Camshaft position sensor?

Backfires out intake. Engine light is on. Fuel pump is working.

Well, I did that and got a cam pos sensor fault. I replaced the sensor with same result. Have not checked it since changing out the sensors but I will soon.

Yeah ill have it tested. It'll probably end up in the shop, lol. I'll let you know.

I'm hoping someone can help with this, it's driving me crazy. My wife's car has had intermittent issues since a few years ago, we drove it down to FL from Ohio. The car was missing and blowing white smoke, we took it to a mechanic spent $300 to replace plugs/boots/coil pack. Still had a problem. So I took it to a dealership, they said the battery was low so they replaced it along with another part(factory recall) and the car magically ran fine. It has ran fine for the last few years with an occasional cough, until recently. It was running terribly, I rented an OBD which read only one code p0300(multiple ore random cylinder misfire. So I pulled the plugs lets call the farthest drivers side plug #1 and so on down the line. Plugs 2 and 4 looked different bought new plugs and ran it for a bit, pulled them again and again #2 and #4 came out clean and wet. I checked everything out, "borrowed" a coil and an ignition control module from the parts store. No change, I inspected the boots that act as wires and they are in excellent shape. I've had the parts store check the map sensor, cam shaft position sensor, crank sensor, ignition control module, and coils, all tested fine. I've unplugged the o2 sensor and the maf sensor, zero change. I kept hearing a ticking sound, so I thought electrical, on a hunch I went to the parts store and bought a new coil pack thinking somehow the wires inside the pack were shorting out, plugged it in. Ran fine. For about two weeks. Now the missing isn't nearly as bad, and it is now only plug#1 that is wet and clean. Since it is just one plug AND a completely different plug then it has been, I was thinking maybe the new coil pack is grounding somehow to the engine block, but it's black and I don't see ANY signs of carbon tracing. Tonight i'm renting the OBD again to see what it says. I've also done compression tests, all cylinders read the same. This is something to add, the day I got the new coil pack I had the camshaft and crank sensors out, but put them right back in before I put the new coil pack, could it have been the cam sensor? I notice when I unplug it( when the car is running badly) there is no difference in the way the engine runs, which is troubling. I apologize for this being long winded and possibly random, but I'm trying to remember every detail. Thanks in advance, Chad

Alright, last night I hooked up the OBD and got p0304 cylinder 4 misfire. I've been driving it, because I don't want my wife to, and the problem is very random. Yesterday the whole way to work and almost the whole way home(30 miles) the car spit and sputtered, but I was getting on it trying to see if maybe that might help, and it seemed to run a little better from it. I put some fuel injector cleaner in it on an empty tank last night, today it ran a lot better, only coughed a few times, but still coughed a few times. There was no difference in the kind of day(the humidity levels have been about the same) and last night my gas tank was almost empty when I put the injector cleaner in, then I drove to the gas station and put about half a tank in. It seems highly unlikely that an injector could have gone bad immediately after this electrical issue, but possible I suppose.

So, I've been dealing with this issues for a few years, but it has gotten worse. The car will start and run, but then it will randomly drop the RPM's by about 50-100 and feel kind of like it is misfiring. For a long time, just keping the RPM's above 1000 while idle would keep it from dying, but now it will die frequently. I've replaced both the crankshaft position sensor and the camshaft position sensor. I've replaced the timing chain (I read somewhere this can happen from a stretched chain), Ignition control, plugs, boots, and coils have all be tested. Fuel filter and catalytic converter have been replaced as well. When it first started happening I took it to a Chevrolet dealer and they replaced a few things and then they told me I need a new engine (this was 4 years ago). It passed safety and emissions for 4 years after, I find it hard to believe that it could be the engine or reluctor wheel if it has been running for that long. Any ideas on what else to try?

Thanks

Yeah, is the a specific reading I should get? Or just look for a common reading among all of them? Where/what is the best place to test them?

2.4 are nightmare motors but it really sounds like a iac motor problem. "Idle air control" its located in the side of the throttle body any car that the rpms drop that low will misfire and run terrible. There pretty cheap and will need a small torx bit to change. Also while you in there grab some carb cleaner or intake cleaner and remove all the carbon build up for the new sensor to read better.

Alright, I checked the injectors, all of them seem to be reading about the same resistance. I did notice that it seemed like the numbers were all over the place, then i'd get a good reading, then all over the place again. Maybe the connecter on the injector is loose? But I started the car after the testing and it runs perfect, the whole way to work, not even a single sputter. I know it's something stupid, like a loose wire.

Sorry, I was at work and decided I would try posting the question and didn't have the codes in front of me. They are p0335 and p0341.

It dies both at idle and when driving on the highway. Although currently it dies too much for me to get to the highway. It doesn't die until it has warmed up some, it does fine while it is cold.

Could this be from exhaust back pressure? I changed the catalytic converter a little over a year ago, but the muffler is original and fell and broke the flange last year when the hanger bracket rubber failed.

Crankshaft position sensor checked out okay on electrical tests I'm able to perform. I don't have a scope so I only checked resistance and signal voltage.

Thank you for the help.

I cleaned the iac and it still acts the same. It's there a process for checking the iac?

Thanks