Symptoms of Bad Distributor Timing – Causes and Resets

Although distributor ignition systems are no longer in use today or even in the last 25 years, if we go back to the 80s and earlier, they were pretty much the only option, and while they do work wonderfully, they do have a lot of moving parts which means a lot can go wrong, including ignition timing which is pre-set manually.

The main symptoms of bad distributor timing include engine pinging, high fuel consumption, poor performance, difficulty starting the engine, engine shaking, and backfiring.

how to fix late ignition timing

What Causes Distributor Timing to Become Off

As we mentioned, the ignition distributor has a lot of moving parts, and some of them can wear out. The distributor essentially has a lobe shaft that looks a lot like a camshaft, and it’s also driven by the crankshaft. Those lobes push on contact points that close the circuit for each spark plug individually and fire it at the correct time.

As those lobes and contact points wear out, they will affect ignition timing significantly, but that doesn’t happen too often. What’s more likely to happen is that a faulty distributor cap or the distributor housing becomes somewhat loose over time due to engine vibrations and turns in one direction or the other.

Since that’s how you adjust ignition timing, it will either advance or retard timing randomly. All ignition distributors also have a vacuum line that adjusts the ignition timing continually as you drive according to engine load or intake manifold vacuum. The vacuum line is a simple rubber hose that can crack as it ages and completely disable ignition timing adjustment.

That same vacuum system relies on a spring valve and centrifugal springs inside the distributor. If any of these components fail, the ignition timing will become erratic and cause all the symptoms we will talk about shortly. But in the end, distributor-based ignition systems need to be readjusted every 10,000 miles, so before jumping to any conclusions, manually adjusting the timing should be the first thing you do.

What Are the Symptoms of Bad Distributor Timing

Symptoms of bad distributor timing are much the same as misfire problems in modern vehicles, only in this case, you don’t get to scan the fault codes because OBD2 wasn’t a thing back then. Also, a lot of these symptoms are the same as symptoms of a bad distributor rotor and other ignition system components.

That’s why without severe incorrect timing symptoms, you will have to rely on your senses to figure out if distributor timing is bad. But you can also use a timing light and remember that distributor adjustment should be made at least every 10,000 miles. Also, you will

Engine Pinging

Engine pinging, also called detonation and spark plug knock happens when ignition timing is too advanced. In other words, when the spark plugs fire too early. Pinging sounds like metallic clicking, but it’s very faint and difficult to notice unless you pay attention. But you should pay attention if you suspect bad distributor timing since pinging can crack the pistons and destroy the entire engine.

High Fuel Consumption

Excessive fuel consumption is mostly a result of retarded ignition timing (when spark plugs fire too late). Under such conditions, a lot of the fuel going into the cylinders doesn’t have time to burn and make power and instead gets the exhaust pushed out. In other words, that’s pretty much pumping fuel into the exhaust and results in noticeably higher fuel consumption.

Poor Performance

Advancing the ignition timing is the first thing modern tuners do to extract more power from an engine, so it can’t result in poor performance. But retarded ignition timing most definitely will, in part because, as we already mentioned, raw fuel gets pushed into the exhaust instead of burning inside the cylinders.

Difficulty Starting the Engine

Starting a cold engine requires a lot more fuel or a richer air/fuel mixture which is why most older vehicles have a manual choke. And with retarded ignition timing, by the time the air/fuel mixture reaches maximum pressure, the exhaust valve opens, and all is lost. As a result, you will find yourself cranking the engine a lot longer than usual and possibly even unable to start it at all.

Engine Shaking

In case the ignition timing is severely out of adjustment, the vehicle will shake violently at idle or when trying to accelerate. That’s because some cylinders will not be firing at all, or all cylinders will intermittently stop working. That can have a lot of negative consequences for an engine, and if you notice a symptom like this, it’s best to avoid driving the car until you fix it.


Backfiring is an obvious symptom of bad ignition timing and bad distributor adjustment, more specifically retarded ignition. We already mentioned that a lot of unburned fuel goes into the exhaust when the ignition is retarded. Combine that raw fuel with extremely hot exhaust, and it will ignite as it comes out of the tail pop and make loud pops and bangs and possibly even shoot flames.

can a bad distributor cause loss of power

How to Reset Wrong Distributor Timing

To reset the wrong distributor timing, you first need to locate the crankshaft pulley and make sure you have a clear view of it. Then, find the ignition timing degree tab bolted to the engine block and sitting right above the crankshaft pulley. You can check out the video below to see what that looks like.

Then, you need to remove the vacuum line from the distributor and plug it in with a screwdriver or whatever you have lying around that will make a good seal. Next, get an ignition light. You can buy them at auto parts stores for about $20 to $30.

Now you want to attach the timing light cables to the battery and the clamp to one of the spark plug leads. Make sure none of the cables are hanging into the engine bay, and start the engine. Point the light at the crankshaft pulley, and wherever the mark on the pulley falls relative to the timing degree marks on the engine block is your current timing.

To adjust the timing, loosen the distributor cap or housing depending on the model, and turn it clockwise and counterclockwise to adjust. You can do that as you are holding the light to see in real-time what’s happening with the timing as you adjust it. You also want to check your owner’s manual to see what the correct ignition timing is for your specific model.

Alternatively, you can have a professional adjust the timing so you avoid having to spend money on new tools and possibly workshop manuals. Distributor timing will set you back somewhere between $50 and $100 and takes about half an hour to do.

Also, here is a video of the whole distributor adjustment process.


What will happen if your distributor timing is off?

If ignition timing is slightly off, there won’t be any negative consequences for the engine, at least not in the first 30,000 miles or more. But severely bad ignition timing can cause carbon build-up and more stress on other components to the point where it could destroy the engine.

Can a bad distributor cause timing issues?

A bad distributor can cause timing issues, but it’s unlikely. A bad distributor will most likely cause no spark and no start while, but the vacuum advance system sitting on the distributor can cause timing issues.

What are the symptoms of over-advanced timing?

The two most noticeable symptoms of over-advanced timing are stalling and poor idling, but that happens only in extremely severe cases. But even slightly over-advanced timing can cause pinging, which can cause catastrophic engine failure.

Will distributor timing cause no start?

Distributor timing is unlikely to cause no start. Distributor timing will only be so bad if you install it incorrectly or if something inside the distributor has failed. But it can make it much more difficult to start the engine.

Can bad distributor timing cause no spark?

Bad distributor timing won’t cause a no-spark condition. Bad ignition timing means the spark plugs are still firing but at the wrong time, which can cause no start, but the spark will be there.

Can distributor timing cause a backfire?

Bad distributor timing can most certainly cause a backfire. If the ignition timing is too retarded (spark plugs fire too late), a lot of unburned fuel will enter the exhaust, and if the exhaust is hot enough, that fuel will ignite as it nears the tailpipe and make a backfire.

Final Words

In the end, even slightly bad ignition timing will cause some symptoms that you can pick up, and since over-advanced timing can completely destroy your engine, you should not take the matter lightly. Not to mention you will fail the smog test, and the fuel consumption will be significantly higher.

Some other symptoms you may notice include backfires, poor performance, and difficulty starting the engine. And if you notice that the vehicle is shaking and vibrating at idle or when trying to accelerate, it means one or more cylinders are not firing, and our best advice is to stop driving the vehicle until you fix it because you can cause even more damage.


Ibro Cehic

From a young age, I was captivated by cars and motorcycles, and my first driving experience only fueled my passion further. By the age of thirteen, I was already tinkering with vehicles and knew that my life would revolve around them in some way. Combining this passion with my love for writing, I now share my automotive expertise with fellow enthusiasts through my articles.

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