Chevy 454 Distributor Remove/Replace

[DaveVA78Chieftain]

DISTRIBUTOR REPLACEMENT
Some components, such as the engine cover or air cleaner, may need to be removed to reach the distributor.

DISTRIBUTOR WITH INTEGRAL COIL

Remove or Disconnect
1. Engine control switch battery feed wire from the distributor cap.
2. Tachometer lead (if equipped) from the cap.
3. Ignition coil connector from the cap.
   Note: Do not use a screwdriver or tool to release the locking tabs.
4. Distributor cap by pressing down on the four springloaded screws and turning the latches to the left.
5. Vacuum hose from the vacuum advance unit (if equipped).
6. Distributor clamp bolt and hold-down clamp from the engine.
   Note the position of the rotor, then pull the distributor up until the rotor just stops turning to the left. Again note the position of the rotor. B Install or Connect

Install or Connect
To ensure correct timing of the distributor it must be installed with the rotor correctly positioned. Refer to step 6
of the removal procedure.
If the engine was accidentally cranked after the distributor was removed, the following procedure can be used for installation:
  A. Remove the number 1 spark plug.
  B. Place finger over the number 1 spark plug hole and crank the engine slowly until compression is felt.
  C. Align the timing mark on the pulley to "0" on the engine timing pointer.
  C. Turn the rotor to point between number 1 and number 8 spark plug towers on the distributor cap on V8 engines and between number 1 and number 6 on 6 cylinder engines.

1. Distributor.
  Note: If the distributor shaft won’t drop into the engine, first insert a screwdriver into the hole for the distributor and turn the oil pump drive shaft.
2. Distributor hold-down clamp and clamp bolt.
3. Vacuum hose to the vacuum unit (if equipped).
4. Cap on the distributor.
   Note: The aligning tab on the cap should engage with the notch in the housing.
5. Four hold-down spring latches.
6. Ignition coil connector to the cap.
7. Engine control switch battery feed wire.
8. Tachometer lead (if equipped).
   Note: Set ignition timing. Refer to "Ignition Timing" in this section.

IGNITION TIMING  (Not unusual for timing tab to be on bottom side of damper)
1. Refer to the Vehicle Emissions Control Information label located on the radiator support. Follow all instructions on the label.
2. Refer to the Fuel and Emissions Service Manual for timing information for engines equipped with TBI.
3. With the engine control switch off, connect the pickup lead of a timing light to the number 1 spark plug. On engines with the timing pointer mounted at the oil pan, use the number 8 (or number 5) spark plug. Connect a jumper lead between the wire and plug or use an inductive type pick-up. DO NOT pierce the wire or attempt to insert a wire between the boot and the wire. Connect the timing light power leads according to the manufacturer’s instructions.
4. Disconnect the vacuum hose from the distributor if so equipped.
5. Start the engine and aim the timing light at the timing mark (figures 11 and 12). The line on the balancer or pulley will line up at the timing mark. If a change is necessary, loosen the distributor hold-down clamp bolt at the base of the distributor. While observing the mark with the timing light, slowly rotate the distributor until the line indicates the correct timing. Tighten the hold-down bolt, and re-check the timing.
6. Turn off the engine and remove the timing light. Reconnect the test spark plug wire, if removed.
7. Connect the vacuum hose to the distributor (if equipped).

Dave

[ClydesdaleKevin]

Great and clear instructions, Dave!  Thanks!

Kev

[DaveVA78Chieftain]

Copy paste from the Service manual.

[BrandonMc]

This may be obvious but I still need to ask,


To install a distributor do you use the TDC of #5 cylinder using the bottom timing mark on the harmonic balancer rather than using #1 for TDC plug per the instructions?

The instructions say to use the alternate position #5 when timing the engine. But for simply installing the distributor I am not clear if you would still need to use #1 to find TDC? because simply, I am not able to see the upper side mark, and I'm also assuming the bottom mark isn't going to be good to line up 0 for the #1 cylinder.

Likewise, if my assumption is correct to use TDC at #5, the rotor would then need to be placed between the number 5 and 7 position when installed.

[tmsnyder]

If you use the #5 pointer, that means #5 is going to be at TDC.   The distributor rotor will be pointing at the #5 spark plug wire on the cap.  So it's the same instructions as if you were using #1, just use #5 instead.


That assumes you are on the compression stroke and not 180 degrees off under the distributor cap.  I use a long regular screwdriver to turn the oil pump a little so as the distributor rotates as it drops down in, it engages the oil pump and turns it that last little bit.   Otherwise you end up with the distributor not seating down in fully into the block, it sits on top of the oil pump.  Just don't drop the screwdriver down into the block LOL  Use a bit enough one that it won't fit down in there!

[BrandonMc]

Thanks for the replies! I thought Dave had replied earlier too.


Well, I had to ask because I was troubleshooting a brand new distributor, and turns out - out of the box brand new DST1845 wasn't sending the spark at the posts. Ended up ordering another distributor, and sent the old one back. This new one worked like a charm.


Also, I found this video helpful for a diagnosis after testing the coil among other things per the flowcharrt in the service manual: https://www.youtube.com/watch?v=763z6IGyExI

[TerryH]

Are you quite sure that the video you linked to is the one you wished to post?

https://www.youtube.com/watch?v=763z6IGyExI

[Rickf1985]

Running a distributor with no loads on the terminal is NOT a good idea!