1st post - Backfiring question
 

I just bought a '65 F-250 with a swapped 352 FE engine. The PO bought it a few years ago, and didn't really do much to it, repair or even maintenance it seems (he did have the carb replaced two years ago). At low rpms and under load, the engine backfires through the intake badly and has stalled out on me a couple times. I read in the FAQ that I might need to advance the timing to 10 BTDC, and I'll do that as a temporary fix. However, I'd rather not spend the time becoming proficient on a points-style distributor when there are more reliable options out there. I was looking at a plug and play distributor like the one in the link below or similar models by PerTronix, MSD, or FAST. I'd also replace the ignition coil with a high voltage one. Does anyone have experience with one of these distributors? Has it given you better spark? Are there other electronic ignition options I should check out? Thanks.

https://www.summitracing.com/parts/sum-850309-1

https://cimg6.ibsrv.net/gimg/www.for...5d067e665b.jpg
A PO at some point swapped the factory 6 for a 352 V8
https://cimg2.ibsrv.net/gimg/www.for...851b6e0bc3.jpg
Big Blue

Since I want my 69 Mustang 428cj to look original I went with the Pertronix ignition and coil. That was 10 years ago and it has been flawless.

Make sure your distributor is not worn out--bushings wear and the shaft is allowed to wobble around, which will cause the spark timing to wander with it.

Also, if you can, with the cap removed, rotate the engine by hand until the rotor moves. Then reverse the rotation and see how many degrees of slop you have in your timing chain.

As a practical matter two quick things to look at that might save you some time and hassle. With a "new" truck, verify, don't guess or assume that everything is setup according to Hoyle.

Spark plug wires for example, it's not uncommon for those to be installed by a previous owner out of proper firing order. Engine won't run well but it will run, and backfire. Find a junkbox condenser for the distributor or put the old one back in, the new ones sold in the stores aren't any good and will cause misfire/backfire.

Hey, if your up to a short road trip, come up to Tellico Plains and I;ll help ya work thru it. Its free!!

I might take you up on that. I'm originally from Maryville.

There are a number of different distributor options, the question is how much do you want to spend? I also went Petronix with my 390 build and seems to be working just fine - quite simple to wire up to. You could swap in a durafart box and dizzy to get rid of the points- that would be an upgrade in itself. You might even be able to find a conversion module that fits in your existing dizzy, if I recall correctly.

Check to make sure the plug wires are right first, then check the timing and advance to about 8-10* BTDC. Adjusting the timing is a relatively simple task. I believe points are set with feeler gauge. Both tasks are relatively straight forward and low cost, with some reading. Problem with points is that they need to be routinely checked and adjusted. Timing on the other hand shouldn't move once you have set.

If you happen to remove the dizzy, remember, you can be a full revolution out, when reinstalling.

A feeler gauge works good with new points but a dwell meter is the way to go with used points. If the distributor is worn, forget it, it will never hold the dwell. The shiny new condensers sold today are garbage. Put the old one back in.

Welcome anytime...

Thanks for the KISS advice. Some PO had the firing order wrong. Re-order the spark plug wires, and it's purring.

Good deal. That's what troubleshooting these beasts is often about, fixing past errors or mistakes.