Help! 1965 F100 dies/bogs/hesitates after 50mph

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Toyz
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Re: Help! 1965 F100 dies/bogs/hesitates after 50mph

Post by Toyz »

RRTEC wrote:That makes a lot of sense. I have been having issues with timing. I followed the procedure to a T about 20 times since buying this truck and have never been able to get it right. It seems happier at further advanced. I have it set at 12deg advanced right now with the vac. Advance hooked up although it is much happier at 18-22deg... No detonation/spark knock although that seemed crazy.

One other factor I forgot to mention is that per some advice I received I had converted to a pcv valve instead of a vented cap. I have noticed that this seems to have upset the system somehow. I unplugged it yesterday and the truck idled better with that open vac leak where the pcv was. In plan to block that off too and put a filter back.

One last thing I noticed before removing the pcv hose is under heavy acceleration I hear a hissing/sucking sound. I have done a vacuum leak check via propane and a vacuum gauge and didn't have leaks.

If you are running better with no PCV in place and an open vacuum leak, it is not likely lean, at least at idle. iI fact it sounds as if it is too rich at idle. What are your vacuum gauge readings? It also sounds as if you have the vacuum advance plumbed into a full manifold vacuum source instead of the needed ported source. An internal vacuum leak at the manifold to head is not unheard of on a rebuilt engine. It is possible also that cam timing is also off, although that is unlikely to cause dieing at higher speeds.
Paul
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RRTEC
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Re: Help! 1965 F100 dies/bogs/hesitates after 50mph

Post by RRTEC »

The advance was plugged into a ported source. Vac gauge reads 15.

The pcv made no difference to performance. It definetly runs itself out of fuel

I am 90% sure I have a fuel supply problem
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Re: Help! 1965 F100 dies/bogs/hesitates after 50mph

Post by RRTEC »

Replaced the fuel pump yesterday. No help.

I am going to bypass the steel lines tomorrow.
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Re: Help! 1965 F100 dies/bogs/hesitates after 50mph

Post by RRTEC »

I went back to my old ways of just buying crap. I installed an electric fuel pump and actually made the situation worse. So through that I learned that the fuel tank pickup tube is clogged. I hooked up the pump and put a bucket under the front filter it was only pumping a trickle. So I bypassed the tank all together and used a gas can to feed it. Whoosh... Fuel came pumping. I removed the hard line to the tank and tried to blow through a section of hose into the pickup. It was clogged wouldn't pass air, so I hooked up the compressor to it and blasted it free.. But there is something in the tank apparently. I pulled the sender a few months ago and there was no sock on the end of the pickup so this will happen again..

What do I need to do now?
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Toyz
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Re: Help! 1965 F100 dies/bogs/hesitates after 50mph

Post by Toyz »

Pull it, clean it, re-install.
Paul
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Re: Help! 1965 F100 dies/bogs/hesitates after 50mph

Post by RRTEC »

The problem is the pickup tube has no filter so this could happen again....
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Re: Help! 1965 F100 dies/bogs/hesitates after 50mph

Post by Toyz »

If you get the tank clean; there should be no recurrence. One could long ago buy replacement "socks", but I see no reason to do so. Plugging the "sock" means pulling the pickup assembly, I'd prefer letting the external filter warn me of potential of comtaminents.
Paul
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Re: Help! 1965 F100 dies/bogs/hesitates after 50mph

Post by bruceandersson »

Wow, long process, but it sounds like you are getting close to the end. Do not try to use any of the gas tank cleaning/sealing kits. They are a waste of money. Either have it done by a shop that can really get all the rust out or use Muriactic acid to do it yourself. Once the tank is clean, you can use a sealer on it with good results. You can get Muriatic acid at a good hardware. Be careful this stuff is strong. fill the tank mostly full with water and add a gallon of muriatic acid, then fill completely with water. Wear eye protection and gloves. Once it sits over night, you will have taken all the rust out. I just poured the acids mixture on my limestone driveway to neutralize it. Don't know your situation. You could also just rise it with a lot of water dilute the acid. There are better instructions on the web. My tank came out looking brand new. Ran for 8 years and no issues.
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Re: Help! 1965 F100 dies/bogs/hesitates after 50mph

Post by RRTEC »

Well I have decided to replace the tank with a mustang tank under the bed. I temporarily fixed my fuel starvation by removing my malfunctioning fuel sender adding some brass fittings and a length of hose as well as a sock filter into the tank. Truck back to running good.

Next on the list- figure out why my truck gets hot while sitting in traffic...
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