Carburetor difficulty:

FordGolfer7

New member
Culprit: 1966 Ranchero, 200IL 6, Autolite 1100 Carburetor
Problem: When driving under hard acceleration, the vehicle runs out of fuel. I can take the fuel cap off and there is a major inrush of air. I can then run for a little while before the problem repeats.
Repairs done: Fuel tank removed and cleaned, fuel lines cleaned, filter changed, new vented fuel cap.
Any suggestions on what to do next?
 
Have you checked the fuel pumps pressure and volume yet? It dosnt sounds as though the fuel cap is venting properly though have you verified that they gave you the correct fuel cap for a 66 Ranchero? :nod:
 
Fuel pressure & did you put a new sock filter on the pickup of the sending unit in the tank??
 
Hi, try what was mentioned, and try driving with no gas cap, or the old cap. It sounds like it is not venting. Good luck
 
I have corrected the venting problem, new vented gas cap, tested, new fuel pump, new fuel filter, removed and cleaned the fuel tank, and cleaned the fuel lines.

It is running a little better but still runs out of fuel after driving some distance. Any more suggestions?
I am going to go through the carburetor again in a little while.
 
I'd assume w/a '66 its LOM/SCV.
"... driving under hard acceleration, the vehicle runs out of fuel..."
wonder if that's 1 of those w/a vent tube...cloged? acceleration moves fuel out of bowel? fule pump not strong enuff?

May not B related to:
"... take the fuel cap off and there is a major inrush of air..."?

can U put a fuel gage on it? or measure volume & pressure? C if it's related to (1 or other) g forces or throttle response/position? cable/rod catch on something (not the 1st time)...
 
:unsure: The problem that you describe is fuel delivery related.Have you replaced all the rubber line in the fuel lines?The short pieces between the tank and the steel line,and around the fuel pump?They might be cracked from age or closing up under suction.
Good luck.Have fun.Be safe.
Leo
 
X2 from your description of the problem you need to focus on your fuel delivery system coming from the fuel tank to the carb. Ie the fuel tank and parts, plus the fuel lines. Good luck :nod:
 
An update on the carburetor issue. I have removed the tank and cleaned, replaced the fuel filter, replaced the pickup/sending unit, replaced the fuel pump, cleaned out all fuel lines, installed new gas cap, and replaced the carburetor. I can now start the vehicle and drive it. It would not idle, I started a detailed search for vacuum leaks and discovered that when I pulled the PCV vale and plugged it the engine would idle. My next question is a replacement for the PCV valve. The valve is part number C4UE-6A666-A, will the new plastic valves work or do I need to try and find an exact replacement? I really appreciate all the information provided that helped me get through the fuel issue.
 
That may actually indicate there is a vacuum leak and when you plug the PCV you are making up the difference. The pcv is a vacuum leak of it's own, but it's part of the system and the carb is designed to be in tune with that leak. When you put your finger on the pcv the engine should shudder and want to die. Cheap enough to replace though and test the theory.
 
An update on the Fuel Problem:

I have replaced the fuel pickup/sending unit, cleaned the gas tank and lines, changed the fuel filter, changed the fuel pump, and replaced the carburetor with an after market. I can get the engine running and drive the vehicle, I cannot get it to idle and have hesitation problems. Could this be caused by distributor problems? I have checked to the best of my abilities for vacuum leaks. Could the PCV valve be a possible culprit? ANY DIRECTION OR IDEAS ON WHERE TO GO NEXT WILL BE GREATLY APPRECIATED!!!
 
On a '83 F100 300 six the problem turned out to be the screen in the carb fuel inlet was plugged with really fine rust particles. Once I found this and cleaned it, it was OK. Sometimes we don't realize it's there.
 
FordGolfer7":24x8v55o said:
An update on the Fuel Problem:

I have replaced the fuel pickup/sending unit, cleaned the gas tank and lines, changed the fuel filter, changed the fuel pump, and replaced the carburetor with an after market. I can get the engine running and drive the vehicle, I cannot get it to idle and have hesitation problems. Could this be caused by distributor problems? I have checked to the best of my abilities for vacuum leaks. Could the PCV valve be a possible culprit? ANY DIRECTION OR IDEAS ON WHERE TO GO NEXT WILL BE GREATLY APPRECIATED!!!

Yes for sure the Distribitor could be a real problem! Have you id the type you have yet? Since you said you had a 1966 Ranchero with a Autolite 1100 carb then it's likely you have the LOM (Load O Matic) system. The good news is it's fairly easy to test it out. Check that the Distribitors Vaccum canister is working as it should by seeing if it holds a vaccum it it doesn't it will need replacement. Also check the Distribitors upper shaft bushing (push the rotor towards engine and then pull it back towards you to see if you can feel any looseness) is it still in good condition? If it isn't then you would probably be better off turning yours in on a rebuilt one. Yes the PCV valve can also cause trouble, with engine runing when you pull it hold your finger over the end dose it move freely? In any case they are relatively inexpensive if you should decide to replace it, be sure to get one that's crosses over to the right part number for your Falcon Rachero. From your description though if you don't have any other Vacuum leaks I would first throughly check out the Distribitors Vaccum canister and the Vaccum line that comes from the carb for its condistion or leaks too. Pull a Vaccum test on it from carb line to the Distribitors Vacuum Canister. How did you set your tuneup specs? Did you use a Tach / Dwel meter and timing light? Good luck in the hunt. :nod:
 
I have tested the vacuum canister on the distributor and everything seems to work fine. The distributor seems to be in good shape. One thing that has been changed is the points have been replaced with a Pertonix system. Is there any way to test this system for intermittent failure? I had to walk away form this vehicle for a little while to let the frustration diminish is one reason I have been so long in responding to your post, again, I appreciate all help and information given on this very aggravating problem.
 
FordGolfer7":2ffkgtqk said:
I have tested the vacuum canister on the distributor and everything seems to work fine. The distributor seems to be in good shape. One thing that has been changed is the points have been replaced with a Pertonix system. Is there any way to test this system for intermittent failure? I had to walk away form this vehicle for a little while to let the frustration diminish is one reason I have been so long in responding to your post, again, I appreciate all help and information given on this very aggravating problem.

:unsure: I hear you on walking away for awhile when you get frustrated! It looks like you have made some very good progress in tracking down, eliminating, and fixing some of the possable causes. So you have replaced the carb with a new one what is it that you used is it one that compatable with your LOD Distribitor? If it's not then you might consider upgrading the Distribitor with the much better DuraSpark II system a simple swap. With the old LOD using the stock timing specs dosent work the best with today's fuels what did you set your base timing too? With these I start with atleast 10 or 12 degrees and tune from there to see what the engine likes. As far as testing the Pertonix if you have a volt / ohm meter you can do some basic tests at room temps and after you have warmed it up good then test it again then compare the readings. You might also test your coils output with the volt / ohm meter too. One other way to test if the Pertronix unit is working correctly is to remove it and instal a new set of points and condesor to see if it runs any better. Also one final question do you have your plugs gapped open to .045? Good luck in your tuning (y) :nod:
 
Hi, sometimes it is good to take a break. So here are a couple of things. Is your replacement carb exactly like what came off, with a load o matic style advance? When you say it won't idle, do you mean you have a very high idle that cannot be adjusted down? Do you have full 12 v going to the pertonix ignition? Did you upgrade to the pertonix coil.
If you have a timing light you can see the timing mark advance when you give the car gas.
Maybe your choke is not opening or for some reason will not come off of high idle.
Maybe there is a vacuum leak
The pertonix coil and trigger in the distributor need 12v, the old resistor wire is no good.
There are 2 different pertronix ignitors for Ford six distributors, the wrong one will not fit or screw down properly. I also find the trigger cam is very tight and not so easy the push on the distributor shaft.
Good luck
 
I'm confused, originally you had an issue and found there was a vacuum on the tank and replaced the carb and a bunch of stuff? Did you ever drive it with the gas cap off with the original setup after you had the initial problem to see if the cap was in fact the issue?

I can't get past the vacuum on the fuel tank, that has to be the answer. Not the carb or the ignition, as flawed as they may be, it was running and then it f*ck'd up and there was a vacuum at the fill cap, right?
 
Ranchero Update:

I will try to address all of the issues and questions:
The fuel cap was an issue, on the vented cap the vent was stuck closed, causing a vacuum. This was replaced and eliminated that problem.
On the problem I was having with the fuel system, it is corrected. I am not sure exactly what was necessary to do and what was done in frustration, but the fuel tank and lines were thoroughly cleaned, the filters, fuel pump, and pick-up - sending unit replaced, and the carburetor rebuilt.
All wiring connections, voltages, and grounding for the Pertonix system were tested, no problems.
The new spark plugs were replaced with newer plugs.
A new set of suppressor plug wires were installed, which appeared to be the major portion of the problem.

Results; Tuned the engine, pulling 19.75 inches of vacuum, however during the fuel issue a stuck float filled the oil pan with fuel resulting in a leaking rear oil seal.
 
Back
Top