VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc In serious need

I’m at a loss. I changed the oil on the 35 1.5 ton - original engine (one rebuild about 50 years ago). My oil pump has been suspect for about 30 years. It doesn’t like to prime after a change but holds good pressure otherwise. I have a tool made up to put on the drill to run the oil pump after a change so I don’t have to run it without pressure. I pulled the distributor and got it to prime. I put the distributor back in and it fired right up but ran rough. I drove it just a couple miles to make sure I wasn’t imagining things and figured I had the dist. a tooth off (I wondered at the time if I wasn’t one off). I moved it a tooth. No improvement. I’ve gone a tooth in both directions to no avail.

I’ve put on new plug wires, plugs, timed it with a light - all of the things. It still isn’t running on cylinders 4 and 5. I pulled the intake and exhaust to make sure there wasn’t a blockage on exhaust. I pulled the valve cover with it running to make sure it hadn’t had a weird valve train situation.

Nothing

I drove it in, changed the oil, and now it’s down. What am I missing?

wouuld try switching the spark plug wires with each other on those two cylinders and making sure the others are going to the correct cylinders. Also check rotor.

Yup, done. I’ve verified that firing order a million times. I’ve pulled wires and checked the temperature of spark plugs hatter it has been running.

If I go out right now it will fire right up, but misses on those two and has no power. I replaced the timing gear about 2000 miles ago so it isn’t that, although I would have caught some timing issue when I strobed it.

The thing is, I never touched the cap or plugs when I primed it. There must be something coincidental but I am missing it. All of the engines I have rebuilt and fixed in my years farming - this one has be stumped. I’ve tried everything I know to do. I’m going to compression test it today to see if there is anything weird going on. One of these days that 88 year old engine will throw in the towel with as much as I use the truck.

I had something similar recently on my '36. I have several cars and the last time this one was really run was on the early six tour to the redwoods. I do not remember the tour mileage but probably something in the 250 + range. Ran great, after that it was put into storage and not run for a couple of years. Went to get it going and it ran like crap. Sputtering, missing, no power. Suspected the carb due to sitting so spent the afternoon disassembling and cleaning. Got it all back together, same problem. ????? Got my tune up equipment out and started with the dwell. Off the dial. Pulled the cap and the gap did not look all that wide but checked it. It was so wide that the coil could not load up to fire. It had all the symptoms of a dirty carb, and I would have bet $20 that was it but no. No idea as to how it got that far off.

The point is, make a list of potential possibilities. Start somewhere, top, middle, bottom, and one by one check them off. It could be one problem, it could be a combination of three like the overheating problem on my '29 coupe. You just wont know until you check them out.

Please let the forum know what you find because I can guarantee someone else will end up with the same, or similar problem.

Art

bad distributor cap sometime they can crack and you can't see it. sounds like low compression, head gasket?
Jay D.