Sometimes PowerFC throws a CEL because of the throttle position sensor. I didn't changed it yet and I belive it makes the idle problems as well.(rev drops to 300 rpm)

TPS voltage sits 0.37 at idle 3.85 at WOT(no mat) The subaru manual talking about the adjustment of the tps sensor. Has anyone tried it yet?

1.Connect all connectors.
2. Loosen throttle connector screws
3. Adjust throttle sensor while throttle valve is fully opened

- Turn the ignition ON
- Adjust it to specified voltage between ECM connector terminals
- Tighten the TPS installing screws


I actually couldnt understand this =) How do you make the adjustment? While the pressing the pedal tighthening the screws?

 

Just do it with the engine running at idle speed with the throttle closed. Adjust the TPS until its reading on the commander/laptop between 0.5 and 0.6v closed. The closed value is more important (to the ECU) than the WOT value.

Andy

 

Thank you Andy I'll try it tomorrow.

 

i've posted on another thread but this one seems more relevant. I've been trying to work out the cause of a hesitation on sudden throttle openings. As it only seems to do it from a very light throttle cruise, I looked at the TPS and it was reading around 0.3 v at idle. So I adjusted it up to 0.53v and the throttle response does seem a little better although still not perfect. Cruising at a throttle position of 1v or above completely solves the problem - it's only when holding throttle at below 1v that it hesitates when flooring it.

A few solutions spring to mind:
1. Fit a new TPS (the old one went dodgy and had 105k on it, and was replaced with another second hand because of the cost of buying new from Subaru!)
2. Take the TPS off and see if anything needs cleaning out
3. Adjust the idle position higher up to see what happens, maybe 0.7v. I'm reluctant to go too far, say to 1v, because it might throw out all the mapping?

Any opinions?