Gassed

I’ve got a few miles under my belt with the new rear spring bushings and a new fuel pump. The springs ride fine, but I’ve only noticed minor improvements to ride quality. I’ve still got a bit of noise in the rear, too, so I will likely be looking to replace the springs at some point in the future.

I haven’t been paying much attention to the ride, though, as I’ve still got some—potentially serious—issues under the hood.

The new fuel pump didn’t resolve the fuel pressure issue. Suspecting a clog in the filter at the pickup in the tank, I crawled underneath and pulled the sender from the tank. The filter, which I’m pretty sure was there when I installed the unit, was no longer attached. So, it fell off at some point or it got knocked off when the sender came out of the tank. In either case, the only result from this evolution is that the sender no longer works. Ug.

After running a few minutes with the new pump, fuel pressure dropped down to near zero at idle.
After running a few minutes with the new pump, fuel pressure dropped down to near zero at idle.

The only other possible fuel restriction I could think of was the rubber line to the pump. I put a clamp on this line while the pump was off the motor to prevent fuel leaks in my garage. Assuming that the clamp permanently deformed the line, I replaced that too. Whatever the restriction was, it’s now gone and fuel pressure is nominal.

The fuel filter inside the cannister of the old pump was clean--just a little residue at the bottom.
The fuel filter inside the cannister of the old pump was clean–just a little residue at the bottom.

With that fixed, I no longer have the hiccups and stuttering. Unfortunately, I’ve still got an engine miss at speed, and it’s getting worse. The problem might be ignition related, but it appears to be a associated a valve train tick that’s getting ominously louder.

I’ll check the timing, but I’ve long said that this would be the year to freshen the engine. Now may be the time to pull it.

6 thoughts on “Gassed”

  1. Being a 64 bird owner/driver/maintainer I’ve enjoyed seeing your blog the past years (has it been that long?). I pulled my engine a couple years ago even though it ran perfectly fine. Mainly because if there was a gasket, it seemed like it leaked oil more than it held it in. With only 80k+ miles on it, I took the block to one of my engine building buddies just to inspect the cylinders. A light honing was all that seemed necessary so the block was put in the oven and baked to the point it looked like fresh iron again. I even reused the original pistons after a thorough cleaning of everything to the point it all looked new again. New rings, bearings, a very mild performance/economy cam, and the much fresher set of heads from a previous 64 390 build topped it off. Very little cash outflow and the end result is an even better running engine that doesn’t leak or smoke or stink out the exhaust in the least bit.

    1. Glad you’ve enjoyed the blog. I’m hoping for the same from this motor. It’s got some 35,000 miles since the previous owner rebuilt it. It was bored .030 over at the time, so it would be nice to inspect and reinstall a lot of the same parts. Instead, it would be nice to put money into a roller cam and balancing.

      When you pulled the motor, did you do the engine and transmission together?

      1. No I left the trans in the car the whole time. Just put a new input shaft seal in the front part while I had access to it. At some point I wouldn’t mind rebuilding the power steering control valve and slave cylinder. I’ve rebuilt both of those a couple times on a few other cars with rebuild kits. My trans still has a few small leaks here and there too, mainly where the shift lever comes out the side.

  2. When you say freshen. Do you mean rebuild? Let me know as I would like to consider a top end rebuild as well for my 64. I was hoping to find someone down here in so cal. Thanks.

    1. I’m hoping it won’t need a full rebuild, but I’d like to bring it up to spec, stop the oil leaks and move up to a roller cam. I suspect the previous owner rebuilt the motor on the cheap, so there are probably some improvements to be made. Also, while it’s out, I’ll have good access to the leaky steering box, which I would love to replace.

      Last time I rebuilt a motor, I was in the LA area, but that was decades ago and in the Valley.

    2. Were you asking about the “freshened” heads I mentioned above? If so, yes they’ve been rebuilt with springs and a valve job but that was 25+ yrs ago. They’ve just been on another 390 thats been driven occasionally since then, probably only have 15-20,000 miles on them, if that.

Leave a Reply