Having trouble restarting engine


Well-known member
I'm still having trouble restarting my Mustang 200 with Autolite 1100 after it sits for 15 minutes after I have driven it somewhere. When trying to restart it pumping the accelerator or spraying starting fluid in to the carb makes no difference. I cannot visually see any fuel leaking down carburetor. Removed the top of the carb after letting it sit... has plenty of fuel in the float bowl does not seem to be boiling over or losing gas. Float level is set to 1 3/32" as per instructions. Removed fuel line from pump to carb after car sits for 15 min and it was bone dry. The thing is my engine is not running hot, it will do this when it is 45 degrees outside and I have the original metal carb to pump line. I don't see how it could be vapor lock. Why would it be going dry? it seems fuel may be draining back into the fuel pump. Fuel pump is replacement from Autozone and is my second fuel pump, thinking it was the source of my problems but did not fix anything. Car has difficulty restarting but will always restart after 8-10 cranks then runs rough and has a hesitation when accelerating from a stop and will run fine after about 20 sec. of idling or driving. Ignition is a pertronix, new 12v coil with full 12 volts, and all other tune up items are new It never gives problems while driving. My last resort is to bypass the heater hose from carb baseplate and see what happens. Its really getting frustrating dealing with this.
Well Mine was doing pretty much the same thing but it did seem to be some what heat related. Once the engine temp. got over 190 degrees the problem would show up. Hard starting stalling when taking off. Onced cleared up it would run fine. Going down to a 160 degree t-stat helped. My latest idea was to scrap the carb and go with a tripple offy set up. Still working out some of the bugs so I am not sure if the problem is solved yet.
i was thinking of removing the radiator tubes from the base of the carb. That way, the hot coolant (oxymoron) wouldnt heat the carb.
I know this sounds stupid, but have you checked the Choke Unloader. Is that adjusted properly. That can cause hard starting while warmed up.

err..what'sa choke unloader? never hear THAt before.

I am just gonna go to the Carb Shop.
Could be a problem with the starter. Heat soak on those older starters can cause them to go bad. You can get a reman for like $60 and it's an easy swap.
Engine cranks fine, I am absolutely sure it is not the starter. I am running out of ideas on this one.
I had virtually the same symptoms, turned out to be the starter. Started fine when cold, but when it had sat for ten minutes after running, was very hard to turn over. Removed the starter and one of the long bolts through the hole starter had stripped. Replaced it with a new bolt and now it cranks every time, very fast. Even when it might be hot starts right up.
i had the EXACT same problem... now for me it was 1 of 2 things (not sure which one since the starter mechanicaly exploded a few weeks ago and i had to get a new one, but try backing the timeing off a bit, i found that it made the car MUCH easier to start when hot
Car has difficulty restarting but will always restart after 8-10 cranks then runs rough and has a hesitation when accelerating from a stop and will run fine after about 20 sec. of idling or driving.

With this type of symptom after you get it running I doubt it is the starter... If it was it would then run fine once it was running....
This sounds like it has to be a fuel problem... and it sounds like you are not getting fuel once the car is shut down. Even if you spray into the carb it may fire once or twice, then die... if you keep pumping and turning the gas finally comes up the line....

You mention replacing pump, carb, etc.... out of curiosity what is the status of the rest of the system going back to the tank....

How is your line, sending unit, and tank....
Could you have a clogged screen or something in the tank?

Just a thought, someone who knows more about fuel and carbs might be able to tell you why that line is dry, but I think if it was mine, I would say you have a leaking fuel line, the car runs, then the fuel leaves the line and you have to pump it back through again.... it may not be enough to get fuel on the driveway, and if it was it would evaporate very quickly...

How is your fuel economy?

Let us know how these systems are...

but it seems to me something is causing those lines to empty when you shut her off... otherwise there would be fuel in there.... it always pours out of mine when I remove it.... I also installed a later post 68 pump that has no filter on it... and installed a line filter.
I replaced the fuel line from tank to fuel pump with 5/16"steel tubing properly bent to the original configuration . Tank is a clean original unit. I am sure the screen in the tank is clean because it never ever gives trouble while driving, I have been in many old cars that have stalled due to clogged lines and dirty tanks and it doesn't display those symptoms. As jimbo65 stated this is a fuel related problem. My starter cranks fine and my timing is not off causing the engine to crank hard. I can crank the engine with no problems but it will not fire if left to sit for 15 min. My gas mileage is not great, I have not calculated it but it is no more than 15 mpg at best estimate. I think I can pretty much rule out the igniton as it is all new components and in tune, I even checked to make sure TDC was right on the balancer. I also ran a spark voltage meter on each plug wire and I get a consistent 10kv on all six wires. I am going to try increasing the float height and see what that does.
The two replacement pumps I got from the zone have no integral filter, I believe the '66s never had an integral pump and filter. I would have preffered to rebuild the original pump but no one had kits for it. I am also positive I have no external leaks in the line and I see no evidence of a pierced pump diaphram leaking gas into the crankcase.
I had a similar problem. Did all the stuff you did. the fuel just seemed to run back into the tank every time it sat for a little while. I finally ran a neoprene or rubber hose from the pump to the carb and installed a check valve in it. The valve cost about $8.00 but it solved the problem for me. Good luck.
Is the fuel vapourising, and largely forcing its way back? Just a thought.

Regards, Adam.

It sounds like vapor lock to me, but you've been through that already. Also sounds like backpressure or a vacuum is being created in the system emptying the line between the pump and the carb, which might point to the sending unit (You may want to check the screen just for grins). Or it could be that the pump isn't maintaining pressure when the engine is shut off. The simplest solution may be, as Marlin said a check valve, or what a plumber calls a back flow valve. Then the next question is placement, you could put it at the carb if fuel is emptying out of the bowl, or at the pump if fuel is emptying out of the line, or at the sending unit if the fuel is flowing all the way back to the tank.
I never did check the screen. When I got the car I drained the tank and flushed some fuel through it and the inside of the tank looked extremely clean so I left it alone. I also blew air through the line to check for obstruction but it seemed good. I did have a clear inline filter, which stayed clean, just before the pump but I removed thinking it might be interfering with the pump suction. The filter always stayed full after I shut the car off and even for months. I checked to see if the filter may have been accumulating the fuel draining back from the carb to pump fuel line but I didn't notice anything unusual. I bought some new metal line and a new filter for the carb and I am going to see if I can route the line any better away from heat sources and check the tank screen. I am pretty sure the problem is heat related but it seems to not take much heat to make it do it.
i would heck your Coil the engine is running fine and when you shut it down it wont fire agian, the coil could be heating up and breaking down i would replace it not to much $$$$. also check points and codencer.