Engine with ‘zing’ is not necessarily a good thing

Hey there, time traveller!
This article was published 22/08/2003 (8251 days ago), so information in it may no longer be current.

QUESTION — I drive a 1986 Nissan Maxima and I am having trouble with the starter.

It used to “zing” (like the sound when you try to start the engine after it is running) when I started the engine. I took it into the dealership and they replaced the starter drive and ring gear. The car worked fine for a few months, but now it is doing it again. It can take several tries before the engine will crank. The mechanic has even made shims to move the starter away from the ring gear but the noise still occurs. What can I do to repair my car?

ANSWER — The “zinging” sound you hear is coming from the starter drive as it is being moved into the ring gear as you start the engine. A burr on the teeth of the starter drive or the ring gear may be preventing the starter from engaging properly. Replacing the starter drive and ring gear is the usual repair for this type of problem, but you may have another problem as well: the position of the starter in relation to the ring gear.

Your mechanic was on the right track when he used shims to correct the starter alignment. Usually shims are not needed, but occasionally manufacturing tolerances make them necessary. As a rule of thumb, about .060 of an inch clearance is needed between the gear teeth for everything to work correctly. This is about the diameter of a paper clip wire. The starter drive clearance is adjusted with the shims until the paper clip will just fit between the gear teeth when the starter drive is in mesh with the ring gear.

Adjusting the clearance after burrs have been formed on the ring gear teeth usually does not work. Usually the starter drive and ring gear will have to be replaced again. When you inspect the ring gear, you will only find the teeth worn in three spots. This happens because typically a six-cylinder engine (as found in your Maxima) stops in only three places. The wear occurs in only these three places when you try to start the engine. You are on the right track for repairing your car, but need to start by replacing parts again!

QUESTION — I took My Mazda B2200 truck into the repair shop for a new distributor cap and rotor, and to have the timing set. They told me they could not tune my engine by adjusting the spark plug gap because I had installed platinum tip spark plugs and new plug wires myself. They adjusted the timing but now the truck doesn’t start as well as it did before I took it in!

The old worn spark plugs had a gap of .044 inch. The new platinum plugs were gapped at .031 inch, which is the correct specification for my truck. Should I gap the platinum plugs to .044 inch to make it start better, or is something else wrong?

ANSWER — The gap on your spark plugs should be set to factory recommendations: .031 inch. Platinum spark plugs have the advantage of longer plug life and less voltage required to fire them compared to regular spark plugs. Their disadvantage is a higher initial cost. The cause of your truck’s hard starting is not related to plug gap. As long as plug gap is close, it will have little effect on normal passenger vehicle use. Your truck should run as well on platinum plugs as it did on the original equipment regular spark plugs. Something else must be wrong.

I would suspect ignition timing or fuel delivery. Your truck was starting fine before you took it in for repair, so timing is the most likely suspect. Recheck the ignition timing as a starting point. If you are still having problems, a good mechanic should check out the engine with an engine analyzer to determine if all cylinders are firing correctly. Too often I have seen new spark plugs that were cracked during installation or spark plug wires that look perfect on the outside but are broken inside. Either fault could cause a hard starting condition.

Jim Kerr is an experienced mechanic, instructor of automotive technology and freelance journalist. You can e-mail questions to Jim at the address below.

kerr.jim@sk.sympatico.ca