TR6 Can't start my TR6

[Nick12]

have a '71 non-PI TR6 which has sat for about two years with occasional starting and drives around the block. To get serious this year, I pumped out the old fuel, replaced with new; dropped the oil pan and cleaned it out, replaced the oil filter and oil. This car has always started fine; even with old gas and after sitting for months but this time no luck. I pumped the lever attached to the fuel pump and noticed bubbles and some, not much, black gunk in the see-through plastic fuel filter with paper element below. After pumping around twenty times, the bubbles went away, the level rose to the top of the filter and I could feel resistance building as the fuel made it to the carbs. Pulled the choke and it started right up. Put it into reverse to get out of the garage to avoid asphyxiation and it stalled. I noticed the fuel filter was now dry and started pumping again—same thing, bubbles but very slow rise of fuel. I decided to stop exercising my wrist and to seek assistance. So here is my question and sorry for the long build-up but this is my first post. I imagine that there is something wrong in the fuel pump that it is not maintaining pressure and is allowing the fuel to drain back down out of the pump and into the fuel lines leading to the tank. Thoughts welcome. I am the second owner; the first was a woman who commuted in the car for about 15 years in San Francisco.

 

[tdskip]

Hi Nick - first of all welcome.

Is there a fuel filter in the back near the tank by chance that you have changed?

 

[TRopic6]

Aloha Nick,

I've had that problem, and it turned out to be a clog at the short tank outlet pipe. Also, rust and other crud can build up in the long horizontal run of the fuel pipe. It's a good place for junk from the tank to settle. I used some copper wire to clean them out. A rifle bore brush will help if there's tar from dried gas.

Jeff
3 x TR6

 

[poolboy]

You may have a problem in the carbs's float chamber. Engines that sit may develop a crust around the float chamber needle valve. It may have gotten stuck as the floats rose with the gas level and stayed there not allowing more fuel to enter the float chamber as the level dropped.
It wouldn't hurt to remove the rubber fuel lines from the nipple on the carbs and spray carb cleaner into the nipples.
The carb cleaner will directly hit the needle valve if you stick the extension into the nipple and blast away.
A few taps with a wrench may also help to jar the needle valve loose along with persistant blasting.
PB Blaster or even WD40 can be substitited for carb cleaner. Results may not be immediate depending upon how much crust is involved.
Just offering an alternative in case there is no actual fuel line blockage.

 

[TR3driver]

The black gunk suggests to me that some "rubber" component has failed; either the diaphragm in the fuel pump, or perhaps the soft lines either at the pump or at the tank outlet. Probably a victim of that new gas having ethanol in it.

 

[Nick12]

Thanks for the welcome and glad there are so many TR6 fans around for novices like me. I'll look for a filter by the tank but I think that the tank filter was only for the Fuel Injected version. If I'm wrong, I'll change that also. After all I bought one from Victoria British years ago and never used it!

 

[Nick12]

Thanks--I think I'll replace all the rubber connectors from the tank to the carbs and clean the pipes along the way.

 

[Nick12]

I'll try this suggestion also. It makes me wonder if I may have put too much oil (or the wrong oil, I used 5-30 motor oil) in the carb dampers. I don't think there would be a connecton between the dampers and the float chambers...

 

[M_Pied_Lourd]

With a bad diaphragm in the fuel pump, you would most likely have fuel in your oil. Check the level on your dipstick and give the oil a wiff to see if it smells like gas.

Cheers,
M. Pied Lourd

 

[Nick12]

Thanks; I'll check that also.

 

[poolboy]

I'll try this suggestion also. It makes me wonder if I may have put too much oil (or the wrong oil, I used 5-30 motor oil) in the carb dampers. I don't think there would be a connecton between the dampers and the float chambers...

No connection. At least none that would keep the engine from starting. There is an O-ring that seals up the oil in the damper and conceiveably if the O-ring were shot some oil could drip down the metering needle, thru the jet and into the float chamber where it could mix with the gas. But as long as you have gas in the float chamber and an arc at the spark plug at the proper time, the engine would start. Even if you lost all the oil in the damper we're only talking 3.5 cc's if you had the proper amount in there.

 

[Nick12]

Thanks for the tips and sorry I have taken so long to reply. Work tends to get in the way of car activities. I followed the suggestions and the car now starts so that is all good. Next question if I may. I removed the radiator cap and it pretty much fell apart--I think it is the original. The catalogue calls for 7 psi for 69-71's and 13 psi for 72 to 76. The one I removed was a 13 psi and I have a 1971, actually built in December 1970. I am wondering if at some point the wrong cap was put on and that may be why my expansion tank never seems to fill or empty. Anyway, is there any risk in replacing a 13 psi with a 7 psi?

Thanks, Nick

 

[AltaKnight]

I would change it for the 7 psi unit providing it's the original engine and not a later year; worst that can happen is that it will strand you on a hot day in heavy traffic with a boil over.
Of courseiIf it ran fine with a 13 psi cap for years why change now.
BTW, it generally works best to start a new thread when you're changing topics.