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Tip(s) for solving a fuel problem

T

TrippinBilly

New Member
1966 289 V8
Autolite 2100
Fuel pump: Holley mechanical pump 110 GPH

After bringing my car up to operating temp and starting to drive it, I flood the engine within 10m. Initially thought it was vapor lock, but ruled it out. I found that if I take an incline and ride the accelerator, I can flood it out pretty quickly. After about 30m or so, the engine will start again and idle fine.

I've replaced the stock fuel pump (well, a repro) with the one noted above and replaced the power valve, but still can't solve the flooding problem. The carb has been recently rebuilt, probably about 4 months ago.

Any suggestions of where else I should look?

Thanks in advance.
 
I would say it has to be a carb issue. The fuel pump will not over ride a properly operating float and needle valve. Even being rebuilt, it can have issues like warped lid, pinched gasket, or not properly adjusted. I have seen many new ones not function properly.
 
First thing I think of when I hear 'flooding the carb' is a float that's adjusted too high, especially if it's worse on an incline/decline. Try reading the instructions to adjust the float.
Jon
 
Thank you for the feedback...

In asking around, someone else asked me: rather than it being flooded, could it be possible that the carb is running too lean? I hadn't thought of that, which still potentially points to the float. So, yesterday I took her out to troubleshoot, went up a steep hill in the neighborhood and hit the accelerator hard. The engine stalled out. It didn't recover in 30m, so we pushed it home. After sitting in the garage for an hour, I still couldn't start it. I poured a little gas in the carb, and the engine started to turnover, but wouldn't stay on. Later in the day, I cranked it, and the engine started.

I haven't had a chance to check the float, but will today.
 
Does it smell like fuel under the hood? Does it burn your eyes? Try removing the air filter and get the engine running. Does the fuel spit out the breather tube? If so it might be your needle and seat out of adjustment. Now, I don't know if there is adjustment for an autolite but it's similar to a Holley. I know on a Holley, if you tighten a needle and seat all the way down to baseline and then back it off until the site level pokes to the site hole then...it is possible when tightening the needle and seat that it was tightened so much that it bends the float tab down. If the tab is bent too much then when the fuel level rises the float rises but the bent tab doesn't come up high enough for the needle to seat all the way. This allows fuel to pass through even after the float hits the top and fuel pushed out the breather tube and dumps into the intake.
I had this problem a few years ago after installing a monster electric fuel pump. I thought it was pushing past the needle and seat so I swapped in different regulators, even different pumps thinking that was the problem. I the end I swapped the carb out and eventually someone told me to try that float tab fix. I've been running that carb for years since I fixed the bent tab.
 
It doesn't smell like fuel. Matter of fact, if I pour a little gas in the carb, it starts to turn over. I adjusted the float because it was way low. I adjusted it to spec, but have not had a chance to drive it. Don't want to get stuck right now. I think it was running way too lean. Car idles fine. Engine stalls out after about 10m of driving or heavy acceleration.
 
Check the condition of your gas cap. Should be a vented cap design. If you put a later model non-vented cap on, you would create a vaccum in the tank and no fuel output from the pump after driving for awhile.
 
Ok, another piece of info.

So, I did adjust the float in the carb to spec. I brought her up to operating temp. She idles fine @ 700rpms. If I put her in drive, keep my foot on the brake and hit the accelerator (and immediately release it), the engine dies. It will start back up since I'm not driving it around.
 
I don't know if this helps any or not. I had a Summit fuel pump on mine which was actully a reboxed Holley. It produced too high of pressure and the Edelbrock carb didn't like it one bit.
 
"tx65coupe" said:
I don't know if this helps any or not. I had a Summit fuel pump on mine which was actully a reboxed Holley. It produced too high of pressure and the Edelbrock carb didn't like it one bit.
Click to expand...
What did you do to solve: new fuel pump, regulator?
 
I ended up switching to the Edelbrock fuel pump that is recommded for the carb. Its been fine for 2-3 years now.
 
The very first thing you should do when you have a fuel problem is change the fuel filter(s). There may be a small metallic one at the carb and maybe another one in line so don't miss one. Also look for a crimped or pinched fuel line while your under the car. Do this and report back.
 
I didn't see any kinks in the fuel line. I'll be ordering a new filter. Need to find a fuel inlet that will fit the Autolite 2100 as I want to change to a glass body fuel filter versus the standard one that connects to the carb directly.

Today was the first day I was able to drive since I adjusted the float to spec. I brought the car up to operating temp before taking her out. Drove around the neighborhood (<25mph) with no issues. Then got out on the main road to another neighborhood and she eventually died. She wouldn't start back up. Cranked it 3 or 4 times over a span of 20m with no luck. So, I popped the top of the carb off and lo and behold, the fuel bowl was empty. The needle and float moved freely. So, I cranked the engine a few times, with the top off, until I saw the fuel squirt up. I put the top of the carb back on, and she started fine and I was able to get her back in the garage.

So, I'll replace the fuel filter, like Jonk67 suggested, but I am curious if this is a symptom of something else.

Thanks again for all of the help.
 
Two problems come to mind:
(1) a clogged fuel line within the tank; perhaps the filter sock is clogged.
(2) The fuel pump works off of an eccentric on the crank, but a longer bolt in the water pump can interfere with the pump lever just enough to allow fuel in low demand situations, but the car will die whenever a moderate fuel demand is required. Did you change the water pump lately? This scenario assumes using the standard Ford fuel pump; I re-read your original post, and it appears you are using an aftermarket pump.
 
&quot;Midlife&quot; said:
Two problems come to mind:
(1) a clogged fuel line within the tank; perhaps the filter sock is clogged.
(2) The fuel pump works off of an eccentric on the crank, but a longer bolt in the water pump can interfere with the pump lever just enough to allow fuel in low demand situations, but the car will die whenever a moderate fuel demand is required. Did you change the water pump lately? This scenario assumes using the standard Ford fuel pump; I re-read your original post, and it appears you are using an aftermarket pump.
Click to expand...
  1. I'll check that one.
  2. No, I didn't change the water pump. The fuel pump is a Holley fuel pump but I had this same problem with a repro fuel pump.
 
I like to put the fuel filter right before the mechanical fuel pump where the rubber line resides between the hard line and fuel pump.
 
&quot;cmayna&quot; said:
I like to put the fuel filter right before the mechanical fuel pump where the rubber line resides between the hard line and fuel pump.
Click to expand...
I just saw your YouTube video on installing a fuel sending unit. Where did you get that lock ring wrench?
 
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