stock heads, two. some aftermarket heads are made for 4.
how do you change the spark plugs on a 1991 q 45 infiniti
There are four spark plugs on each side of your 1991 Chevrolet engine. The spark plugs will be near the bottom of the engine.
under the dash between the tank halves.
In the engine... If it is a a straight six. They run in a row. follow the spark plugs wires to them.
You only set the timiming for engines with spark plugs, and diesels don't use spark plugs.
The 1991 Mercury Marquis spark plug gap is .034. Most spark plugs will be pre-gapped by the spark plug manufacturer.
.031 in
0.35
.060"
To change the spark plugs on a 1991 Toyota Camry, first, ensure the engine is cool and disconnect the battery. Remove the spark plug wires by carefully pulling them off the plugs, then use a socket wrench with a spark plug socket to unscrew and remove the old spark plugs. Check the gap on the new plugs and install them by hand to avoid cross-threading, then tighten them with the wrench. Finally, reconnect the spark plug wires and the battery.
The first 3 spark plugs to the right are easy to change,the one on the left you have to loosen up the alternater to get to.
To change the spark plugs on a 1991 Toyota Camry, first, ensure the engine is cool and disconnect the negative battery terminal for safety. Remove the spark plug wires by gently twisting and pulling them off the plugs. Use a spark plug socket and ratchet to unscrew the old spark plugs, then install the new plugs by hand to avoid cross-threading, followed by tightening them with the ratchet. Finally, reconnect the spark plug wires, ensuring they are secure, and reconnect the battery terminal.