308 QV Running rough on one side

Coils & distributors would be your next stop. Suggest you look at swapping parts over from one bank to the other to see if you can trace the fault. Could be something as simple as a cracked/worn distributor cap or a bad/worn rotor arm.

I.

 

Ditto. Is it a twin-distributor setup? There aren't many systems which just affect one bank, and it sounds like ignition breakdown esp if it's a 2-dizzy unit. Check caps, rotor, centre brush, anchoring of leads into cap, advance operation, basic timing, coil feed & grounding, etc.

Also, what did the old plugs look like? If you don't have them, what do the new ones show on the "bad bank". Is there fouling/sooting/oiling on just 1 or 2 or are all the same? How do they compare to plugs from the other bank? This is to try to identify whether the problem is with a full bank (eg distributor, coil, etc problem), or just a couple of cyls on that bank (eg individual leads, plugs, FI restriction, etc).

 

If you replaced one coil wire and one spark plug wire, you're going about it the wrong way.

If you have one bad wire, replace all of the wires, unless they were all replaced recently.

Also check the extenders, they don't last for ever.

If that all looks good, check the digiplexs. 308s are notorious for water getting into the trunk area and corroding the connectors.

Next, get a different mechanic!

 

I agree, it sounds like an ignition problem...a scope should tell you where the problem side it (front or rear bank), but you need to remove the caps, rotors, wires, plugs and extenders for inspection as well. All those items are consumable items that will need periodic replacement, so check and replace as needed. But as mentioned, try and replace in sets. Too many times I see someone replacing a bad extender, then two weeks later another...then two months later another goes and they (finally) replace them all.

Check grounds on the digiplexs. They are in the left side of the trunk, under the carpet....open up the lid and unplug, clean connectors, replug in. Run a tie wrap around the plugs to ensure they cannot be unplugged accidently. Then add an extra ground wire from the corner mounting bolt on each unit (use a heavy 12 ga wire), and connect to a nearby chassis bolt.

Dave

 

Also, I smooze silicone grease all over the connectors, and where the wires go into the connectors.

It keeps the moisture out.

 

That is one HONORABLE repair shop, and worth noting his name, address and phone number!

Please post for all to see.

 

Something I learned many years ago; always replace consumable ignition parts in sets i.e. wires, plugs, extenders etc.

No one is perfect, everyone is entitled to make a few mistakes.

It sounds like you've found a very honest shop. You should post the name and address.

 

That's a good shop