Thread: backfiring, stumbling and misfiring... please help!

Tweet

Ok,

I think I know the answer to my problem but here goes...

I have a 1963 427 T-Bird with a 427 center oiler C5AE-A heads. I've owned the car almost 2 years and have driven it maybe 100 miles in that time. When I bought the car it had a really cheap rebuilt Holley 750 on it which I replaced with a really trick Holley 750 punched out to 932 cfm by one of the east coast's best builder's. The 1960's Mallory dual point ignitiion was scrapped for a MDS 6A and a matching pro-billet distributor.

The package ran and performed flawlessly every time I ran it until today. I took it out of storage where it has been for a year and it ran great. , I drove it about 3 miles to my home for a wash and a little tlc. I hosed off the innner fenders and took care not to get the engine wet. The 6A box got a little wet and I wiped it down when I dried the inner fenders.

When I started the car to put it back in storage it didn't want to start. It backfired, sort of started and died. I killed the battery trying to restart it. This had never happened in the last 2 years of monthly starting and running but little or no driving with the exception of a few trips around town and 2 trips to the gas station.

My first impression was I got moisture in the distributor cap. I removed the cap and cleaned it well with WD-40 and reinstalled it. The symptoms persisted. I drove the car and it felt like it was running on 4 cylinders. I checked the carburator squirters and they were fine. The fuel filter was full and everything looked as it should.

I thought perhaps I'd simply fouled the plugs in trying to restart it so I removed the plugs starting on the right side. All 4 plugs on the right side (#1-4) were dry but covered with balck soot (carbon fouling). The left side (#5-8) were clean and perfect.

I got it in my head I had damaged the 6A box getting it wet so I replaced it. It was a second hand unit I had gotten from a buddy and it seemed like the most likely cause. It wasn't. $198. later the symptoms were exactly the same. I verified spark with an induction timing light on all 8 cylinders. All seemed normal and all cylinders showed spark.

Like I said I think I know the answer. I've been out of the hobby for awhile and I'm questioning what I thought I knew as evidenced by my $200 mistake earlier today. Anyone have an idea???

You didn't say anything about the fuel....How old is it? When you stored the car did you use any StaBil or anything? Today's fuel is junk and doesn't take to extended storage well. Fouled and sooty plugs along with old and stale fuel would be a good way to start.

I'm thinking so too Dave.

The days of vehicles setting for long periods of time without any gas treatment, and then firing up and run good are gone. I'm with Dave.

Like Dave said, we're too far apart to actually be hands on to hear and feel it. Change the plugs to insure firing. Double check heat ranges. I'm assuming non-roller cam so the distributor gear has chewed itself up and came out of phase. Stay with the little things like plugged metering block on primary side of carb. Clean plugs at right heat range, etc. You said you used a timing light to check all eight, were all eight flashing at their correct timng marks? Just a thought.

Nothing exotic like a roller cam... (shows how old I am). It ran fine before I shut it off to wash it. I think I had some crud build up in the carb and running it caused it to break loose. I'm going the lazy way first and running 2 quarts of Seam Foam throught the system and if that doesn't work I'll clean the metering block manually.