1985 Monte Carlo SS Tune Up - 1985 Monte Carlo SS

The correct way to gap a plug is to lever the electrode to the proper gap. The correct plug is the Delco R45TS. We gapped 'em at 0.035.
The correct way to gap a plug is to lever the electrode to the proper gap. The correct plu
The distributor cap wears in the same manner as the plugs. As the parts age, the gap between the rotor and the terminals increases and repeated heat cycles crack the cap and cause random misfires. The coil (right) needs to be swapped on the new cap. A quick check of the primary terminals (red and yellow wires) and between the yellow wire and the secondary terminal (the button under the coil) with an ohm meter can determine if the coil is OK. Primary resistance should be low (MSD recommends 0.31 ohm for its in-cap coils), and secondary should be high, 9,000 to 11,000 ohms, but not infinite.
The distributor cap wears in the same manner as the plugs. As the parts age, the gap betwe
When replacing the coil, we've forgotten to add the ground strap more times than we care to remember. Note that the coil button goes under the rubber grommet.
When replacing the coil, we've forgotten to add the ground strap more times than we care t

There are two different coil heights, so if your cap and rotor come with a new set of screws, they might be too long for the original coil. The best bet is to use the original equipment or risk punching through the cap (pen points) and causing a crossfire.
There are two different coil heights, so if your cap and rotor come with a new set of scre
As we said before, the gap at the rotor tip to the cap increases with age and the rotor will crack after enough heat cycles. Note the carbon tracking and corrosion on the right rotor that reduces performance.
As we said before, the gap at the rotor tip to the cap increases with age and the rotor wi
After we replaced the cap and rotor, we disconnected the four-wire connector to the distributor to set the timing. It's just like disconnecting the vacuum advance on a noncomputer-controlled distributor, so you are seeing the initial setting only.
After we replaced the cap and rotor, we disconnected the four-wire connector to the distri

It's hard enough to see the timing tab without all the crud caked on it. We used some Justice Bros. cleaner to spray away the oil so we could see the marks.
It's hard enough to see the timing tab without all the crud caked on it. We used some Just
With the four-wire disconnected, we set the timing to 6 degrees BTDC, in accordance with the emissions sticker on the radiator support. As we add some performance, we will likely add a few degrees to the initial to see what it does.
With the four-wire disconnected, we set the timing to 6 degrees BTDC, in accordance with t
After we set the timing, we noticed the idle was pretty rough. A quick dusting with WD-40 revealed some vacuum leaks. OK, a lot of vacuum leaks. We found at least six broken hoses and emissions-control connectors that were leaking. WD-40 is flammable, so when you spray it on a leak, the engine rpm goes up. A safer method is to use water that is not flammable and will slow the engine down, but what fun is that?
After we set the timing, we noticed the idle was pretty rough. A quick dusting with WD-40

Another basic is to check to see if the choke has 12 volts and opens all the way. A closed choke on a warm engine is a great way to waste gas and have a rough running engine.
Another basic is to check to see if the choke has 12 volts and opens all the way. A closed
After we finished setting the timing and fixing the leaks, we grounded the A and B terminal on the assembly line data link (ALDL) and watched the engine light for codes. The light will flash code 12 (flash, pause, flash, flash) three times at the beginning and end of the code string. Six code 12s in a row means no warning codes are in the computer. Disconnecting the four-wire to set the timing might make code 42 appear. Disconnecting the battery clears the codes.
After we finished setting the timing and fixing the leaks, we grounded the A and B termina
This nasty thing is the breather that allows fresh air to enter the crankcase as part of the positive crankcase ventilation system (PCV). This one looked original, so we replaced it.
This nasty thing is the breather that allows fresh air to enter the crankcase as part of t