After my previous issues with vapor lock (yep you were all right) when we got back on the road after 2 months of mostly staying still I started to have similar problems again. Spirting and stuttering and cutting out. I thought damn vapor lock again, but looking at it the engine temperature, sometimes it really was cool.
So changed the fuel filter (again) which had got quite dirty (again). Seemed to fix it. But a few days later it came back. Only after high workloads such as driving at high speeds for sustained periods of time or heading up steep inclines (which Bolivia has by the truck load). After a 10 minute break we'd be back on the road with no problems for a while.
Ok so 90% sure it's not vapor lock, must be clogged lines or bad fuel pump. At one point I had to drain fuel from the tank put it in a fuel safe bag and make a gravity feed directly to the carburettor to get up some of La Paz's mountainous inclines.
As I'm low on tools took it to a mechanic (bad idea) where un-knowledgable apprentices using an electric fuel pump managed to bypass the fuel tank return feed and send I assume high pressure direct to the carby, after which fuel was leaking out (hope no serious damage was done) - you really have to watch everything mechanics/workers do down here, it really is just worth buying enough tools to do EVERYTHING yourself. The car ran fine with the electric pump after everything was set up right. But I wasn't totally convinced as the prob was intermittent. Convinced them to take out the mechanical pump and found that one of the diaphragm seals (I think that's what they're called) was a little hard. A little loosening and back together and so far we haven't had that problem again (yet).
I got hold of an electric pump just in case the mech fails again, but it is small only giving 8-9 psi. Is that enough pressure? I remember reading somewhere on here that 6-7psi is needed but maybe with the length of the lines etc the pressure would drop too much.
What's the general consensus on electric vs mechanical pumps?
