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I wanted to start the engine of my 77 today ( has been sitting for only two days), but it wouldn't start. I checked and there isn't any spark.
Because all the parts of the distributor are very old and worn, I will replace a couple of things...
I read that the following parts get worn out often:
- HEI ignition coil -> SMP dr31 or MSD 5525
- Distributor Condenser -> SMP dr70 or AC Delco 12338665
- distributor cap -> AC Delco d338x or AC Delco d336x
There is an online shop in The Netherlands where I can get parts for old chevy engines... but I can't go there now because the borders are closed for 'tourists' (COVID-19). I had some bad experiences when I asked shop personal for advice, so I'd rather ask it here on the forum..
Which parts will fit my 77 L48 original distributor? The product (-numbers) that are in stock in the shop are listed in the list above.
You don't have a condenser on a '77. Those go with the old style Points & Condenser. ('75 & earlier)
If you purchase a new cap, look for a combo of Cap & Rotor to match. Make sure those are for HEI system.
Your '77 does have a Modular (in place of Points / Condenser) and should be replaced. Look for Heat-Sink-Compound to apply under the Modge also.
Last edited by HeadsU.P.; Apr 8, 2021 at 08:52 PM.
just note Delco has not made ignition parts or other parts in decades. most if not all ignition parts sold for OEM replacements are made by Standard Motor Products
As mentioned, if the ignition system isn't getting 12 volts sent to it, there will be no ignition--even if the ignition system is fine. The Neutral Safety Switch and the ignition switch or 'gatekeepers' that can prevent 12 volts from reaching the ignition system; so make sure those aren't your problem. Also, the starter won't turn if the starter solenoid has failed (or a fusible link in the starter system is kaput). I will assume that you have turned on the headlamps when trying to start the car to verify that the battery has adequate charge??
If power is getting to the ignition system, the most likely fault is the ignition module inside the distributor. There are several other possibilities in that area, but the module is a good bet.
As mentioned, if the ignition system isn't getting 12 volts sent to it, there will be no ignition--even if the ignition system is fine. The Neutral Safety Switch and the ignition switch or 'gatekeepers' that can prevent 12 volts from reaching the ignition system; so make sure those aren't your problem. Also, the starter won't turn if the starter solenoid has failed (or a fusible link in the starter system is kaput). I will assume that you have turned on the headlamps when trying to start the car to verify that the battery has adequate charge??
If power is getting to the ignition system, the most likely fault is the ignition module inside the distributor. There are several other possibilities in that area, but the module is a good bet.
- Checked the 12 V -> OK
- The rotor is turning when I try to start the car. -> OK
- Battery is full (brand new). -> OK
- There aren't any cracks in the cap. -> OK
- Maybe it's the ignition control module, like you guys said? (see pic)What are good modulators that will work?
I buy the USA parts from Amazon or Ebay (because of shipping and import costs to Belgium). They don't have the modulators around here...
Just a nickle size puddle in the middle of the back side of the module. When you tighten it down it will spread out.
As far as the Module Yes the D1906 is the cross for the original GM #1875990 1975-1980 all used the same...
You don't have a condenser on a '77. Those go with the old style Points & Condenser. ('75 & earlier)
If you purchase a new cap, look for a combo of Cap & Rotor to match. Make sure those are for HEI system.
Your '77 does have a Modular (in place of Points / Condenser) and should be replaced. Look for Heat-Sink-Compound to apply under the Modge also.
Before you begin disassembling parts, place a bath towel entirely around the distributor. In the event you drop any hardware it won't fall far.
By removing 3-4 plug wires from the cap on one side the entire unit can then be laid off to the side out of the way.
Smear some Heat Sink Compound under your new module. Pay attention the the old wire harness at the modge and compare to the new unit, matching up perfectly.
I measured the 'pick up coil' or 'distributor pole piece' (don't know what the correct name is). I loosened the connector (red arrow) and measured at the two wires. I read 772 Ohm... Is this good or bad?
77 distributor replacement parts
