QuestionThe codes reported are 12 and 55, battery disconnect.
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Followup To
Question -
Hi Roland,
Four months ago my waterpump seised up and broke the timingbelt on my 94 Chryler LHS 3.5L engine.
I have just replaced the pump, belt, and tensioner.
The engine now idles smooth for 2 minutes and then starts to fluctuate up and down from 500 to 1000 RPMs for another 2 to 3 minutes until it it finally dies out.
The gas is 4 months old and the camshaft sensor was loose and I tighten it.
I read that the spacing for the camshaft sensor is critical, but can not find any specs for the spacing.
Do you know what the specs are?
and could this be why the idle is flustuating?
or is it something else?
Ps: it dies out when I come to a stop.
Answer -
Hi Don,
I haven't seen a specfic spacing spec. Evidently when the sensors are new, they are supplied with a paper on the tip which is 'sacrificial' in that you install it with the paper surface touching the sprocket and then you tighten the retaining bolt to 105 inch-pounds. The paper provides the proper spacing and it wears away, leaving the proper gap. You can also check it electrically according to the Chrysler and Haynes manuals I have. The voltage signal for the camshaft sensor measured between the tan/yellow and the black/light blue wires should alternate between 5.0 volts and 0.3 volts, fluctuating as you rotate the engine by hand or by tripping the starter without actually starting the engine. So if you are getting that sort of reading then you can assume the spacing is o.k. To get the reading, use a very fine needle to pierce the insulation of the wire just so you can hit the conductor within by means of the pin tip. Attach your meter leads then to the straight pins so positioned in the two wires. Similar alternating voltages should be seen between the light blue/dark blue and the black/light blue wires of the crankshaft sensor.
My thoughts on the dying out and idle variation are that it could be more related to the mixture than to the spark. One useful thing to do is to see if any fault codes have been stored in the engine controller memory. Try using the ignition key: turn it "on-off-on-off-on" and leave it "on" (doing this quickly, no longer than 5 seconds). Then watch the 'check engine' light to begin flashing, then pause, flashing, pause, etc. Count the number of flashes before each pause and keep track of the numbers. Repeat the readout and verify the counts are correct. Then group them in pairs in the order that they came out, thus forming two digit numbers. You may notice that the pause is shorter between the digits of a given number, and longer between the numbers themselves. Then send me a 'follow-up' question telling me the results of your readout. By the way, 55 will be the last number (two groups of 5 flashes each) and that is the code for "end of readout".
For example, the coolant temp sensor may not be reading the change in operating temp and thus the mixture may not be set for that situation. (That would be a code 22) So, let me know what code numbers you find. There is a decoder list at:
http://www.allpar.com/fix/codes-html
but you may want to get some more specifics as to how to respond to a given code, so feel free to ask me.
Roland
AnswerHi Don,
Sorry there is nothing relevant in the codes, unless the 12 were telling us that the battery clamp/post interfaces are not conducting very well and need to be cleaned.
Because of the 4 month old gas and the condensation that occurs in winter times, you might try putting some gas additive in the tank that disperses water.
When it dies, have you checked for spark?
Did you check for the voltage output variation values (0.3 and 5.0V) on the cam and crank sensors after the die out?
'No code-no starts' are always troublesome. It may be something more subtle than can be recognized by the engine controller and thus needs to be read with a full blown diagnostic testor that a sharp tune-up person can recognize as an off-value sensor reading.
So give those a try and let me know.
Roland
