dadweiss

I have a 455 olds, 1975, early HEI ignition approx. ie rebuilt, Ran great in our motorhome 1 1/2 years ago.

Problem #1 -
Now, despite new plugs, new dist cap and rotor, 3 new fuel filters, carb and below by an auxillary fuel pump, when I start it, let it warm up and watch the choke open, after about 4 minutes, no matter how fast I have it idling, it begins to shut down. So I could be running about 1500 RPM and after about 4 minutes, is just looses power and shuts down.

I can restart it, but then after about 30 seconds, it still starts to slow down... and dies. All of this while in park. So something seems to me to be warming up, and then something that is warm, makes the engine shut down. By the way, the choke is full open all the time this is happening.

I have tried to find someone local in Vancouver, WA who could help me with it, but so far no one I trust.

#2 - The guy who built this engine, did something with the timing chain, I think to advance it. He always told me, because of running a sea level and then sometimes in the mountain, to advance the timing until I heard it ping and then back it off. At least that is how I remember it. One time, I had a shop try to tune it, and they had a heck of a time. I seem to remember in the dark recesses of my memory, that he told me to tell them to time it to 12 degrees, not the book value. I didn't care much about that because I always tuned it by advancing until I it pinged and then backed it off. (He is since deceased and the records he left are not available. Anyway, I made a mark on the shaft of the Distributor and the block, so I could always bring it back to this when I was at sea level, and know it was right. Now, when I put it there, it is so far retarded, I get no power at all if I try to drive it.

Now when I rotate the distributor clockwise, as I am sitting on the back of the engine, I can't advance it far enough to hear ANY pinging. That doesn't make sense, since I haven't taken the distributor out of the block.

I drained the gas tanks and put all new gas in, and new filters twice.

Another problem is that when the engine gets hot, no matter if I bridge the house and chassis battery, even a brand new starter doesn't have the power to crank it. I have to wait and let it cool.

What kills me is that this ran just fine 1 1/2 years ago.

I also noticed that if I put some liquid on the intake manifold on the passenger side, by the bypass, that I see a little bubbling as if exhaust is leaking at that spot where manifold hooks up to the engine.

So I know this is a lot, but I need some help here to get started getting this engine on the right path.

If you have any suggestions, besides a new motor, you can contact me offline at dadweiss@gmail.com

Thank you so much.

Mark

joe_padavano

This sounds like a fuel delivery problem. Either your pump is going bad or you have sediment in the tank that is being sucked up against the inlet screen on the pickup. The first thing you should do is install a fuel pressure gauge (if only temporarily) between the fuel pump and the carb inlet. Watch what happens when the engine starts to die. If the fuel pressure starts to drop, quit wasting your money on electrical parts and find the source of the blockage. The other possible fuel problem is a crack or other leak in one of the rubber suction side lines. This lets air in (as opposed to fuel out) and will also cause stalling eventually.

jeffrey

It also happens when you put a ping pong ball in a gas tank.......

dadweiss

Thanks for the tips.

I drained the tanks dry. I didn't FLush them, though. But I did put good gas in and I replaced the filters with new ones.

The set up is like this

50 Gal Tanks
See Through Filter
Electric Fuel Pump half way from the tanks to the engine.
12 more feet of fuel line.
The stock fuel pump in the engine. There are two ports there. The normal port is capped off. The fuel line goes into the second port and up the metal riser toward the Carb.
The metal riser is cut, and there is a second see-through filter in the area where the engine temp sensors are.
Then from the filter to the Carb where I have removed the filter normally found inserted into the carb.

When I run the engine, I can see the gas in the filter near to the carb. What should I see if fuel pressure is low? I guess if the filter prior to the electric fuel pump is already clogged, that could be a problem, and I will look at that.

I don't see the fuel disappear from that filter, when it lugs down and quits. Sometimes it slows way way down, and almost dies and then suddenly picks up again and goes back to a normal idle. It might do that three or four times before getting so low in the idle, that it quits.

I tried to explain everything the first time, but I didn't mention the fuel line set up or the filters.

Also, one other problem. Where does the distributor get its electrical power?
Yesterday, it wouldn't even fire. I had fuel in the carb, but like no fire. How do I check that too.

I am sorry to be such a bother here with what must be really elementary questions. I am a bit frustrated. I guess I learned my lesson. I could have fired up the engine every month or so, I might have averted these issues.

Mark

DennisG.

When you get it running take a look at the filter by the carb. Is it full, half full or barely anything in it ? Has the engine been overheated since the rebuild ? Has the coil or the module ever been changed ?

dadweiss

The coil has not been replaced. I am going to check spark today. I don't know of a module? In addition to the coil? It has not been overheated that I can remember. Never low on oil, I had a transmission oil leak when a bolt backed out. But I found that and tightened things up. I notice the the bolts on the valve covers get loose and need to be snugged down from time to time. We have had a broken Exhaust Manifold on the right side for some time. Noisy. I just got one a a new/used one to replace that one.

The chronic problems have been, after warming up, hard to start. Not enough power to even make it turn over even after bridging the house and chassis battery. I think it is too far advanced. But I may be wrong. Has a brand new starter and 3/8" cables going everywhere. Checked cable connections. Cleaned battery connections. Have two new batteries. 12.8 volts on each one.

I am going to get some no-lead battery leads, since I hate the lead based ones.

I think I will try to disconnect the tanks and run a fuel line into a 5 gal can of new gas as part of the test.

I will also pull a plug, turn it over and check for spark. Also check for power to the wire going to the coil.

What else?

Lady72nRob71

Does your starter have the heatshield / bracket in place? It connects from the side of the starter to the block and is about the size of my hand. I have heard a lot about starters and solenoids getting heatsoaked by the exhaust manifold making hot start problems. The shield is missing on my 350 and it has a hot start problem (of course she also had cooling system issues - bad fan clutch, etc.)
Another guy I knew just changed the battery cables and his prob was fixed.
Just some suggestions...