Sensors Required for SR to run

SON240sx Automotive
1

Can anyone tell me if this is a complete list of what needs to be hooked up in order for an SR to have a nice stable idle.

MAF (if you want to rev over 2400rpm)
CAS
Injectors
Coils
IACV? I would assume yes
Ignitor
ECT
FPR Vaccum

So things that do NOT need be hooked up for a stable idle

O2
Knock Sensor
Wastegate vaccum
BOV vaccum
TPS

Correct? Responses with reasoning is helpful

Part 2

If the MAF is hooked to the throttle body via an intake pipe and filter but the turbo is not piped in at all will the engine run okay? How much are the fuel maps setup for the turbo? Or does the turbo suck more air past the MAF and thats how the ecu knows to richen the fuel?

Incase you haven’t figured it out I am tring to eliminate all but the essentials trying to find out what is causing a rough/unstable idle. I have done all the basics so now I am tring another approch. Thanks for any insight or info you guys can provide.

2

grounds, a bunk o2 sensor can also cause un stable idle

3

I know all sorts of sensors can cause bad idles… which is why I want to unplug everything not needed and just let the ECU correct for them. And the grounds are all very solid… I have done all the obvious stuff for bad idle.

4

ECT? Engine Coolant Temperature?

If not, then CTS (Coolant Temp. Sensor) as well perhaps?

5

yea ETC is Engine coolant Temp.

CTS is for the gauge and doesn’t mean shit. :slight_smile:

6

Well, the fuel maps aren’t really setup for a turbo… they are setup for variances of engine load (as a function of a few things like MAF voltage and TPS). A turbo just affects the amount of air coming through the MAF and as a result the MAF voltage goes up and so does Load.

This relationship should not change in the example you described. In fact, what you described is really just a blow-through setup with no turbo.

7

Dan,

Okay so the motor should run fine like that then. That will help in the diag. process. Although to be a blow through setup it would require the MAF to be behind the turbo. If the MAF is just hooked up to the throttle body with no turbo it would just be a normal NA setup I think.

Hopefully I can find the answers I’m looking for this weekend because I intend to crank up the boost with the new exhaust before I put the car to bed for the winter. :slight_smile:

8

Yeah - that’s what I was trying to say. Essentially you are creating a blowthough system with no turbo.

The MAF doesn’t know there is no turbo there…it can be our little secret.

9

haha… k

10

you should run vaccum to your bov it might leak

however with no turbo i doubt it would leak.

if the turbo is bolted up make sure its not just spinning with no resistence. with no resistence it may damage it if it overspins for too long of a period

11

Yea I have vaccum running to my bov from the tb. I can’t find any leaks anywhere around the bov. Any suggestions on other ways to check I might not have thought of?

12

THE SENSORS you need to run a car are few.

coolant temp
air intake temp
Crank angle sensor
Throttle position sensor
Fuel press sensor
MAF ( or MAP )
NB 02

EVERYTHING else you’ve mentioned is part of a mechanical or elelctonic subsystem that gets it’s input fully or partially from the above sensors

13

I know you don’t NEED

O2
or
TPS

does the SR even have IATS or Fuel Pressure sensors?