v8 issues..

[classicalgreen]

having had engine keep cutting out on way to MOT test and back..( it always restarted and ran poorly with no full power available) I assumed I had a fuel issue. so have fitted an electric facet pump from tank to main feed line to carbs keeping original mechanical pump inline. though it is harder to start now.. and won't run . cutting out even more frequently ..I was careful to ensure tank was drained,pipes connections etc clean of debris and fish fuel used . can't even get it out of garage now. assuming carb issues here but both were stripped and rebuilt with kits not long ago.
wil try bypassing mechanical pump and see if it assists. working on basis i have major fuel supply issues from ( or to?) carbs. no sign of pistons sticking in carbs using lifting pins. can't at moment check affect on engine by lifting as it won't run long enough.
has anybody come across this? as fitting new pump seems to have made things worse.. am a bit stumped. but last recourse is my sledge hammer of course though writing off many thousands of pounds worth of classic car is perhaps only a passing satisfaction.

 

[corazon]

will try bypassing mechanical pump and see if it assists.

That sounds like the best thing to do. You could have a blockage within the mechanical pump.
Otherwise have you tried a can of fuel on the roof with a direct gravity feed?
When you refitted the lines to the tank, did they definitely go back on the same unions? If not you would be using the reserve line when you thought you were using the main, and vice versa. Theoretically if you thought you were on reserve ( and you weren't) you could be running out of fuel because the tank level is dropping past the main feed.
Jim

 

[SydneyRoverP6B]

Disconnect the fuel line after the fuel filter and observe the volume of fuel that flows from the filter when the engine is either cranked over, or the electric pump is in action. In both cases, the jet of fuel should rise up quite a number of inches above the filter. If it barely dribbles, then you have a key to the problem. If the flow is as indicated, then the problem is elsewhere.

Ron.

 

[classicalgreen]

many thanks interest . responses are always welcome. after further checking involving jacking up each end of car and removing mechanical fuel pump for a bench test ( OK) then refitted. checked electric pump and it worked ok. so blockage in line indicated.
quick check under hood and found reserve tap ( never connected since I had it,no I didn't disconnect it) was at a different angle to normal. penny dropped..part way open /closed? bit of grunge there maybe?
was unable to undo lower union on pipe to valve .possibly corroded on or badly over tightened. removed the moving part by taking out the small screw on top ( fiddly but ok once free) overcheck showed inner seal was in good nick but outer seal was buggered. changed outer seal. refitted all and with tap now in one position tried electric pump..no fuel supply. swapped to second position an low and behold FUEL.. car now starts almost on button and runs fairly well. might even get to overtake a mil flat at last.
checked fuel lines reserve and main tank..all connected correctly. so far so good. time over weekend to fill up and have the old girl out for a run. short at first see how it goes. if all well..will increase to a decent run of say and hour or two on mixed roads .high speed and traffic. hopefully getting past stage of thumping it with a dirty great sledgehammer.