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Followup To
Question -
--Dear Sirs:
I have a 1986 laser 2.5 that I am having problems getting through emissions. I have replaced the catalytic converter, EGR valve and oxygen sensor. I am way high on CO and I also get a fault code of 52 (Oxygen sensor output indicates rich too long) I have read that should replace it with a 3or 4 wire sensor and ground it to the battery to help with the problem but I'm not sure what to do with the other wires or if I should just ground the one I have differently. The car seems to run great and the fault codes don't always show up witch leads me to believe it is a ground problem. I already replaced the sensor with a new one but still failing emission tests. Any advice will be greatly appreciated.
Sincerely,
Joe Kampa
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Followup To
Question -
Dear Sir:
I have a 1986 Laser XE 2.5 and I am getting a fault code 33. My problem is I do not know where the relay is located any advice would be greatly appreciated.
Thanks
JPK
Answer -
Hi Joe,
I have to admit ignorance on the Laser model which I believe is an imported model, correct? On the domestic Chrysler line thare is typically three relays mounted on the driver side inner fender and the middle one in the A.C. relay. Another way to find it would be to determine the color code on the compressor clutch wire, then look at the plugs for all the relays until you find one with that same wire scheme on one of its wires and that would have to be the relay in question.
Roland
Answer -
Hi Joe,
I am still in the dark about the Laser model. Did you find the AC relay? I have the '85 and the '87 FWD shop manuals for the domestic line of cars and no 'Laser' is mentioned. Is that perhaps a Canadian version of a US model, and if so do you know which? When you say it is 2.5, is that the standard throttle body injected Chrysler-built 2.5L 4 cyl. engine? If yes to both the above, then we may not be so confused.
Let me assume that is the case until I hear otherwise from you. As to the hi CO and the code 52, I would not assume that the oxygen sensor is bad. First I would suggest that you take a look at the spray pattern from the injector while the engine is idling to make sure that it is a fine ever spray on the throttle plate. Any sign of large droplets would make me believe that you have a defective injector that is not controlling the fuel flow properly.
The other things that can make for a faulty mixture (too rich) are a coolant temp sensor that is not measuring the temp of the coolant accurately. So check to make sure that the resistance across the sensor is in the range of 700 to 1,000 ohms when the coolant has reached normal operating temperature (200F). Also the MAP sensor may not be reading accurately, but without a diagnostic readout box there is no way to evaluate, except to take a reading of the voltage on the dark green/red wire of the MAP while at idle and see if it is in the range of 1.5 to 1.7V. Ideally one of the sensors that controls mixture will malfunction sufficiently to set a code. But they can be off-value, and yet not so much as to set a code.
So try checking: injector spray pattern, coolant temp sensor, MAP sensor. Also check the throttle body temp sensor which should read 400 to 1,500 ohms when the throttle body is warmed up to 200F. Maybe one of those will be found wanting and solve the CO issue after it is replaced. The original oxygen sensor is a 3 wire unit. I wouldn't try substituting something else until I was satisfied with the other tests and the other reasons for a too rich mixture.
Roland
Hi Roland:
Thanks again for your help,the injector and throttle body coolant temp sensor are new aand working and if I unplug the map sensor vacum line I get an immediate fault code and the car will hardly run witch leads me to beleive the map sensor is fine.The original 02 sensor is a one wire non heated version and I'm sure it's the problem I just need to get a good ground, the car runs great but the fault code pops up from time to time here is a web address for a web site tyhat addresses the fault code #52
minimopar.knizefamily.net the car was purchased new by my father in 86.
Thanks again
Joe
AnswerHi Joe,
I don't have the '86 diagrams, so maybe you do have a non-heated sensor? The '87 is heated, but I now see that the 85 is indeed a single wire. I wonder though if you changed to a 3 or 4 wire heated sensor would the calibration of the signal not be incorrect?
One other suggestion: do take a look at how the injector is functioning. Watch the spray pattern at idle for a nice fine even spray, and then have a helper turn off the engine and watch for an after-drip. If you see that drip it could very well be the cause of your rich running, instead of the oxygen sensor. That is how my injector behaved when it went bad.
Roland
Hi Joe,
The oxygen sensor, even a 3-wire, is heated. There just is not a separate signal ground wire, one ground serves both the heater and the signal ground. If you wanted to get a separate signal ground, you might find that the black/light blue wire that serves as the signal ground for the TPS and the distributor would work (at least that is what my '87 manual shows as a signal ground point). You could splice-in the fourth wire of a 4-wire sensor for the same engine (as used in my '89 2.5L) at either of the other sensors, or at pin 25 of the red connector at the logic module. I don't know whether this will work or not, but it might be worth a try if you believe a new 3-wire sensor won't solve the too rich problem.
By the way, our '89 LeBaron Coupe was also formely my Dad's car which he bought at age 86, and then we inherited at his death in '92. So it has sentimental value too.
Roland
