TPS Voltage Drop when Accessories are on.

[supraguy31]

Power Drop:
What's the condition of your alternator?

Grounding:
Was the bolt you used in the trunk painted? If so, remove the bolt and use a wire brush (or similar) to remove any and all paint from the entire bolt. Also, make sure that the threads and/or hole are paint free as well. Basically, you want metal on metal... Additionally, some di-electric grease is a good thing to use to help with conductivity and to reduce rust/corrosion.

Running a second ground up to the engine bay will not create a ground loop. It will provide additional grounding. Attempt mimic the stock setup.

Alternator is in good condition, Doesnt seem to have any problem keeping things charged but I dont have anything that you really pull a huge amount of current other than the stock things.

The Bolt that Im currently grounded too is right by the passenger tail light in the bottom of trunk area right by the Fuel Sending unit cover. I think it would be of best interest to pull that cable out and run a long cable from the batteries negative terminal up to the engine motor mount. Run a Smaller guage from the batteries negative post to the fender as this is the way the Stock Setup is. Once this is done, do another test to see what it does.

Any more recommendations would be great.

 

[3p141592654]

Consider that your alternator ground reference is the engine block. Also consider that the factory battery ground goes to the block, and the chassis near the under hood fuse box. You want to replicate that setup regardless of where the battery is located. The factory did not ground only to the chassis and call it a day, and you shouldn't either. Your test data illustrates the issue perfectly.

 

[whitemike]

:cry:

 

[Nick M]

A couple of things. Voltage drop on the ground isn't good. 13.5 volts when the lights are on is normal. Voltage went down because current is flowing. That is normal. Just an FYI.

 

[supraguy31]

Ok All.

So I went ahead and reconfigured the ground wires. Bought new wire and went from the Battery up to the engine block and also put a short grounding wire the the frame.

There is no change when I did this. The TPS voltage when lights are off are still around .4v and when I turn them on the voltage drops to .15 to .20 as before. Going to see if there is still current being pushed through the Negative terminal and will reply Shortly.

 

[supraguy31]

I want to thank you all for all the Help with this Issue. Even though the Issue is still there Im finding more and more Issues. As of right now, It looks like the TPS is Dead. Start the car up and the Voltage is 0.00 at Idle. Give it gas and the Voltage moves but car AFR are all over the place. Now I see how a Throttle Position Sensor actually works and what it does to an engine if its partically going bad or just bad all together.

So time for a Beech TPS adapter or another Q45 TPS......