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Fuel Check Valve?

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Fuel Check Valve?
#1
  This topic is about my 1980 Triumph TR8
Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
Folks:

One thing that is a minor annoyance on the TR8 is the long cranking times after the car sits for a few days. It is not horrible, perhaps 4 seconds, but it is not the instant start I get when the car has been sitting less than 24 hours. My car is carb'ed, with the original Zeniths and richer needles.

I am suspicious that the fuel is draining out of the fuel line and back into the tank. I believe the cranking time is mostly related to waiting for the fuel line to pressurize and then replacing any evaporative losses in the float bowls. I say this because after a long period of inactivity, the car will fire within one second but fail to catch until I crank the car an additional 3-4 seconds. This sounds to me like it fires using the remaining fuel in the float bowl, but then dies waiting for the float bowls to get topped off.

Sound correct?

So, I am thinking if I put a good check valve in the fuel line I can avoid this minor annoyance. Has anyone tried this? Can someone recommend a check valve with which they have had good results? Part number or vendor would help.

BTW, I have the OEM fuel pump setup, but I am using the in tank replacement pump sold by Woody at the wedge shop. It looks like an OEM pump, but I suppose it could have some minor differences from the stock pump.

Thanks,

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore



Edited 1 time(s). Last edit at 2017-10-11 10:37 AM by Darth V8R.

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POW Peter Wirth
HEBRON, NH - New Hampshire, USA   USA
Am I to understand you are using the stock mech pump along with an in tank electric? How can Wood's in tank pump look like OEM? If in tank, it's electric, no?

Bergie Bob Berg
Powell, Ohio, USA   USA
I use a one way check valve on the return line at the tank for my set up...need it to prevent fuel from backing up thru my emissions vent line toward the engine bay...I use a feed and return line set up with fuel regulator.....in pic check valve on right and 85 micron fuel pre filter on left mounted at the tank...6AN fittings...fuel back up not an issue for my set up with double pumper carb-has fuel in bowl even after long period so a squirt with the gas pedal and away it goes...

https://www.summitracing.com/parts/vpe-11187/overview/

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Attachments:
Check valve tank fitting.jpg    44 KB
Check valve tank fitting.jpg

Bergie Bob Berg
Powell, Ohio, USA   USA
correction on pic...top left is check valve with arrow heading back into tank........

Bergie Bob Berg
Powell, Ohio, USA   USA
agree check valve would solve your problem if you plumb it in the fuel line on standard SU carbed car...

https://www.summitracing.com/parts/rnb-800-196/overview/

TR8todd Avatar
TR8todd Todd Kishbach
Mass, USA   USA
1977 Triumph TR7 "Rally Fraud"
1978 Triumph TR8
1979 Triumph TR7
1980 Triumph TR8    & more
I think the original pumps had a built in check valve. Now that they have been superseded a few times, I wouldn't be the least bit surprised if the check valve got lost along the way. I recently installed a new pump and its doing the same thing with a 4 barrel. If the car sits more than a couple of weeks, I have to blast it with starter fluid to build oil pressure to turn the pump effectively. The pump I installed was an old part number for mid 70s GM. Got a couple of them in damaged packaging for less than $20 eBay. Oddly enough, I was the only one bidding, on them so I bought them both.

Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1491410 by POW Am I to understand you are using the stock mech pump along with an in tank electric? How can Wood's in tank pump look like OEM? If in tank, it's electric, no?

Sorry, I was not very clear on that. The OEM setup for the TR8 carb model is the in tank electric pump. I am using an in tank electric pump, but it is the replacement that is available from the Wedge Shop. It looks like an OEM pump, but I am sure by now the OEM pumps are NLA. Woody did a great job finding a drop in replacement, but I don't know if it has a built in check valve, or for that matter if the OEM pump did either.

IIRC, Woody said that his pump kit was pieced together from various suppliers. The fuel sock for example is much bigger than the OEM sock so I know that is not OEM, but perhaps the pump itself is?? Can't say for sure - I just know the original pump would stall and leave me stranded, so I had to replace it.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

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POW Peter Wirth
HEBRON, NH - New Hampshire, USA   USA
In reply to # 1491430 by Darth V8R
In reply to # 1491410 by POW Am I to understand you are using the stock mech pump along with an in tank electric? How can Wood's in tank pump look like OEM? If in tank, it's electric, no?

Sorry, I was not very clear on that. The OEM setup for the TR8 carb model is the in tank electric pump. I am using an in tank electric pump, but it is the replacement that is available from the Wedge Shop. It looks like an OEM pump, but I am sure by now the OEM pumps are NLA. Woody did a great job finding a drop in replacement, but I don't know if it has a built in check valve, or for that matter if the OEM pump did either.


Oh, I am sorry Vance, I apologizes for my ridicules post. For some reason I was thinking TR7 even though I've read enough of your posts to know, first of all, you have TR 8 and secondly, have a lot more on the ball to think you may have added an electric pump while keeping a mechanical one also on line. And if that wasn't enough the heading stating "this topic is about my 1980 TR8" should have given it away. Doh! - Pete

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