wiring help needed... What all is connected to your ground at dipstick

[RWKHausSupply]

1990 renix.. Need to know how many terminals on a stock renix engine are at the dipstick ground location? I replaceced the motor and only connected the one main battery cable and after reading about how there seems to be 2 or more there as well as only seeing 3.46 volts at the TPS harness but yet with a direct ground that goes up to around 4.6.. I am thinking I missed a ground wire for the ecu or somemthing?

It runs ok but has always had a lope as well as odd power band I thought and maybe its due to the voltage / gound that the ECU has to deal with?

Help with pictures also would be great! And anyone have a stock grounding diagram that shows the ecu grounds also?

Thanks in advance.

[langer1]

ECU TCU and heater motor. Do you have the ground strap from the back of the head to firewall connected?

[RWKHausSupply]

yeah I think so,.. But I also have I think 7 various 4ga ground wires added. From like the side post - to liek the firewall, engine, alt bracket, and then cross connections from the firewall to the opposite side of the firewall, ect..

I am just worried that the ECU or sensors have a ground wire someplace I didnt connect back up..

[XJING]

I used to have that "lope" too, try these enhancements to your electrical system. When I used the bigger cables from the alt and to the battery from the starter relay and put in new grounds the "lope went away. Anyways heres the link
http://www.olypen.com/craigh/electrical.htm

[langer1]

yeah I think so,.. But I also have I think 7 various 4ga ground wires added. From like the side post - to liek the firewall, engine, alt bracket, and then cross connections from the firewall to the opposite side of the firewall, ect..

I am just worried that the ECU or sensors have a ground wire someplace I didnt connect back up..

I have two wires at the dipstick running into the firewall, engins never been out. One is the TCU out- and the other is ECU out-

[8Mud]

The ECU has some resistance built into it, like one third, half a volt or something.
Something to try, find all the connectors the TPS wire goes through ( I have an earlier model so I can't help you much with this) and measure the standing voltage in various ground wires (from the TPS or other sensor ground, to chassis ground), after each connector. You can also do it at the ground wire, before the bolt on the dipstick holder. The current that doesn't make it to ground, stays in the wire as standing voltage. Every connector that adds resistance, ups the standing voltage.
The ECU (and TCU) has some resistance built into the ground circuit, so you will never get a perfect ground ( with no standing voltage or resistance).
4.61 volts is what I have for my tranny side TPS in. I have 4.8 for the ECU side TPS in.
I wouldn't hook up a chassis ground to the ground wire at the TPS, I get a feeling the gound from the TPS through the ECU to the dipstick holder has little resistance built into the ECU (or TCU) on purpose (by design). It's likely a capacitor to protect from surges or something, just guessing.