Missing something obvious..

[technos]

Replaced the distributor in my 1971 Opel yesterday. (Thanks, Jim!)

But my eyes are tired, my brain stopped functioning, and the damned thing still isn't running right. I'd like to run it past y'all, for some fresh ideas.

Before the swap, the car ran well enough. But the distributor had a centrifugal advance mechanism largely consisting of shredded, bent metal, making the idle timing completely random, the odd backfire on throttle down, and making fuel economy horrible.

After the swap, the car ran horribly. New points at 016, the last brand new condenser I could get locally, new cap and rotor, new wires, new stock plugs at 030, engine timed properly. Backfires, misses, no power at all. I removed the distributor close to the #1 firing position, and on reinstall I made sure the timing marks were lined up.

Gradually I swapped each part out, save plugs, which looked and tested fine, for the originals. Same result.

So I think to myself that perhaps I've got two bum condensers on my hands. They're the only part I couldn't say for sure were okay, and I can't get another without a wait, so I moved up a planned upgrade. Went to the local VW tuner and plunked down a chunk of change for a Pertronix 1847V.

Pertronix is installed properly with the 030 gap between wheel and sensor. I did not use the aluminum spacer included with the kit, without it looked closer to proper height than with it, and can't remember if I used it last time or not.

The car never started so easily! But still misfiring, backfiring.

"Maybe I'm not getting enough voltage at the Pertronix.." I think. So new run of copper from the fuse box to replace the clear resistor wire, new Bosch internally resistive coil. I could swear that on my last Opel (And indeed, the forums back up my memory) that the resistor wire was third from the right, and that there were two unused spades. On this one, it's third from the left, and there is but a single spade. Checked to make sure it was indeed switched power, and that it's the only 'clear' wire in there. More PO weirdness, I think.

No improvement.

Checked for vacuum leaks with carb cleaner. Removed and plugged the line to the brake booster, in case it decided to start leaking vacuum. Re-checked the cans on the distributor, they're fine. Did a new initial tune of the Weber.

Ideas? Please? I'm out of them. I'm ready to take a hammer to something, like my own skull.

[baz]

how are the valve gaps ? if the inlets are too tight you will have a nice quiet motor without any ticking but it will backfire like crazy

did you fall for the oldest trick in the book and believe the haynes and other works manuals and set it up there way which gets the timing out 180 deg for 1 and 4 , which also gives tons of backfires

[technos]

If it were the valves it should have exhibited the condition before the swap too.

I'm not sure if I fell for the "Haynes 180 trick"..

I'm comfortable enough with pulling a distributor I didn't exactly consult a manual when doing the job, except to correct the brain fart of not remembering the firing order between distributor cap swaps. (1-3-4-2, clockwise rotation, #1 at lower right with vacuum cans parallel to the engine, just to show I got that right!)

Assuming I did fall for it, or that I moved the motor without remembering it, how would you suggest checking?

[Anonymous D]

See part 2 of the article from June 2006,
on the page below:

Engine

[technos]

Didn't fall for the 180 trick. Good, because I hate fitting my arm in to pull the fuel pump.

Just had the valve cover off and the spark plugs out, and with the camshaft pin at 6:00 and the timing mark aligned the engine is indeed firing #1.

But.. I think I found the problem in the process. #1 and #4 plugs were totally fouled. And the other two were totally clean.

I swear I checked them for fouling at several points. Okay, maybe not since the Pertronix, but..

Time to clean them, reassemble, and try again.

Jim

[technos]

Thanks, folks. Opel running again, and better than ever. The fouled plugs found checking the cam position led me straight back to the bad part causing things.

Turns out of the new plug wires I installed were not crimped right. Sitting on a valve cover with a long screwdriver in them to check yielded spark. Bent and routed to a plug, no spark.

Replaced them with another set and everything is as right as rain.

Well.. I need to fix the now leaking valve cover gasket with sealant, but.