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Hi Roland:
I am continuing to try to figure out my 86 laser high CO problems. Yesterday checked everything you said to check and things look Ok but when I checked the voltage from the 02 sensor it was over .900 milly volts and did not jump below .900 I was told it should be vary between .150 and .450 milly volts . The sensor has been replaced less then 2000 miles ago and it is the correct one a OE Bosch unit. Could something else be causing the sensor to not work correctly like the computer it self ? I traced the wires and made sure the thing is not grounded out some where and checked connectors and such.
Thanks again,
Joe
Answer -
Hi Joe,
The fact that you have high CO in the smog test result corroborates the 900 mV output of the O2 sensor. The two are telling you the same thing, that the mixture is too rich. Once again did you look at the spray pattern of the fuel in the throttle body throat where it impinges on the butterfly valve, and did it appear to be a fine/almost invisible spray and when a helper turned off the engine did the spray stop immediately without dripping? If the answer to all those questions is yes, then the fuel injector would appear to not be leaking out extra fuel which would cause a too rich condition.
Another possibility for a too rich condition is that the engine operating temp is not reaching near the 200F level because of a stuck open thermostat for example. The feedback loop from the O2 sensor to the engine controller will not go into effect until the engine senses that it has reached operating temperature. Does the radiator and the thermostat housing get hot after some minutes of operation and does the gauge read about 1/2 scale. Does it get warm enough for the fan to come on when the temperature is hot that day. Does the resistance of the coolant temp sensor (on the side of the thermostat housing) read in the range of 700 to 1,000 ohms when the dash gauge reads 1/2 scale?
If yes to all those then presumably your feedback loop is closed and the controller should be leaning out the fuel mixture because of the 900 mV signal from the O2 sensor.
The other factors that control mixture are the rpm (is there a tach signal, if the car has a tach), the throttle position sensor (if not working should set a code), and the MAP sensor (try to measure the voltage on the dark green/red wire of the MAP while the engine is idling, use a fine straight pin to touch the wire inside the insulation. It should read 1.3 -1.5 volts)
If all those things check out, then I can only suggest that you take the car to a Chrysler dealer and have the tune-up mechanic put the diagnostic readout box on the engine and look at all the operating parameters to see if he can see one that is off-value and thus identify the source of the too rich mixture. I don't think there is anything wrong with the O2 sensor, rather the control of the fuel/air ratio is not taking that reading from the sensor into account or some actuator is not responding properly to what the engine controller is telling it to do.
It may be that the wiring to the controller is not what it should be. Unfortunately I have the '85 and '87 wiring diagrams only, but one or the other is probably relevant. But I am still a bit in the dark about what a "Laser" model is because it is not listed in manuals as a model for 85 or 87. You have the 2.5L engine correct, and not the 2.6L mitsubishi engine, correct?
I remain interested in knowing how this one gets resolved.
Roland
Hi Roland:
Thanks again for the information and the interest in my problem. You are right about the spray it looks like it's coming out of my sink instead of a injector no atomization at all. I found another fault code and I think it's the culprit #26
Fault Code 26-TBI
Synopsis
Notes: For single-point injection engines only
Description: Peak injector current has not been reached
Power loss light: Off
Limp-in mode: None
Possible Causes
Bad connection or wiring - Check the wiring and connections to the fuel injector and the power module (or SMEC) and the injector control lines between the logic module and power module. Clean and regrease any corroded connectors with dielectric grease and repair any shorts.
Fuel injector failure - Check the resistance of the injector coil. It should be about? Ohms. If it is much higher than this (or open circuit), the injector must be replaced.
Injector driver transistor failure - Check the injector signal coming from the power module (or SMEC). It should rise to about 12V when the injector is off and drop close to 0V when the injector is on. If it is out of spec, you may need to replace the power module.
I measured the volts and am not even close to what they should be so I believe I have a bad power module. I hope this picture off my repair manual comes through it's the same as a Dodge Daytona and yes it is the 2.5. I have to work for a few days and I'm trying to find a used power module to save some money, I replaced the original with the one on the car a year ago because it went bad and it also acts as a voltage regulator for the alternator.
Thanks
JK
Answer -
Hi Joe,
I am glad you are getting to the bottom of this one. On the voltage of the driver wire, did you measure it with the injector disconnected? If not, try it that way and see if it oscillates between O and 12V. BUT then because this pulsation occurs every time the engine rotates a half a turn, unless you had an oscilloscope or similar sophisticated voltmeter I don't believe that you will be able to truly determine that the problem is with the power module (The oscillating 0-12-0-12-0- is going to produce an average reading of something different than either 0 or 12V). My belief is that your fuel injector itself has gone bad. Why not read the resistance of it? It supposed to be around 1 ohm or a little less, but make sure that your digital ohmmeter is zeroed. I know the injector is not cheap, around $150, but that is my best guess as to your too rich situation. Even if it reads around 1 ohm that doesn't prove that it is o.k. Mine failed in that manner.
Roland
Hi Roland:
I checked the volts from the Power Module with the injector disconnected and with the switch on it is fluctuating between .01 and .02 volts and I also checked the resistance on the injector it self and got 1.2 ohms. I replaced the injector after the second failed smog test because I did have it at a good shop last November because I was having a problem with the automatic shutdown relay. They told me then basically the same thing that the injector had not reached its peak voltage. I replaced it with a new one from AutoZone a
GP-SORENSEN I know there are more expensive ones like one from Bosch but I'm still not getting the right numbers from the Power Module. I really appreciate any and all your advice.
Thanks
JK
Answer -
Hi Joe,
One of the two wires to the injector should have 12V on it when you are cranking, compared to ground, and the other one should be oscillating between 0 and 12V (because I don't have the '86 diagrams I can't tell the wire color codes. However I just bought the '86 manual on eBay today so I should know in a week or so if that is necessary to solving this). Thus if there is one wire that is always sitting near 0 and the other one is always sitting near 12V while you are cranking this means that the injector is simply allowing fuel to run out of it continuously rather than in short pulses which is of course why you are getting 900 mV on the O2 sensor and too rich on the smog test and code readout. So if that is the case then I would agree that the injector is probably o.k. and that you need a new power module. That is my best guess, but I have to emphasize it it a guess until I get the wiring diagrams.
Hi Roland:
The cap that goes on to the Injector has + & - on it so if I check while cranking I should get 12 volts on the positive side? Oh by the way I don't know if I told you but the car runs great I just drove it about 40 miles and it runs great and after checking the codes again after disconnecting the battery and letting the computer reset I still get #26 saying injector has not reached peak voltage have to work a few days and when I do I leave it and drive a company vehicle for 3 days so next week I will check the voltage again, and probably buy the Power Module one way or another I will let you know.
thanks again
JK
Answer -
Hi Joe,
Yes the + wire should have 12V when cranking, and the - wire should oscillate between 12V and 0V in synch with the rpm of the engine, one pulse for every half rotation of the crankshaft.
Roland
Hi Roland:
I did as you suggested I checked the voltage to the injector while I was cranking the engine. The meter jumped around a lot the highest was 9. Something down to less then a volt, it seemed the longer I cranked it the lower it went, and I cranked it until my battery gave out. I also unhooked the battery to drain the computer of codes and after driving about 20 miles I did not get another code # 26 ( Peak injector current has not been reached) in fact I did not get any codes. I did do what was suggested on the web site I have been using for help which was Check the wiring and connections to the fuel injector and the power module (or SMEC) and the injector control lines between the logic module and power module. Clean and regrease any corroded connectors with dielectric grease and repair any shorts. When I have a chance next week I will drive it more and recheck the codes and look at the spray pattern which is something I forgot to do today I think that told me more then anything about the to rich problem. The next smog test is free; this is the 6th so I want to make sure it's ready.
Thanks again,
JK
Answer -
Hi Joe,
That is good news that the #26 code didn't come back. I'll keep my fingers crossed that you pass the smog test. That voltage reading pattern seems about right given that there is some lag time between the true value and what the meter makes of it.
I know it seems like a small thing, but lately when one my cars suffers a failed smog test, and i do some troubleshooting with the hope that it passes, and then it does pass, I am a state of bliss!
What state do you live in? I'm in California where when the car gets to be 10 years old it is subjected to a dynamic smog test using a dynamometer. Tougher to pass.
By the way, I just bought a '86 FWD Chrysler shop manual set on eBay and will be getting it soon, via U.S. Postal media mail. So I'll be ready for any other issues that develop with your Laser. By the way, can you give me a brief history of the Laser nameplate? It seems that it had about as many incarnations as the LeBaron, but not always a Chrysler? Were there other models that had the same body? Roland
Hi Roland:
Well I wrote the bottom message Sunday and since then after putting a few miles on the car and running it up in rpm a little the dreaded code #26 has returned, so I will check the voltage again tomorrow and probably order a power module.
Thanks again for answering so fast this is a great service and maybe some how I can repay your kindness with a cold beer. I live in the phoenix area any vehicle that ever had smog on it must still have smog there is a loop hole for the age like mine I have to show I spent $450 on it to get a exemption and then it's only good for 2 years then it must either pass or it's out of here. The Laser is a Body type G it's the same as a Daytona and I believe the first year it was made was 84, if you out minimopar into your search engine or Google you will find a great web site with many links to it. I spent 12 years in SanDiego and I might be heading there this week depending on the car ha-ha. My wife and I have tried to keep the car in god condition it gets great mileage and has a lot of bells and whistles and yes I have seen Lebanon's that have the same type of on- board monitoring systems as mine. About 15 years ago I owned a Super Comp dragster and had a blast with it and I must admit I've had dreams of a small block in the laser body. I spent 25+ years as a welder/fabricator and have a garage at my house begging for the project. Back to business, I have a 96 neon and when I take it in for smog they just plug into the computer and ask it if it's having a nice day take my $27.75 and say see you in two years, The Laser they put on a dynometer and run it up and down the little computer map for about 5 minutes, if you have ever seen Phoenix on a ozone warning day you would understand why LA's bad but were not far behind. I do not know how this graph I'm trying to add will come through but for sure check out the web site minimopar.knizefamily.net/ some more guys I definitely owe a few beers please try to find the link to his personal website it is on the home page I guess I'm not the only 2.5 freak out there, I will be in touch and thanks again.
JK
Body Years Vehicle Models
A 1989 - 1993 Chrysler LeBaron, Dodge Spirit, Plymouth Acclaim
C 1988 - 1993 Chrysler New Yorker, Dodge Dynasty
E Chrysler New Yorker Turbo, Dodge 600, Plymouth Caravelle
G 1984 - 1990 Chrysler Laser, Dodge Daytona
H 1985 - 1989 Chrysler LeBaron GTS, Dodge Lancer
J 1987 - 1993 Chrysler LeBaron (2 door, not K-body)
K Chrysler LeBaron/Town & Country, Dodge Aries, Plymouth Reliant
L 1979 - 1990 Dodge Omni, Plymouth Horizon (4 door)
L* 1981 - 1987 Dodge Charger, Plymouth Turismo (2 door)
L** 1981 - 1987 Dodge Rampage, Plymouth Scamp (2 door pickup truck)
P 1987 - 1993 Dodge Shadow, Plymouth Sundance
Answer -
Hi Joe,
'Sorry to learn of the the return of the #26. Are you certain that the injector pattern looks normal (fine spray, no after drip at shut off)? It may be that its O-rings are leaking or that the injector is not functioning properly.
But let me know whichever way you solve this one.
Our system in California sounds very similar to yours. Fortunately no intractable issues with my '89 2.5L non-turbo. And the older 2 cars of the fleet are now grandfathered at 30+ years so I don't have to hassle about them. Thanks too for the plaudits and offers, if you come to the Bay area let me know. And thanks for reminding me of the resource of the Russ Knize's site and the breakdown by body code.
I hope that the '86 manual set will arrive this week and I'll look into it for any insights on the 26 code. The air filter isn't clogged, perhaps?
Roland
Hi Roland;
Well I spent the afternoon putting a new power steering pump on because the other one was leaking bad I also rechecked the wiring and tested the voltage again at the fuel injector. It's pretty hard to determine what's going on because it jumps around so much but I never do get the 12 volts I'm supposed to get an with the key on (not cranking) I only get 1.40 volts. When you look in the throttle body at idle or even when you give it some throttle the fuel is just running in almost like a hose but when I drive it the car seems to start and run fine, but I know that does not mean any thing and smog test results do. I guess I'm reluctant to take it in and put it on a computer because I think they would just charge me $80.00 and tell me it needs a new power module when I can spend $100.00 and just buy the thing. My? For the day is there anyway or any one who can test the power module of the car? Or do you think I should just quit screwing around and just buy one. I thought I would send you the exact read out from the smog dudes;
LASER APPLICABLE STANDARD
HYDROCARBONS (HC) IN GRAMS/MILE 0.67 1.60
CARBON MONOXIDE (CO) 21.91 15.00
OXIDES OF NITROGEN (NOX) 0.69 2.50
Thanks
JPK
AnswerHi Joe,
I just had another idea: could the fuel pressure regulator be defective and allowing too high a fuel pressure in the system? If you have or can borrow a pressure gauge that would be good to check. I don't have the '86 manual yet and the pressure for the FI system changed between '85 and '87 but I can't be sure which it is for your '86.
Roland
Hi Joe,
The readings confirm that the mixture is way off. And your observation of the gas pattern at the throttle body also confirms that. My inclination would be to try and get new o-rings for the injector and install them. If that doesn't change things, then I would buy a new injector (or if the part number for your '86 is valid for several model years of the 2.5L engine then you might have a good shot at getting a working injector out of a wreck.) I bought a new one for my '89 2.5L and although it cost $150 it solved a problem of an injector with a very sloppy/sloshing looking pattern. If the injector in there now is original, then I would be even more inclined to replace it. I would not place too much faith in the voltage measurement you are trying to do at the injector. For if it only read 1.4V while the other post read 12V (the supply voltage from the ASD relay) the injector should be spraying gas. I suspect that there is a voltage divider-misreading of that voltage by your meter due to the low impedence of the injector coil. I can't be sure, of course, but that is my inclination. You have the vehicle there and are more familiar with it. I don't know how much you are going to have to pay for a power module compared to the injector, but if you can get it for a lot less than $150 I suppose it would be worth a try.
Keep me informed of what happens.
Thanks,
Roland
