Question-------------------------
Followup To
Question -
My wife's 1994 Chrysler New Yorker won't start in wet conditions. It will turn over and chug now and then like it wants to start. Once or twice (out of a dozen or so times) I pumped the accelerator and then held it to the floor while turning the key and got it to start, but it ran very rough and I was only able to limp it into the garage to dry out. Once it dries for a bit, it starts right up and runs great. Any ideas where to start looking?
Answer -
Hi Bruce,
The most likely reason for the problem is that the high tension (spark) side of the ignition system is suffering a breakdown due to increased arcing from the spark wires to metal parts of the engine nearby. If the spark wires are the originals that came when the car is new now would be a good time to replace them. You may be able to see the "light show" if you open the hood while the engine is idling on a humid evening in dark ambient light conditions.
There are other checks that would be worthwhile. You will note that there a 3 pairs of spark plug wire towers at the spark coil. The resistance between the center contacts of each pair of towers should be in the range of 11,500 to 16,000 ohms. The wires themselves also have resistance built-in to reduce radio noise. So verify that the wires read between 3,000 and 12,000 ohm per foot of length when you measure between the ends of the wires. There is no specific test for insulation breakdown except the arcing "light show".
It is also possible that there is a poor connection somewhere in the low tension circuit. A good way to find that would be to ask the memory of the engine controller if it has recognized any 'fault' codes and stored these as two digit numbers. You can do this yourself. 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 which will be illuminated 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". Let me know if you get any codes other than 55 and I will give you some corrective action suggestions.
Roland
The only code I got, besides the final 55, was 12. In the Haynes manual, this code says the battery had been disconnected during the last 50 key on cycles, but I haven't disconnected the battery for quite a while. I DID notice a lot of corrosion/build-up on the positive connection on the battery, so I'm going to clean that. Tomorrow, My brother and I are going to put in a new set of plug wires, platinum plugs, and check all wires and connections. I'll let you know how that goes. Are there any specific ground wires or sensor connections (crankshaft sensor, camshaft sensor..etc) that might cause this problem when damp? I appreciate all your help.
Bruce
AnswerHi Bruce,
Cleaning both battery terminals and applying anti-corrosion compund to the terminals and clamp interfaces is a good idea. A poor connection to the battery could cause a code 12, because it really can be set by a volt drop rather than a complete open of the circuit.
Other grounds to check: follow the negative battery clamp major cables to whereever they terminate, and look for the possibility of a wrap around cable clamp to the body somewhere along the cable path as well. Then check for an engine ground connection to the rear of the front bank of cylinders. And another ground strap on the rear of the transmission. There maybe be body grounds for system wires, located on both shock towers. And I notice that there are supposed to be a couple of helical shields with light weight (18 ga) black ground wires, on the harness that runs from the controller to the igniation coil pack. So try to verify those. That would probably handle that side of the question. I doubt if there is a problem with the timing sensor grounds as those are well encased and routed directly to pin 4 of the powertrain plug. But it looks like there is a multi-pin connector for both sensor signal wires and the ground wire somewhere near the engine that might be worth disconnecting and spraying the inside contacts with electrical contact cleaner. There is one ground on the ignition switch, a black wire on pin 2 that probably grounds to one of the instrument panel support brackets under the dash, so look for that wire to be coming out of the steering column.
I think your approach is sound and will solve the problem.
Roland
