• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR2/3/3A New engine = frustration

Share this page

R

RonR

Jedi Trainee
Country flag
Offline
Over the past several months, I have rebuilt the TR3A engine, transmission ,overdrive, and front suspension; installed a new wiring harness, new exhaust system, new carpet, new door seals, and new door latches. Probably some other stuff that I have forgot.

When the engine was back in the car and the car was driveable, I drove it twice, for a total of a little more than 100 miles. The car has not been started for several months while I did the interior and doors.

Finally, last night I went to start the car, and after primming the fuel pump it started right up. It ran rough for a while. But, after running pretty good for less than a minute at 2000 rpm or more, the engine just died and the tach slowly went down to that sad 0. I have found if I push the gas pedal to the floor when the engine begins to die, the engine rpm still goes down, but then it will struggle around 500 rpm before moving on up to a higher rpm for less than a minute, and the whole process repeats. It did backfire at least once last night, with black smoke filling my garage.

I have around 4 gallons of gas.
The timing, points, valves, and carbs were all set prior to driving it the 100 plus miles.

Any thoughts?
Thanks.
Ron
 
I'd do a quick visual check for loose connections and the like then pull the distributor cap off and inspect the points, rotor, loose connections etc. before checking for a dropped needle in one of the carb pistons.
 
Fuel delivery would be my first suspect. Try removing the float bowl lids after it dies and see what you find inside. Should be enough fuel to hold the float near the top; if the float is near the bottom then you're not getting enough fuel from the tank.

Any chance you turned off the fuel tap and forgot to turn it back on? Will it repeat the performance if you let it sit for a few hours? Shine a light into the gas tank and look for the outlet? (FOD in the tank can sometimes float around and block the outlet, then float away and unblock.)
 
Perhaps a blocked fuel filter or line. Try changing the filter and removing the fuel line before the filter and blowing compresed air backward into the tank. The long sit before the problem developed suggests sediment.

Bob
 
What color is your rotor? Get a red one. There were black rotors which had either too much carbon in the plastic compound or a loose rivet which caused a short and symptoms similar to yours.
 
Black backfire sounds like it's loading up from getting too much fuel rather than too little. So, float level...fuel pressure...choke assembly would be my first checks. At this point it also sounds like your plugs are fouled, so they will need cleaning before trying again.
 
Thanks for the suggestions. I will check them out this evening and report back.

No fuel tap in the car.
It does repeat the same problems after several hours of sitting.
New fuel tank, but will check inside anyway.
No fuel filter (I bought one to install but can’t decide on the best location. Suggestions appreciated)
Advance Distributers red rotor, of course.
I will check the choke and clean the plugs. I have an aggregate blast spark plug cleaner.

Ron
 
The last tr3 I did I put a new fuel tank in from a southern Cal gas tank specialist and that put about a tea spoon of weld byproduct into each bowl. In addition, I keep about 3 sets of plugs around until I get things sorted out. Do the old unhook the fuel line and see the fuel pressure. I think somewhere somebody here has mentioned the problem, and sometimes the problems are plural.
 
RonR said:
Thanks for the suggestions. I will check them out this evening and report back.

No fuel tap in the car.
It does repeat the same problems after several hours of sitting.
New fuel tank, but will check inside anyway.
No fuel filter (I bought one to install but can’t decide on the best location. Suggestions appreciated)
Advance Distributers red rotor, of course.
I will check the choke and clean the plugs. I have an aggregate blast spark plug cleaner.

Ron
Click to expand...

If there's no filter at all, there's a good chance your getting junk blocking the float valve spuratically, so the bowls over-fill.
 
What is the best location fo a fuel filter on a TR 3A?

Prior to the engine rebuild, I did drive the car for several years with the new gas tank and no fuel filter.
 
Update:

No fuel in the float bowels. Floats set correctly and needle and seat working properly.

No blockage in the fuel line between the carbs and fuel pump.

Fuel pump glass bowel was full of pure clean gas.

I removed the fuel line from the tank to the fuel pump and gas flowed freely the full area of the fuel line.

Cranking over the engine with the fuel line removed from the front carb float bowel, there is a very small and slow stream of fuel from the fuel line.

My guess is the there is either a blockage in the fuel pump, or my wonderful Victoria British 4-year old fuel pump has decided to stop working.
Since the car ran great for over 100 miles, I don’t think the fuel pump arm was installed incorrectly onto the cam shaft during the engine reassembly.

Thoughts?
Thanks.
Ron
 
Yup, sure sounds like a problem in the pump. Should be a very definite spurt at the outlet, as the pump only puts out fuel on every other engine rotation.

I ran for many decades with only the stock "filter" (the sediment bowl plus the screen in the top of it). It lets very little crud through. Only time I had trouble with float valves getting blocked by crud, the crud proved to have come from the soft lines near the carbs (which IMO should be replaced every decade whether they need it or not :smile: ).

However, I did finally install a paper element filter after finding some very fine silt outside the carb jets. (Very likely debris from having the car painted with the fuel cap off. Next time I'm going to plug the tank shut myself ! )

BTW, the sediment bowl should stay full even when you're out of gas. The outlet is deliberately at the top (so it doesn't suck up any water or sediment in the bowl). So even if the pump is sucking air through the bowl, the air just goes inlet to outlet and the bowl stays full of fuel.
 
TR3driver said:
...However, I did finally install a paper element filter after finding some very fine silt outside the carb jets...
Click to expand...

This is the one I use on my non-TR - should also work on the TR3-4 fuel bowl:

https://www.bpnorthwest.com/fuel-filter-glass-bowl.html

C28080.jpg
 
RonR said:
Update:


Cranking over the engine with the fuel line removed from the front carb float bowel, there is a very small and slow stream of fuel from the fuel line.


Thanks.
Ron
Click to expand...

Have you removed the outlet line from the fuel pump and then cranked the engine?

David
 
Maybe the valves in the pump have stuck shut with varnish. I'm just reviving a 56 Buick that needed the fuel pump taken apart and cleaned.
 
Back
Top