I've been scouring the forum for similar issues. Yesterday at the HERO Regularity rally in Chesterfield my trusty Sprint coughed and spluttered then died going up a hill. Having done my limited best to determine the fault, the backup maintenance crew arrived on scene. They quickly ruled out electrical and focussed on fuel supply. Like magic in 15 mins they bypassed my mechanical fuel pump and fitted a temporary electric pump (& new filter) under the bonnet. After some priming difficulty, up it fired and we were good to go. We tore off to the next Stage only to encounter a significant hill again. All was fine (even great really) until near the top again when the same problem recurred. Given the time of day, we bailed and headed back to the trailer...which was easier to write than do. Every hill we came to we either had to back down and find another route, or slowly limp up - spluttering all the way. So... On level ground I can give the car full beans with no issue at all
. As the road inclines uphill I get the odd cough which, the steeper the incline, can be terminal. It is totally incline related. This is the part that I can't really understand. If, I was pulling air into the fuel line what would a hill have to do with it? Could I be pulling air into the tank outlet (within the tank itself), this might make sense with a half full tank? Could there be a bit of crud which only blocks the outlet on an incline? Theoretically this could have been disturbed on one of the fast gravel tests - I did bottom out pretty heavily a couple of times! I'm a bit dubious about this because it's not random at all. Just incline related.
I note that the electric pump in the bonnet has the same suction distance as the mechanical pump. So maybe change out the whole fuel line. I guess emptying the tank for a good look see makes sense too.
The incline bit has me baffled though....and the fact that it seemed to get progressively worse. By which I mean that it had happened earlier in the day. I switched spark plugs and all seemed good (though obviously it was just the rest it wanted
). We managed another 2 regularities and 4 gravel tests at full beans, without issue. Then the second regularity after lunch the problem I described above re-appeared and then just got worse.
Perhaps all the banging and shaking on the gravel tests? Err.... Ummm..
And advice would be most welcome