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TR2/3/3A Fuel Pump No Delivering Fuel

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rckuhlman

rckuhlman

Freshman Member
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Fuel Pump Not Delivering Fuel

My TR3A was running fine, when it just lost fuel and died. After hauling it home, I put in a new fuel pump. I can get fuel when I pump the priming lever, but it will not pump otherwise. I would suspect a worn cam lobe, but it happened all of the sudden. What am I missing?
 
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I would not think the cam is bad. You perhaps got the new one installed on the cam incorrect. The pump lever is below the cam lob and is not hitting.
 
What I find strange is that the original fuel pump seems to be working fine off of the car. I opened it up and the diaphragm is good. So, it wasn't the fuel pump after all, but why would the pump work by hand, but not on the car?
 
Sounds to me like you have a clog in the fuel line leading to the pump. Happened to me last year, apparently too much body shop dirt got into the tank and settled to the bottom of the line. In your case, I'd think it's more like a small rock or perhaps the tank has been "slushed". (The original slushing compound is not ethanol-resistant and sometimes comes off in big sheets.)

Or perhaps the shutoff valve decided to close on it's own?
 
I had a fuel pump that would not work when installed. After removing it and comparing the old and new the lever that ride on the cam was not made the same as the old pump. It he new pump would not even touch the cam. Seem like it needed close to 1/4 inch more in thickness to touch.

Don
 
I'm with Randall. Same symptoms happened to my son on his TR3 a year ago. Turned out somebody had put a toy into his fuel tank and the label came off of it then it would cover the outlet hole when gas started flowing into the line.
Charley
 
charleyf said:
I'm with Randall. Same symptoms happened to my son on his TR3 a year ago. Turned out somebody had put a toy into his fuel tank and the label came off of it then it would cover the outlet hole when gas started flowing into the line.
Charley
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Hmm. Tank blockage has stopped a lot of cars but why does Rckuhlman get fuel with the priming lever? Wrong pimp? You can turn the cam (engine) and measure the lift with a rule through the fuel pump opening. I think it should be a bit more than 1/4 inch. Then put the pump in on the high part of the lobe. You should feel the lobe compressing the lever.
Tom
 
TomMull said:
Hmm. Tank blockage has stopped a lot of cars but why does Rckuhlman get fuel with the priming lever? Wrong pimp?
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I was thinking that the priming lever moves fuel fairly slowly, so it would have time to leak past the blockage; or perhaps as Charley outlined, the blockage moves when the flow is higher. But I could be wrong.

I have seen aftermarket pumps that have a sort of spacer on the lever where it rides on the cam. If that spacer came off (and is laying in the pan), that might explain it. But he said it was an original pump and AFAIK they all had single piece levers.
 
Update - So now I have drained the tank (and managed to get gasoline in my ear, which is excruciatingly painful and dizzying) and see no obvious obstruction. I do see that the tank has some rust, which I will remedy. I was going to take the car up to a cruise, but now it is dead-lined in my garage, so I will have to pull the tank when I return. I am not sure that is the problem, and it is probably not the cam, as I can feel it working when I depress the priming lever while the car is running (which only continues when I use the priming lever). Any other feedback or ideas would be appreciated.
 
Did you blow out the fuel line? If possible also run a wire as far as possible down the line from both ends and blow it out again.
Unfortunately with the tank in the car you are not able to see the area near the outlet and anything near that outlet can just fall to the side and be ready to cover the outlet again. Yes it is a lot of work to get the tank out, but that is the best way to verify there is nothing floating around in there. You can also clean the tank easier out of the car.
Charley
 
charleyf said:
Unfortunately with the tank in the car you are not able to see the area near the outlet
Click to expand...
Interesting ... I never considered that advantage of the earlier tank (where the outlet is directly under the inlet and easily visible.

In my case, I just used an air gun to blow shop air back into the tank. Kind of made a mess, but took care of the problem in a matter of seconds. Turned the remaining fuel black, too!

But I agree, the only way to actually clean the tank is to remove it.

A little late now for rckuhlman, but one of the little electric Facet fuel pumps works reasonably well as a transfer pump, so you can pump at least most of the fuel into another vehicle. Not terribly fast, could take up to 30 minutes to do a full tank, but lots better than getting fuel in your ear (or eyes, etc).

Also a good spare to carry on long trips, JIC the original pump does decide to quit while you're a long way from home. My TR3 pump has never quit, but I keep a Facet pump (along with some clip leads, hose and clamps) in the center of the spare tire, just in case. One of the Stags did have the pump quit, and I was sure glad I had that little Facet in the trunk!
 
Also a good spare to carry on long trips, JIC the original pump does decide to quit while you're a long way from home. My TR3 pump has never quit, but I keep a Facet pump (along with some clip leads, hose and clamps) in the center of the spare tire, just in case. One of the Stags did have the pump quit, and I was sure glad I had that little Facet in the trunk!
Click to expand...

Speaking of electric pumps:
I noticed Another major advantage of an electric fuel pump.
No more preignition run on.

With the mechanical pump, every time the engine turns over (key off or on) the pump feeds the carbs. So if you have hot spots in a cylinder or intake manifold you have a self fulfilling recipe for dieseling, until the hot spot cools down & stops igniting the fuel continuously supplied by the mech. FP.
Not so with the electric pump. Cut the ignition off- fuel stops flowing immediately -no more dieseling.
nothing else I tried worked.

 
GTP1960 said:
Not so with the electric pump. Cut the ignition off- fuel stops flowing immediately -no more dieseling.
nothing else I tried worked.
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Sounds strange to me. Even with the pump shut off, there should be enough fuel in the float bowls to keep the engine idling for quite a few seconds.

I wonder if instead, you might have something leaking power into the ignition circuit while the engine is still turning; like maybe an electric fan or alternator (through the warning light). Adding the load of the electric pump keeps the leak from powering the coil.
 
I wonder if instead, you might have something leaking power into the ignition circuit while the engine is still turning; like maybe an electric fan or alternator (through the warning light). Adding the load of the electric pump keeps the leak from powering the coil.
Click to expand...

i did make a number of other changes between dieseling & non-dieseling, including a replacement wire for the ignition/coil.
(I found the old wire insulation was brittle & burned thru in many places). Also added isolated fuses in a gang box.
So you may be right. I didn't realize the float bowls would continue to feed the carbs without fuel line pressure.
 
Fuel delivery is basic stuff. When you undo the fuel line at the carbs and turn the motor with the fuel line in a canister, does fuel come out? They pump a lot more than they use, and you will know right away if the fuel is adequate. So if no fuel there, the problem is behind that point. Have you had this car for a while? Like Randall suggested, blow some air through line. Has someone added a fuel filter? The problem is most often crap in the tank. Which makes me ask is that you in the picture?
 
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