot me a PM.

 

[shaeff]

21
Oxygen Sensor Signal
Diagnosis
Detection of oxygen sensor deterioration.
Trouble Area
Oxygen sensor circuit
Oxygen sensor
ECU

check the wires on your o2 sensor. sometimes they get brittle and break. if the o2 sensor is bad, replace it.

51 Switch Signal
Diagnosis
No "IDL" signal, "NSW" signal or "A/C" signal to ECU, during diagnosis check.
Trouble Area
A/C switch circuit
A/C switch
A/C amplifier
Throttle position sensor circuit
Throttle position sensor
ECU

check to make sure the linkage isn't stuck on the throttlebody. if it is, fix it. if you still idle high, check the specs on the TPS. here's how: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=100

52 Knock Sensor Signal
Diagnosis
Open or short circuit in knock sensor signal.
Trouble Area
Knock sensor circuit
Knock sensor
ECU

first, check to make sure both knock sensors are plugged in, however-
most commonly, your knock sensor wire(s) are brittle, broken, shorting to ground. do the SOGI rewire, and that'll likely cure the problem. here's how: http://www.supras.com/06/techcenter/display.php?QID=69

-shaeff

 

[mkIIIman089]

Anyone else think its funny that the CE light was on for so long it burned out?

 

[shaeff]

^ haha, we think so much alike it's scary! i wasn't going to mention that!

-shaeff

 

[mkIIIman089]

Great minds...

 

[smagnotta]

if the tps is bad will the one off my 87 turbo work?

The TPS is different for pre 89 and post 89 Supras since the throttle bodies are slightly different. The pre 89 ones have a blue tag and the post 89s have a red tag. Since this is a post 89 car you need the red tag. Check out the color of the TPS tag because the previous owner(s) may have slipped a pre89 throttle body in there with a blue tagged TPS...

There are other differences too but the color gives it away and if you order it from Toyota they mention the color because it is a handy way to reference them.

^^ Someone just stated they have both.