groznyiv

iTrader: (1)

I have a 1989 convertible with a USDM S5 TII swap. The ecu is for the USDM TII but the wiring harness is the stock NA with the proper changes to make it work correctly with the TII motor. Everything has worked great for the first 2000 miles. I did the proper 1000 mile break in procedure etc.

Last night I replaced the speakers under the dash and in the door. The installation was easy and the stereo sounds great.

Today I started the car and drove it for the first time since replacing the speakers.

The car has no emissions or aws. It still has the BAC.

The car now will idle a little rough. Before it was smooth as silk once warm.

Under load past 6500 rpm is stumbles badly.

I ran an error code check and it gave me the following codes.

13 ==pressure sensor
25 ==solenoid valve pressure regulator control
30 ==split air solenoid
31 ==solenoid valve relief one
32 ==solenoid switching
33 ==solenoid valve port air bypass
38 ==solenoid valve AWS
42 ==solenoid valve turbo boost pressure pre control

Most of these are because I do not have emissions control which are removed and blocking plates installed.

I checked for vacuum leaks and found none.

The only thing I found was a bolt loose on the LIM and I tightened it with a few turns.

Any help would be appreciated and yes I did search first.

Thank you,

David

RotaryRocket88

iTrader: (7)

There's your potential problem. Test the pressure/boost sensor. It's throwing a code for some reason, and you need it to supply the ECU with proper pressure data. If it's not working, you could be running rich or lean all over the map. If it's a lean stumble you're feeling up top, engine damage is on the way.

groznyiv

iTrader: (1)

I have a 1989 FSM for the car.

I tested for continuity of the pressure sensor and got a 1.3 ohms reading off the brown wire with the black stripe. The other two wires when checked for continuity both read 136 ohms for the brown with white stripe and 1000 kohms for the green with yellow stripe. I then tested the voltage with the key on and the D terminal(brown with white stripe) reads 4.96 volts. The other two wires read in the low milli-volt range.

Do you know of a way to test the pressure sensor under the 3.9 in Hg required for the voltage test? Other than getting a vacuum pressure gauge and pump?

Could the pressure sensor cause the idle problem as well as the high rpm stumble?

Also, my temp gauge started acting strange after I replaced the speakers. It will not read anything above a 1/4 of the way up the gauge. Before it read when warmed almost halfway. It also goes back down to below cold when you rev the motor. It is an almost instant move back down to the bottom.

Thanks again for the help,
David

satch

iTrader: (1)

EDIT:

W/key to on and plug connected to the sensor the Br/W wire reads close to 5 volts. The Br/L wire is the ground wire so it should read 0 volts and the G/Y wire should read 3.4 to 3.6 volts and the hose does not need to be disconnected and plugged if you don't want to go through those extra steps. Since this last wire,G/Y, does not match up with your reading you might want to check one more time and see if you have a sufficient reading.

groznyiv

iTrader: (1)

Thanks Satch,

I checked again with the key on.
Br/W 4.97 volts
Br/B 8.2 milli volts
G/Y 19.6 milli volts

Is there a problem with my ECU?



David

satch

iTrader: (1)

The ECU outputs a signal (Vref) to the Br/W wire but the Green/Yellow wire is an "input" signal "to" the ECU. Appears your sensor is in need of replacement, and I guess you read the voltage w/the plug connected to the sensor.

groznyiv

iTrader: (1)

Yes I was checking with the sensor plugged in. I tried regrounding the sensor and testing again with the sensor plugged in and my readings were

Br/W 4.98 volts
Br/B 0.03 volts
G/Y 2.2 volts

It is still below the range of 2.8-3.2.

Thanks again for the help,

David

satch

iTrader: (1)

I believe the S5 Boost sensor should read 3.4 to 3.6 volts.

groznyiv

iTrader: (1)

Then I guess I am in need of a sensor. New ones are about 400.00. Do you know of anyone with a used one for sale?

satch

iTrader: (1)

https://www.rx7club.com/search.php?searchid=9125801