Scratching My Head

[hkestes41]

O.K. here is the situation with my daily driver 48 coupe and what I have done so far.

About 3 months ago I thought I had run out of gas (guage does not work) so I added some gas from the 2 gallon can I carry in the trunk and made it to the station. A couple of weeks later, ran out of gas again only this time I knew I had gas in the tank as I had just filled it the day before. So, I let it sit for about 4-5 minutes fired up and ran several miles then like it ran out of gas again. Same thing let it set a few minutes fire it up and go only the distance traveled got shorter each time. No swoosh when the cap is removed so I think I am getting good venting of the tank.

Changed the carb, dropped/cleaned the tank (a lot of crud in there) blew air back through in tank filter and ran it a few days no problem. Then it started happening again. Changed fuel pumps from spare engine and it ran fine for about 2 1/2 months. Then Friday it starts all over again. Took me about an hour to get back home a total of about 4 miles. Bought a new NAPA fuel pump and it ran fine Saturday until this morning. Made it about 2 miles from home and it started again. Since I was dressed for work and now late for an appointment couldn't crawl under to see if there was fuel in the bowl.

It acts like it is running out of gas. Runs fine then starts sputtering and then dies. Let it set, try to start and the engine cranks over several times then starts runs a little rough then smooths out for a few blocks then happens again. If I keep my speed down it runs longer. Which makes me think that the higher RPM empties the carb bowl faster like the pump is not keeping up then the engine cranking fills the bowl for the next short run period.

Anyone have any ideas? Could it be the coil going bad and as it heats up gets intermittent spark? Sorry for the long winded explanation but I don't know where to look next.

[Normspeed]

Check the little flex hose near the frame rail just in front of the fuel pump. If these get porous, the pump will suck air (much easier to pull air rather than fuel). Also check connections at any inline fuel filters between tank and pump, for the same reason.

[TodFitch]

Check the little flex hose near the frame rail just in front of the fuel pump. If these get porous, the pump will suck air (much easier to pull air rather than fuel). Also check connections at any inline fuel filters between tank and pump, for the same reason.

Worse than that, modern gas can cause the old style rubber to swell and get sticky with the result that nothing can pass through the hose. Last Sunday I was shown a piece of fuel hose from a 62 Valiant that the original owner's son tried to get started after it had been parked for a lot of years (also had problems with bad gas from sitting that long). There was no way that gas or any liquid was going to make it through that hose, even the short 2" section he showed me. I took some photos which I plan to post some time but they are still in the camera.

[randroid]

hkestes41,

You mentioned a lot of crud in the tank. I've seen instances of that crud plugging fuel lines, giving symptoms just like your problem. I'd suggest that perhaps you might blow backwards through the fuel lines (into a can) and see what comes out.

I worked on an old beater truck once with the same problem and found little "strings" of garden hose in the metal line. The tank had been siphoned too many times and when the hose was removed something sharp scraped the side (evidently) and eventually the gas couldn't get through fast enough to feed the carb.

I'd also suggest doing what Normspeed and TodFitch said first, as their ideas are probably closer to the mark.

-Randy

[Normspeed]

Randroid, I agree. I had that happen with a VW bug. The fine rust in the tank found a slightly restricted bend in the steel line and plugged up.

[greg g]

couple things, there is a screen in the pump that will get cruded up. Remove the bolt from the bottom and thecover for the bottom chamber of the pump will come out. You might have to tap it tioget the cover loose, Then scheck the screen. Also check the bolt it self, it is hollow and there might be crude inside it. Then by all means cut the steel line under the doors and splice in an in line filter or two. Use the see through kind so you can check thier condition from time to time.

I replaced the stock rubber line in front of the fuel pump with a piece of steel line. I cut it in half, off set the ends and put in a piece of new neoprene line in a loop to make up for any engine movement.

[hkestes41]

Check the little flex hose near the frame rail just in front of the fuel pump. If these get porous, the pump will suck air (much easier to pull air rather than fuel). Also check connections at any inline fuel filters between tank and pump, for the same reason.

Didn't mention that as one of the things I have done. I have replaced all thr rubber hose from the driver side along the cross member to the pump already

[BobT-47P15]

I did not see any mention of an in-line fuel filter.....which might prove

helpful.

My car did about the same type thing Sunday afternoon.

Died at a stop light like it was out of gas. Would not re-start. Rolled

it out of the street into a parking lot. Cranked it a few more times....

finally started. Kinda missed and sputtered at first....then continued to

run just fine. Went to the nearest convenience store for some new

gas.

This was the first drive after it sitting for the last few

months. I probably should have added some new gas right off as the

level in the tank was fairly low. Will see how it does the next time.

[david lazarus]

I had a similar problem, to confirm if its fuel or not, lift off the airfilter and run the engine at medium revs till it dies....looking for no fuel jetting into the barrel of the carbie when it dies. Then you will KNOW if its fuel or not.

Then....put a cheap clear plastic filter in line before your fuel pump. I ran mine for a while then took this out and cut it open......there I found the crud.

If your line is sucking air, you may even see air bubbles in your clear fuel filter.

The above may not fix your problem but could at least allow you to target a certain area for a fix.

Keep us posted !!

[NatesSedan]

Ditto the clear filter. I have two filter myself. One at the pump and the other before the carb. The one by the carb is a glass (clear) VEry easy to see if your getting enough gas there.

From what you describe my feeling is rust in the tank. I think this because I went through about 3 months of this myself. The last time was a 16 mile trip that took half a day. I pulled the tank and bought a tank sealing kit from Eastwood. I got into the cleaning and didnt bother with the rest. The was enough rust that I decided to replace it. I got the Tanks Inc. stainless tank and have not had any problems since.

Did you take a rubber mallet and tap the sides of the tank when you had it down? Whenever I did this I would get large scales of rust that came out....AFTER the cleaning.

I know your frustration...it is still too fresh in my head.

[hkestes41]

Ditto the clear filter. I have two filter myself. One at the pump and the other before the carb. The one by the carb is a glass (clear) VEry easy to see if your getting enough gas there.

From what you describe my feeling is rust in the tank. I think this because I went through about 3 months of this myself. The last time was a 16 mile trip that took half a day. I pulled the tank and bought a tank sealing kit from Eastwood. I got into the cleaning and didnt bother with the rest. The was enough rust that I decided to replace it. I got the Tanks Inc. stainless tank and have not had any problems since.

Did you take a rubber mallet and tap the sides of the tank when you had it down? Whenever I did this I would get large scales of rust that came out....AFTER the cleaning.

I know your frustration...it is still too fresh in my head.

When I cleaned the tank, I didn't hit it with a mallet, but I did put a piece of chain about 5 feet long from my chain falls inside and then picked up the tank and shook the you know what out of it in all directions for several minutes. Then washed it out with a fairly high pressure hose and let it dry.

Went a picked the car up once I got home this afternoon. Had about a 4 block drive to get it to the driveway and didn't think it was going to make it. Once it cools off a bit I will crawl under and check the pump bowl and take the top off the carb to check the float bowl. Then maybe a trip to Wally World for some filters.

[hkestes41]

Here is an update.

The glass bown on the fuel pump was clean. Even so, I went ahead and installed an inline filter between the pump and the tank.

While I had the line open to install the filter, I once again blew air back through the line to clear the in tank filter. Buttoned everything back up and it has been running fine for the past week.

Since the glass bowl was clean and blowing air through the line seems to have eliminated the problem, I am guessing that I will need to drop the tank and clean it again. Or just get a new tank alltogether.

Anyway, I'm just glad to have it back on the road.

[John Mulders]

Glad you solved it, scratching the head too long may cause damage

John