Hello everyone

Just a few questions about the idle issues with manual conversions. Ever since my conversion many moons ago I have had the dreaded hanging idle issue which was then rectified with a J3 chip, however I started to have issues with the J3 chip so I started running without it for a while. Long story short, car was unregistered and kept off road for a few years with the occasional start up and drive around the block.

As I am putting it back on the road, I want it to run good again and started to tinker again. The battery has always been disconnected after every start up/drive to make sure the battery doesn't drain so the ECU has always pretty much been reset. After start up and getting it up to temp, I noticed that when I unplug the TPS the engine idles just fine with no rev hang. I admit I haven't taken it for a drive with the TPS unplugged but this has never happened before. Pre J3, with J3 and post J3 chip usage, the engine always "choked" and stopped running as soon as I unplugged the TPS.

So my questions:

What does the TPS actually do in this situation? Is it meant to control the idle during changes in engine strain? Such as when AC is turned on, or when full lock power steering pump? Can I run the car without the TPS and how will that effect daily driving?

Thanks in advance!

phongus

Standard throttle body?

TPS lets the ECU know when the throttle is closed, open, or at WOT.

There are a couple of voltage trigger points that the ECU looks for.
All are "Voltage at key-on + xxx Volts"

Can't remember the values now.

0.4 - 0.8v for closed throttle, 4.0v Wide Open Throttle.

Yes, standard throttle body.




Thanks for the information.

So I assume the information that is sent to the ECU will let the ECU adjust fuel to air ratio? Would that mean, if the TPS is driven disconnected, the fuel to air ratio could be way off causing poor fuel economy or poor performance over all?

I am currently running the auto ECU with a manual conversion. Did the ECU trick with resistors and it hasn't been an issue running. Just have had the idle hang issue that's all. I remember reading somewhere that someone has blocked off the TPS...but not sure if that would be detrimental to the over all performance.

I have a J3 chip, but it plays up every so often and leaves me stranded until I disconnect the J3 from the ECU. Has happened 3 times now so I don't drive with the J3 chip. In saying that, I get the occasional idle drop and engine stop when pushing the clutch in and preparing for a stop without the J3 chip.

TPS works, as the engine changes revs when I disconnect and reconnect.

Thanks for the help