'90 Accord EX - Check Engine Light & Very Poor Performance

[BS13]

Ok, this is the latest scoop. The information is from the dealer. I have red flags going up but they could be correct. Any one want to give me your comments?

This what they say:
Oil has gotten in the connectors, in particular, the coolant temperature and O2 sensors. Plus the wires were cut and new connectors installed at both locations and they said the splice was not a good idea in that alone could upset the readings the ECM recieves. The mechanic stated the O2 sensor is very sensitive. We know that.

They are saying because the oil has destroyed the wires AND the connectors that a complete engine wiring harness will be needed. $$$. Plus they rambled on about all the oil leaks that need to be fixed.

I think they only did a cursory inspection and tried to do a good explanation of what could be the problem. But I don't believe they have given it to me truely straight.

The enigine is oily on the back side but not so bad where I have to add oil in between oil changes. Plus the distributor did leak some oil in the vicinity over the coolant temperature sensor. I replaced the O-ring in the distrubutor and believe that is resolved.

So the bottom line questions are this: 1) Will wires that have been spliced into (assuming a good splice) effect the reading to the ECM, 2) Will connectors dampened with oil effect the readings to the ECM, 3) Can't the connectors be cleaned and still operate? - remember that when new connectors were installed they were not oily, but there was no change in the symptons, and 4) why would I not get other engine codes from the problem sensors.

I can disconnect any articular sensor and get that engine code so something is working.

Any one, any thoughts? Am I getting the run around? The dealer says it may be time for a new car.

[jeffcoslacker]

My friend's '89 Accord had a lot of issues relating to bad wiring...the wiring they used in those years seems especially suceptible to insulator cracking and corrosion and shorting between bundled wires...excessive heat and oil contamination makes it worse...his were a mess all along the top of the motor...just bend a wire and it would split in six places or shed insulation

A proper splice shouldn't affect the O2 sensor reading, they operate on small voltages but should work fine...I think there's a service connector on top under the hood you can probe and see if you have a signal stream from the O2 sensor with a voltmeter, you try that yet?

They could be on the right track, but it sounds like they are just guessing...probably hoping you'll go away. Ask them if they are willing to guaruntee the repair will fix it, that's usually the indicator of how sure they are.

You try moving the harness around while it runs, see if it reacts to it? That's where I start when I suspect bad wiring...

[BS13]

Originally Posted by jeffcoslacker

My friend's '89 Accord had a lot of issues relating to bad wiring...the wiring they used in those years seems especially suceptible to insulator cracking and corrosion and shorting between bundled wires...excessive heat and oil contamination makes it worse...his were a mess all along the top of the motor...just bend a wire and it would split in six places or shed insulation

A proper splice shouldn't affect the O2 sensor reading, they operate on small voltages but should work fine...I think there's a service connector on top under the hood you can probe and see if you have a signal stream from the O2 sensor with a voltmeter, you try that yet?

They could be on the right track, but it sounds like they are just guessing...probably hoping you'll go away. Ask them if they are willing to guaruntee the repair will fix it, that's usually the indicator of how sure they are.

You try moving the harness around while it runs, see if it reacts to it? That's where I start when I suspect bad wiring...

My wiring does not seem so bad that it cracks. Just the opposite, but for example the wiring close to the O2 sensor has discolored somewhat. I had a hard time telling what wire was what color when I first started to diagnois the problem(s).

I'm not sure about the service connector. Is there one?

I might be tempted to ask if they guarantee this work, in writing.

Thx

[jeffcoslacker]

Originally Posted by BS13

I'm not sure about the service connector. Is there one?


Thx

Not sure...but most Jap cars before OBD-II had a six or eight point test connector under the hood that you could put a DVOM on the individual terminals and get readings from the o2, TPS, MAP, etc while it ran.

The cap should number each terminal, the manual will tell what voltages should be present in what conditions...