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TR2/3/3A Tr3 fuel pumps in the mountains.

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sp53

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Hi tr3 people first let me tell you my set up. I have stock S.U.s and an A.C. fuel pump so the vehicle is stock except for a fuel filter back by the tank. What happened is I was driving up Chinook Pass in Washington (5500ft) and was about 100 yards from the summit and the car starts fading out. I pulled over shut it off then started it back up figuring the bowls had run dry. The car starts up but fades out again. I thought oh this must be connected to the mountain, but I kinda panicked. Perhaps if I had used some patients the problem might have gone away. BUT I undid one of the top on bowls and it was just about dry, so I blew the needle out and thought well I will try and start it. It did not start. Then I undid the fuel line at the float bowl and cranked on it. The gas spurt was just kinda whippy and I could not tell for sure if it was really working.
It was becoming unfun. The gal with me said maybe that thing (the pump) is clogged, so I thought it might be the little brass screen in there is clogged, plus I could show her how cool I am (was) by popping it out. Well, when I got the bowl off the pump and looked at the screen it was ok. However, the rubber ring and somehow enlarged and it would not go back in place. Then it dawned on me that I had put a fuel filter in the back in the trunk. So back to the trunk I go with my very small tool kit. I could remove the filter, but what would I put in its place. Karen had an ink pin, so I used that, but the plastic started getting sticky. It just looked too dangerous, so after asking the nice people who stopped if the had a piece of 5/16 pipe about 3 inches long. I thought well I could cut off the little nub on the end of the old fuel filter and stick that in the gap. I did and it worked. The story goes on.

Back at the fuel pump the rubber would not go in) I do not know why it expanded and would not shrink) I must have been afraid of trying to cut it down. But after a while and being stoked with manic adrenalin I starting stretching vinyl tap over the lip of the bowl moving it around and it worked. By this point, I had basically given up and figured the pump was dead, but that just did not feel right. I keep cranking on the motor as we set and waiting for the wrecker. And then like magic a little spurt came into the bowl. It was funny; Karen got all exited like it was Christmas. I thought this thing is going to run. It started and I drove it home with the blessed Haggerty Insurance wrecker coming up the mountain to rescue me. I was able to honk at him and he turned around and we worked it out in Eatonville.

Anyway after that long context here are some of my questions. Should that stock fuel pump have been able to adequately pump the amount of fuel needed going up a mountain on acceleration with no problem? Could the fuel filter in back slow down the pump even if it was not clogged? And finally does the class bowl have to be sealed up on the pump for the pump to work.

Thanks George
 
My TR3A is totally original. I drove to VTR in Portland Oregon in 2000 via Yellowstone National Park (7225 miles) and no problems as you experienced. In 2001, I drove to VTR in Breckonridge Colorado (5225 miles all told). In Loveland, I leaned out the mixture by turning up the hex adjustment on the bottom of both carbs by two flats because of the altitude (5000 ft) and carried on up Estes Pass (12,095 ft) with no problems. Power was down, but with less oxygen, I expected that. For a week, I drove around Breckonridge, Vail, Aspen at about 10,000 ft or more with no problems. My mechanical fuel pump worked fine. It is the original one that came with the car in 1958 as are the diaphragm and screen etc. for the filter. On the way home, I reset the hex by 2 flats on the bottom of both carbs to the setting they had before. I did this I got down to Boulder.

Don Elliott, Original Owner, TS 27489 LO

https://www.britishcarforum.com/ubbthreads/photopost/showphoto.php/photo/1977/cat/517

https://mysite.wanadoo-members.co.uk/trebor/don3a_big.JPG
 
Hi Don and thanks I enjoy reading your replies because you bought yours new, not many people can say that. The nice part about that is I feel your replies are the horse’s mouths answers. Not many original cars left and I have never had the pleasure of driving one new, so I really appreciate your input. Logically, I figured the car should race right up that mountain. Perhaps my pump is weak and I should replace it. However, for now I think I am going to leave the back filter off for while, replace the rubber at the pump, drive it around, and perhaps put that Canadian fuel pump I bought in the spare tire hole.

George
 
George,
I know that most TR owners who use a filter do so after the fuel pump. A good reason is that the fuel pump doesn't have that much sucking power.

Did the filter have any gunk in it when you took it out?

Sam
 
[ QUOTE ]

Anyway after that long context here are some of my questions. Should that stock fuel pump have been able to adequately pump the amount of fuel needed going up a mountain on acceleration with no problem? Could the fuel filter in back slow down the pump even if it was not clogged? And finally does the class bowl have to be sealed up on the pump for the pump to work.
Thanks George

[/ QUOTE ]
Hi George,
The answers are yes, yes, & yes.
D
 
Hi Sammy yes the filter had a kind of rust brown in it. I had the fuel tank out of the car a coupe of years ago and it was my best looking tank, very solid. I put the filter before the pump because I was trying to lengthen then the life of the pump by keeping the impurities out. My old fuel pump buddy who must be 90 (I think he might be gone now). Cool guy maintained that an A.C. puts out about 2psi but sucks about 50. The 50 pounds of sucking always seemed too high for me, but he had worked cars for many years in the day, so I just accepted what he said as truth. Yes Dave I was kinda thinking that they could be all yes. I guess the seal on the bowl creates the vacuum?

George
 
Aloha George,

The fuel pump on the TR3 is mounted lower than the bottom of the fuel tank. Gravity provides positive fuel flow to the pump generally. After a long lay up for some major repairs, I rolled the car out of the garage to start it. The nearly empty fuel tank and the slight incline of the drive way (rear of the car down hill) made it impossible to get fuel to the fuel pump. A few gallons of gas added to the tank solved the problem.

A leak in the suction side of the fuel system will degrade fuel delivery. A leak at the bowl gasket would have been a cause of the problem. IMO, the fuel filter near the tank was the principle cause of the problem. I would replace the filter with an in line filter with a replaceable filter element like this:

https://www.napaonline.com/cgi-bin/ncomme...p;usrcommgrpid=

If the filter gets clogged on the road, you can either replace th element or remove it from the housing if you don't have a clean element.

Safety Fast,
Dave
 
For whatever it's worth, I like my fuel filter up in the engine bay, just before the fuel pump if possible. But I've also come to appreciate that even when a fuel filter doesn't look clogged, it can be. Much of this season's running of my Herald, I'd been meaning to play around with things as I felt it was really only running about 97%. But after a failed trip and a quick, desperate ripping out of fuel filter and replacement with nothing but fuel line, the engine's been running more like 99.99%. I've not yet gotten around to replacing the filter, although I suppose I should.

It looked just fine, by the way....
 
Hi Dave and thanks I think I will move in that direction. Tell me though do you think an additional filter by the tank will effect performance. I mean does a guy really need it. We have that screen at the pump and those two little screens in the carbs. In addition to that, it looks to me like a grain of sand would just go right through an S.U. get smashed by a valve and go right out the exhaust.
George
 
Hi Andrew and yes I am experiencing the same thing. I am driving with the filter out and I think the car is actually performing better. That little two percent is really messing with my plans to put a filter back in or leave it out. It is torture because it might be all in my head.

George
 
[ QUOTE ]
It is torture because it might be all in my head.

[/ QUOTE ] For me, it wasn't just "in my head"! Truth is, there's little difference in acceleration or "pulling power"; on the other hand, at typical part-pedal "cruise," the engine doesn't have the ever-so-slight hesitation and/or misfire that it seemed to have before. Oh, and fuel mileage does seem up just a bit as well. /ubbthreads/images/graemlins/driving.gif
 
Aloha George,

I had a filter in my MG between the tank and the pump. I removed it because it was constantly causing fuel starvation problems. In retrospect, it was over kill, there is a screen/filter in the SU electric fuel pump, screens in the carbs so I concluded I had deadly fuel filter build up. Once I removed that filter the fuel starvation problem went away.

In my TR3 I have a fuel filter just before the fuel line enters the forward carb. I have not had a fuel flow problems with this step up. I also did this to my MG without a problem. I think the fuel pump push fuel better than they draw. As Andy pointed out, in the engine bay, it makes it much easier to observe the filter and changing it is easier.

Safety Fast,
Dave
 
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