MSefi.com read only forum (Jan.15,2018)

I've been going through trying to get things setup with my MS unit so that I can start the engine for the first time with it.

For now I've just been checking all the sensors to make sure they are functioning and I came up with a problem with the TPS.

In Megatune it was registering 30% with it fully closed. If I jiggled the wire leads it started moving erratically all over the place but when I moved the throttle, I would get nothing.

So far what I've tested:

MS ECU with the stimulator: TPS functions fine
Multimeter connected to TPS sensor: Get a reading of 1.7 at fully closed that goes to 6.2 at WOT
Multimeter connected to wiring only: All wires show they have continuity through them
Multimeter connected to wiring, wiring connected to TPS: I get no readings at all.

I've checked the plug and it looks correct. Could it not be seating properly in the TPS? Is there any kind of remedy for this?

Oh, the throttle body is an Edelbrock universal 4-bbl, 1600cfm Dominator flange with a GM style TPS and GM/Delphi IAC.

Thanks for the help,

Did another test and was able to get a reading through the end of the TPS wires when they were connected to the TPS sensor. The problem though is that its not consistent. If I hook the meter up, I might get nothing. But if I jiggle the wires at the connector, then I'll get the readings. But if something gets bumped, it will go dead again.

So how do I know if its the connector on the wiring harness or a bad TPS since both test fine independently of each other?

Hi

Is this really correct Q Multimeter connected to TPS sensor: Get a reading of 1.7 at fully closed that goes to 6.2 at WOT UQ

The TPS is fed by a + 5 V supply so to get 6,2 at WOT indicates that there is either a fault in the wiring or that the +5 V from the MS
is damaged ( less likely)

Best regards

Heribert

Heribert wrote:Hi

Is this really correct Q Multimeter connected to TPS sensor: Get a reading of 1.7 at fully closed that goes to 6.2 at WOT UQ

Best regards

Heribert

Heribert, that was tested with the throttle body off the car and nothing hooked up but my multimeter to the TPS sensor. If I have the multimeter set to the 20K Ohm scale, I get anywhere from 1.70 at close to 6.24 at WOT with the multimeter connected to just the ground wire and signal wire.

Am I testing this wrong? I'm still thinking there is something wrong inside the plug because if I connect the multimeter, I initially just get a '1' reading on the ohm scale. But as I move the wires around near the plug, that's when it starts to give me a reading. However, if I don't leave them in a certain position, then the reading goes dead again.

Thanks,

Well, I think I figured it out. I appears the pre-made plug/pigtail I had bought didn't have the connectors fully inserted so they weren't making good contact. I pushed them into the connector further and then connected everything back up and now it seems to be functioning properly.

Thanks,