DFlintstone

Hey cruiser. I found in a pinch you can actually photo the screen. This here is a starting circuit.

Poster, I think he will say the ground to the ECU just doesn't go through the C101 if you don't have one, but I don't know!

cruiser54

Yes. Yes. LOL. Basically it's the CTS,TPS and IAT grounds grouped together going to a single wire with a crappy crimp that ends up going to another crappy 3 wire crimp for the MAP, ECU, and diagnostic connector. If you have a C101, it runs through that but you don't need to do anything special. If you don't have a C101 it's still just the same....It's really quite simple once you peel off the split-loom protective covering on the harness. You're just taking the two 3-wire splices and soldering both sets together .

DFlintstone

HEY! I got that /\ lol....I was going to suggest he service it but on second thought I guess it might make sense to see it it needs any solenoids before pulling the pan? (and thanks for the ground info).

sansocal

So I got the wiring harness apart and found a crimp that didn't look factory, it had 4 wires on one end and 2 out the other. All three tps, map, and mat sensor grounds go to it.

I also noticed the resistance is about 3 ohms with the key off, and 80 with the key on. Should I just take the 6 wire crimp apart and solder all 6 together??

cruiser54

That's how they did it in those harnesses. The crimp looks like the band you'd put on your parakeet's leg!! Cut the crimps out and solder teh whole bunch together. More than 1 ohm will give problems. Nevermind with the key on.

sansocal

So heres the deal: With the key off i got the resistance down to .9 when cold and 1.9 hot.

Key on its like 15 cold, 55 hot.

I replaced the negative battery cable, put a battery cable from intake to firewall (i'm desperate) and cleaned all the ground connections to the passenger side block/ oil dipstick tube.

Now when I drive it will do the same symptoms but will down shift when coasting down a hill. Or at least that's what it feels like, but the engine is braking for me when I don't want it to. That down shift engine braking thing is quite noticeable and definitely not normal.

Any thoughts?

cruiser54

While probing the ground circuit, wiggle the harness that runs along the valve cover and the harness over by the MAP sensor. Any fluctuation in your reading?

Over by the trans dipstick tube are two large connectors, one black and one gray. All the signals between TPS, TCU, NSS, and trans solenoids travel through these connectors. Unplug them, clean 'em out with contact cleaner, make sure no pins are bent over and then plug them back in.

sansocal

heres a video of it: http://youtu.be/MtUUzvwH2UA

sansocal

No fluctuations when wiggling, going to ace right now for the cleaner.

cruiser54

At 1.9 ohms, wouldn't be a bad idea to repair the sensor ground circuit.

sansocal

Out of the 6 wires that are solder together, one, a purple or violet/white wire reads 1.6 ohms to the negative battery post. I can't find it in my chiltons manual diagram. Do you happen to know where this wire goes?

cruiser54

Only ever seen six, all brown with white in there. I'll go look in my manual.

cruiser54

Only things with any violet/trace are knock sensor input and CPS.

Did I ever send you or post for you the repair procedure for the sensor ground circuit?

sansocal

The solder together of the 6 wires? Yes, I did that.

Sorry, it is brown white, and it goes to the drivers side firewall. So I guess the next thing is to check the ECU ground..

cruiser54

That's probably the sensor ground circuit to ECU wire. The ECU grounds at the dipstick tube stud along with the oxygen sensor, injectors and knock sensor..