CBJeeper

I have been experiencing no-start cranking and high idle. TPS is brand new Standard Motor Products. I am thinking grounding issues. I followed Cruizer54's Tip #6 but find my brown with white bundle to be nicely crimped per the factory. When I measure from ground on the TPS connector to battery terminal ground, I am getting 5.4 Ohms. When I measure to the crimp I get 1.2 Ohms. This seems high. I just finished adding a #4 cable from the body to an intake manifold bolt. I am going to add another from the NEG terminal to the body at a the radiator shroud. Lastly, I am going to redo the battery ground cable and freshen all the wire connectors (again). Any other Renix owners with experience to share on this?

bad_idea

The idle air control valve may be gummed up. Pull it out and inspect. If it is covered in black soot, clean it off. Also clean out the passages in the throttle body. My IAC acts up every now and then, causing the idle to run up to 3k. Sometimes I shut it down and start it back up, it will act right. Other times I revved it a few times and the idle settles out. Really is a finicky old *****, but I love her.

djgrayxj

If you pull it out and inspect the idle air control valve don’t turn it, just clean it with an old toothbrush.

CBJeeper

That is a component that I have not yet checked or cleaned. Thank you for the tip.
Funny story... I pulled in to a FedEx terminal this afternoon and when I got out, a young guy walked over and said, " I just had to come over and tell you that your car is awesome, it is just so awesome". Makes a proud owner beam with pride. I too, just cannot get enough of my XJ and I have owned more cars than I could count.

bad_idea

It makes me sad that my XJ has reached the point the younger generation thinks they are a cool old car. I grew up in the 2000s when these jeeps were **** boxes. It pains me my 90 is now 35 years old.

CBJeeper

At the same time, it is awesome that many have held up as they have and are still reliable drivers. It is a point of pride for me.

lawsoncl

You removed and cleaned up the ground connections on the stud by the oil dipstick? That's where the TPS ground lands after that wierd crimp in the wiring harness. As a last resort you can add a ground from the TPS to the intake manifold.

CBJeeper

Thank you lawsoncl. I have since carried out the following and, so far, all seems good:

• Replaced my 34 year old battery ground cable with a new 2 AWG and again wire brushed/cleaned and applied OxGard to all surfaces.
• Added a negative battery terminal post with wing nut for the new ground cable.
• Added a 4 AWG cable from the chassis ground strap bolt over to one of the intake manifold bolts.
• Added a 4 AWG cable from the negative battery post to one of the 10mm bolts on the radiator shroud.

Intersting enough, my resistance from B terminal on the TPS to battery ground only dropped from 5.4 Ohms to about 3.5 Ohms. I would have thought all my grounding would get me closer to 1 Ohm.

dmoe69

Not wanting to be contentious, but do not add a ground to the TPS. The sensor circuit receives it's ground through the D3 pin from the ECU (yellow highlighted on the diagram). You can also see that there is another splice to check between the ECU and the dipstick (in purple, dipstick ground is at upper right)

CBJeeper

Thank you for the diagram. This is interesting. One of the three wire loop connectors that join the battery ground at the dipstick is brown wire w/ white stripe, same as all the sensor grounds.

lawsoncl

There is a crimped connection in the wiring harness along the upper firewall on the passenger side, where a bunch of brown/white sensor grounds and the ground from the TCM all come together. One of the wires in that splice runs down to the bolt on the engine block. That crimp is literally just the bare wires squeezed together and taped up without any sort of sleeve at all.