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The Mighty Pieholio
 
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Quote:
Originally Posted by flat6_911 View Post
Steely I have my new o2 sensor disconnected. when I installed the new o2, the connector in the rear crumbled in pieces. I think PO set the mixture with no o2 sensor (or he thought it was connected but the connector was in pieces) I drove it for the past 3 years with no issues and o2 disconnected.
The steel female receptacle is still ok. Crumbling aside.
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Old 10-03-2017, 01:52 PM
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Originally Posted by Bob Kontak View Post
That said, get the O2 sensor in the loop once you figure this problem out.
I have an extremely limited level of experience with CIS, but I'm with Bob on this - I just think/suggest if you had everything together it would help in the troubleshooting dept (one less variable). What you think it running rough (during relay trials) may be the lambda ECU normal response trying to compensate for no O2 input. No disrespect intended.

My PO told me I didn't need the O2 sensor, but it turned out I had a completely different problem that made him think the O2/lambda was bad.
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Old 10-03-2017, 03:38 PM
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If you search you'll find the guy that sells a fix for the o2 connector. I think the lack of on o2 sensor signal just tells the jetronic brains to run in open loop mode the whole time. The other guys would know what happens if you run without the o2 sensor AND the relay.

This feels like an electrical issue. Maybe run some continuity tests between the relay wiring under the front seat pass and the connectors in the engine compartment? So tough when it's intermittent like that. It could be an electrical issue with the jetronic control box itself. Maybe someone could lend you a known good one and you could switch it out and see.
Old 10-03-2017, 03:50 PM
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The OXS relay gets power from the Fuel Pump relay (confirm me), so make sure the FP relay is sending power consistently by sticking a meter in the OXS relay socket (w/o harming pins) (86 hot to 85 rtn), and monitor, or try another relay.

If the power there is good, it's the relay. If not, and the FP is ok, it's the wiring or contacts.
Once that's working, is the FV working,whining? I think that is the only thing left to operate, even if you are ignoring the O2.

The oxs relay provides power to the FV and the ECU (buffers and handles the O2 sensor output, which might be being ignored).

Aside from some relay cartoon engravings, the relays you and others showed are essentially all good/the same. 85 and 86 may be flipped on the dwgs, but it is ok as long the relay itself is terminated to the correct pins. Pins 87, 87a, 87 b, should all be common to ea other (hence the measurement I asked you to do).

If the relay is bad, the FV will never get power (and either will the ECU).

Consider too if the OP tuned it w/o the O2 3+ years ago, maybe you're due for a check.

How quickly is the bad relay switching off/on? Not that it matters.
Getting colder up where your are? Let us know and good luck.
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Last edited by steely; 10-03-2017 at 06:38 PM..
Old 10-03-2017, 06:35 PM
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^^^^ this.
Old 10-04-2017, 06:28 AM
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Quote:
Originally Posted by steely View Post
The OXS relay gets power from the Fuel Pump relay (confirm me),
Yep. The lambda relay electromagnet gets it power from pin 30 on the FP relay. That's what I was rambling about in post #10 when we overlapped.

I think there may be a connection problem on the 86 or 85 side of the Lambda relay, primarily because OP can press the electromagnet together and all is well.
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Old 10-04-2017, 11:20 AM
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okay, I might of found the solution.

I work in isolated construction sites for long periods of time. I only get to drive and work on my car 1 weekend a month. I'm currently away but I've been reading old posts on the forums all week in preparation for when I get back.

I stumbled upon a old thread about a fellow pelican that was getting out-of-wack readings from the o2 sensor because the shielded wire was grounding with the middle wire of the harness. Not long after, I spot a more recent thread with someone that had the same issue.

I did mess with my o2 wire prior to this issue. I twisted the wires from the shielded green wire together and put a heat shrink to protect it incase I ever decide to run a o2 sensor again.

Could this be it? could the "shield wire" be giving the ECU some sort of reading from the "center wire" of the o2 harness? could I remove the wires at the ECU ? (pin 2 and 4?). I'm assuming it was giving the ECU a lean reading and the car was compensating with A LOT of fuel.

Cant wait to get back home and figure this out, its killing me
Old 10-09-2017, 03:33 PM
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Quote:
Originally Posted by Bob Kontak View Post
Yep. The lambda relay electromagnet gets it power from pin 30 on the FP relay. That's what I was rambling about in post #10 when we overlapped.
Thanks Bob
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Old 10-10-2017, 09:22 PM
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Quote:
Originally Posted by flat6_911 View Post
okay, I might of found the solution.
...
I stumbled upon a old thread about a fellow pelican that was getting out-of-wack readings from the o2 sensor because the shielded wire was grounding with the middle wire of the harness. Not long after, I spot a more recent thread with someone that had the same issue.
...
Could this be it? ...
I think you could be on to something here.
Man I wish I had a schematic of that ECU.

guessing, I think the O2 sensor only ever sends (or its receiver only ever sees) a small voltage or nothing at all (floating input). Some ckts however are designed to withstand a shorted input, but some aren't. either way, you may have found the cause - please let us know when you get back and get a chance.

I don't know if you can disconnect at the ECU - probably yes - but I don't know if it is a simple connector or a solder termination. I would be inclined to save the original harness and just try dressing the unused O2 sensor end by making sure no wire strands were exposed. Your call of course.
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Old 10-10-2017, 09:32 PM
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SOLVED!

That's exactly what it was. The ground wire that's wrapped around the o2 signal wire were in contact with each other. I trimmed back the ground wire and heat shrinked it. All good now, runs even smoother with the new relay
Old 10-13-2017, 03:31 AM
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Nice work!
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Old 10-13-2017, 05:09 AM
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+1
cool
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Old 10-13-2017, 09:34 AM
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Awesome .
Old 10-14-2017, 04:26 PM
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Thanks for all the help



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Old 10-14-2017, 05:34 PM
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