The AntiRice

Just rebuilt the 12a, now its having a wierd fuel issue that I can't quite figure out.

After I got it rebuilt, I drove it around for about 300 miles with 0 issues what so ever. Then all of the sudden, I'd be driving down the road cruising in 5th, then it would start stuttering, lose power, and die. Most obvious thing to me was the fuel filter since the car sat a while before I restored it, figured that maybe there was some crap in the gas tank or something. So I replaced the fuel filter, worked great for the next 100 miles or so, then started doing it again. Bought another fuel filter, worked great for about 20 miles, then started doing it again...

But here's where I'm confused...

I'll be driving it down the highway or whatever, then it starts stuttering, so I turn the car off. I wait literally 3 seconds, turn it back on, then it will work fine for another 5 miles or so before it does the same thing. So here I am driving 70mph down the highway, I feel it start stuttering, turn it off WHILE I'M DRIVING for about 3 seconds, turn it back on (keep in mind I'm still going 70mph, but just losing some momentum), turn it back on, then can drive completely fine for another 5-10 miles before it does it again. So considering my drive to work is about 20 miles, I'll have turn it off, then right back on 3,4, sometimes 5 times WHILE DRIVING.

So maybe something electrical? Bad fuel pump?

I don't think its the spark plugs, the car is running rich, but it always starts right back up whenever I turn it off, and drives good, but I could be wrong. I really think its something between the fuel pump and fuel filter, but at this point, I'm lost.

What would you guys check?

Almost forgot to mention, it supposedly had a new fuel tank, carter 90gph electric fuel pump, 4.5 PSI regulator, carburetor, plugs, plug wires, coils, cap/rotor when I bought it, then I rebuilt the motor and removed all emissions/rats nest

PercentSevenC

Carb icing, perhaps?

Jeezus

iTrader: (4)

Turn the regulator down to 2-2.5PSI.

Kentetsu

It sounds like the fuel system is "almost" keeping up with your demands. Maybe you've got some crap in the tank which is fouling your filters?


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pyromaniac9912

same thing just happened to me almost identical problem. I just took my gas tank in and had it acid washed and recoated in zinc. problem fixed.

gsl-se addict

iTrader: (3)

Usually it is crap in the tank that causes this. It builds up on the inlet screen and chokes off the flow. You turn the pump off, the crap falls off the screen, and it works okay for awhile.

Might also be a partial blockage in the return/feed hardlines.

Jeff20B

iTrader: (13)

Or the tank vent isn't venting anymore. A vacuum develops in your tank and shutting off the fuel pump (by way of the ignition switch) allows air in.

trochoid

iTrader: (6)

Drain the tank through a paint filter and see what's left in the filter. If there's crud in the filter, you may need to drop the tank, remove the line set and rod out the supply tube. If that's the case, have the tank boiled and sealed.

Retro Racer

Had a very similar problem, some crud lodged in a new fuel filter which some ******** (me) had fitted back to front late one night... End result was the crud would be sucked to the inlet side of the filter, block it off, car would starve for fuel...

Fitted a new filter the right way then the problem happened less frequently... Same ******** (me) had kinked the fuel line when refitting the fuel pump guard on another late night.

Never had a problem since, but I do change fuel filters regularly as the second hand tank I fitted was quite bad at first and was clogging filters pretty quickly first the first 6 months.

I agree though, make sure the fuel pressure is 4psi maximum otherwise the fuel pressure will over ride the needle and seats causing flooding and a smoking/lumpy idle.

DivinDriver

iTrader: (15)

Definitely a starvation problem; sounds like you're running off what little can get into the bowls each time the feed is restored, by shutting off.

What year is your car? If it's an SA, it could have to do with the tank vent valve or the controls for it.

More likely, it's crud-lock as others have mentioned.

DivinDriver

iTrader: (15)

By the way, where can I find a place to boil and seal a tank? Radiator shop, or what type of shop?

I'm not having problems far as I know yet, but it is getting old, and has sat for a while.

Rogue_Wulff

I have run into a similar problem. The car had spent a lot of time sitting, several times thru it's life. (79 model car, had under 95K on it).
The problem was actually multi-fold. The tank had a bunch of crud in it, as did the lines. This not only plugged up filters frequently, but since someone had moved the filter to the outlet side of the pump, the pump also became clogged with crud.
After cleaning out the lines, and getting the pump cleared of crud, it still starved for fuel at anything above 2K. Turned out that there was a layer of varnish inside the tank, and it had settled into the depression under the pickup tube, nearly blocking it off completely. I used an acid based A/C coil cleaner inside the tank, which removed that layer of sludge, and the problem was solved, right up until he blew the engine..........