We have a '93 Grand Am that is not passing emissions testing. We replaced the O2 sensor, per the error code on the diagnostic machine. Still had problems. We asked a neighbor who is a mechanic what the problem could be and he suggested replacing the coils, which we did. Still had the problem. We took it to the dealer who diagnosed it as bad coils/coil housing/boots. We replaced the coils again as well as the housing and boots. It ran fine for about 30 minutes and now the problem is back. We took it in again to a State inspector who again diagnosed the coils. Again, we replaced the coils. Same problem. The mechanic called his supervisor who said that maybe it was the crankcase position sensor, which we just replaced and still have the same problem. Does anyone know what in the world could be the problem. We have spent way too much time and money on this car but we have to get it up to emissions standards in order to renew the registration. Please help!! Thanks!!!
How about the ignition control module ? I like this crankcase position sensor !!!! It's the crankshaft position sensor . What engine ? 2.3 or 3.3
SOURCE: cylinder 3 misfire
Make sure you're using the recommended spark plugs. When my car did that, I had put Bosch Platinum Plus-4 plugs in and got that same problem. Turns out the plugs are too hot and cause it to fire prematurely and kick the misfire code.
SOURCE: Car not running on all cylinders
the first thing that comes to mind is ignition system faults. Are the spark plug wires connected properly, in the right firing order? Has work been done on the distributer, or the engine head, recently? Ignition timing can be 180 degrees out, and the engine will still run, sometimes. If it is not the ignition system, the next most likely culprit is the head gasket, which seals the head to the block of the engine. If this gasket is breached seriously, it can cause a cylinder(s) not to fire. Is there water in the oil, as evidenced by a thick, white foam? Is there oil in the coolant? Either of these are symptoms of a leaking head gasket.
Basically, one cylinder isnt firing for one of a number of reasons. The most common cause is an igntion fault. This will cause the engine to feel and sound "lumpy", and the power would be greatly reduced. The best way to find the cylinder which is responsible is quite simple but care must be taken. Firstly if you hate electric shocks as much as I do, find a proper pair of electricians insulated pliers, and even some decent rubber gloves if you can aswell. Start the engine, and one at a time, use the pliers to remove a lead from the top of one spark plug, if the engine almost stops, or gets worse in any way, it is not that piston which isnt firing. Repeat the proccess, one at a time, you will know which piston ISNT firing when you remove the plug lead, and there is no change in the engine sound, this is your defective cylinder. Its just a case then of looking at the condition of the spark plug and asessing the cause of the misfire before carrying out repairs. BEWARE:- THE LEADS WHICH CONNECT TO THE SPARK PLUGS CARRY SEVERAL THOUSANDS OF VOLTS - HENCE RUBBER GLOVES AND INSULATED PLIERS
SOURCE: po300 code, replaced 1 crank sensor needing to know voltage on se
Resistance check the coils. Check for spark on all 6 cylinders.
SOURCE: Engine code states cylinder 2 misfire. Replaced
sounds like a bad injector, just connection at the injector, also check for leaks at intake, one more thing , do a compression test on that cylinder start there, good luck.
SOURCE: i have a 99 grand am SE 2.4 4 cylinder and my
A misfire doesn't always have to be ignition... it's just the most common cause. Faulty or plugged injector, low compression. You need to check fuel pressure and test the fuel injector flow. Then check compression. If you don't have tools for these tests, take it to someone who does. Testing is much cheaper than throwing parts at the problem.
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