My car started skipping on cylinders 1 and 4 so I replaced the plugs and wires. It made no difference. When I removed the plugs they were wet with gas, even though the spark seems very strong. Assuming I had leaking injectors, I paid big bucks to have the injectors replaced. It made no difference. It’s still skipping. The mechanic wants to try replacing the distributor. That ain’t cheap either, and I’ve already spent more than the car is worth. The mechanic still has the car, but it seems like he’s baffled. He’s had it going on two weeks now. Should I let him replace the distributor? What else could it be?
We had one of these at one time and I would like another one . So I hope you find a mechanic that can solve the problem . You may have to even call a Mazda dealer .
This needs to be definitive. You need to know whether or not you have sufficient spark. Then you need to know if the fuel pressure is at spec. Then you need to do compression test.
There’s a fairly simple fuel pressure test to verify leaking injectors, hopefully that was done before replacing them. An ignition system analyzer would tell you if the distributor was a problem or not. Suggest you have that test done before popping for a new distributor. If you want to replace parts, a basic tune up makes sense. New plugs, distributor cap, ignition rotor, high voltage wires, engine air filter, valve clearance check (if applicable), ignition timing, and compression check. Check for any diagnostic codes of course. If you want to try something simple, observe the engine compartment as it idles in total dark. See any sparks jumping around?
The fuel pressure test seemed like a great suggestion but the mechanic said he already did that. He says it’s ok. He still thinks it’s the distributor, even though the sparks all look hot as a welding machine arc when I saw them. He pulled all the plug wires out of the distributor one by one. They all produced a spark an inch long. He then removed the spark plug from one of the bad cylinders and laid it on top engine. Then he started the engine. I almost needed sunglasses to look at the spark. But he says there’s wear in the distributor shaft with too much “run-out”. I don’t understand why run-out is important if the sparks are good. I don’t know if he has an ignition analyzer, but that would be great test to run.
At this point the mechanic says he’s going to take another look at it. He’s been in business for many years so I feel like he should know what to look for. But he already gave the car back to me once and said it was fixed. And when I left his shop it was running perfectly. But after I’d driven about a mile it suddenly started skipping again. I took it back to the shop immediately.
@Tester You can tell I am old. I always thought leak down tests were harder to do and more expensive. The article was insightful. It said that 20% or less indicates good. Do you agree, and Ball Park figure what would a good gage cost?
hmmm … it might have to do with the ignition advance function. the spark problem doesn’t show up at idle, but when the ignition advance kicks in, then maybe it showing up. the distributor’s job is to route the hv spark outputs from the coil to each of the spark plugs one by one at the time needed. if the distributor rotor (that thing on top of the distributor shaft) is misaligned with the copper contact on the circumference of the inside of the distributor cap, then you might get a misfire, and excessive run-out could cause that I suppose. you’d think there would be visible carbon tracks on the inside of the dist cap if that were happening though. the bottom line however is if the distributor run-out is out of spec, that has to be fixed in any event, so might as well do it first, in case it is the cause of the symptoms.