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Question -
diagnogstics say i need to change ignition sensor. where and how is my question. i have chgd an o2 sensor before... can you help me save 500 $ it runs rough, coughs spits dies backfires etc
Answer -
Patricia,
There is normally a "code" number associated with the fault. Did someone state a trouble code number like example code #41 or #42 ? The reason I say this is, an "ignition sensor" is a more general description of likely an "ignition module" or a "crank (crankshaft)sensor" so there are at least two possibilities. The ignition module is located under the ignition coils
and the crank sensor is located on the engine block. The diagnosis given to you sounds likely however unless verified its likely just an educated guess on the shops part. If you can tell me more I would be able to help more. I would also like to know is the engine computer is located in the engine compartment? I would make sure I found out this because its important.
John
ignition module is what i meant. i asked for a copy of the readout, but i have to go back to town to get my car looking at my ols 88 I can't find which would be a module . wires do plug into the coil pack itself but I'm sure thats not it. well it gives me a general idea. I will head to the library to copy a diagram. thank you for your help. i am glad you all are there!1 patti
AnswerPatti,
I just took a look to refresh myself and realized the module is on the side to the engine block. This style is the hardest to access. Truly unless you are a natural contortionist magician there not much chance of accessing it. I not playing the man/woman card here its hard for any tech in the business. I will say this for sure, "unless they are 100% sure its not likely your problem" This is one of the hardest things to diagnosis. No kidding here. Everything you said about how the cars symptoms but stalling point to other likely suspects. The misfiring/popping/backfiring all are more likely connected to the spark plug wires and or spark plugs on that engine package. I have trouble shot hundreds of these and have found the plus and wires is #1, #2 is the engine computer and #3 is one of the coils. Some where in the first 3 is the crank sensor. The module is always the last thing to cause this. This is from years of drive-ability work at a dealership level, which is far more intense than the normal independent shop environment. All I did was General Motors computer controlled fuel and ignition systems.
Before I did anything I would look to see if the computer is under the engine hood. It might be next to the coolant reservoir on the passenger side of the engine bay. It's under a plastic covering. I would have the tech expose it and with the engine running slap the side of the computer hard enough to sting his/her fingers or use the handle of a screwdriver. Do this numerous times looking for the engine to falter while its being slapped. The computers often encounter internal cracks in the circuits which will cause the engine to spit backfire stall most everything in the book but run good all the time. If the engine reacts negatively then replace the computer and likely your up and running.
Then I would, Second, make sure the spark plug wires have been changed in the last 6 months along with the spark plugs. If there not new I would do this first. Its not easy but that's my personal opinion. The module just doesn't support your symptoms as a first option.
John
