[Bulldog 61]

ozzycouch wrote:

Try disconnecting the pump and letting it run for a few minutes before turning off.
Then hook it back up to restart at the 20 min mark.
Will at least eliminate fuel getting forced through the carb causing flooding with residual pump pressure.

Yeah Ill give it a shot, its easy enough to get at and only one wire.

cheers

[Bulldog 61]

Gwagensteve wrote:

I can't think of a reason to run anything other than a mechanical pump on a G16A/G13A/G13BA. They seem to work perfectly for ~25 years, are completely maintenance free, don't add to electrical draw, aren't introducing power wires and connections under the car, don't have safety issues related to pumping whilst the ignition is on (a tachometric relay via the coil is the correct way to install one, not via the IG+ circuit in my opinion) deliver plenty of fuel to a stock engine at the correct pressure, and utilise the return line.

Is your return line free from obstructions? you could have replaced one problem for another.

are you 100% sure you have no damage/tiny weeps in the fuel lines anywhere? This could cause the system to draw air with the electric pump down near the tank as it cools.

Nothing hard and fast, just things to check.

Just a thought, is your carbon canister correctly connected and the vapour system flowing properly? I wonder if you're pulling a vacuum/pressurising the tank? I seem to recall Christover having some sort of problem like this.

Steve.

Your probably right about why an electric pump, truth is it was there already and worked fine, if I run the mechanical it seems to be passing oil into the mix as it blows blue smoke.
The return line is free, I had checked it previously thinking this might be causing the flooding issues when I tried just the mechanical pump on its own.
Definitely no leaks in the system, at least that I can see anyway.
I did notice a slight vacuum in the tank when I released the cap this morning, but surely if this was the problem it would also be a problem after a couple of hours running?

Its getting to the stage were I will just buy a new mech pump and hope it fixes it, do you what are the genuine pumps worth by any chance??

[Gwagensteve]

Sierra genuine ones are circa $130 - vitara should be similar. Do NOT buy an aftermarket pump - they last no time at all.

[Bulldog 61]

Gwagensteve wrote:

Sierra genuine ones are circa $130 - vitara should be similar. Do NOT buy an aftermarket pump - they last no time at all.

thanks for the heads up

[Bulldog 61]

Its Friday afternoon so its time to start the diagnosis again. Fitted a second hand coil I had laying around looked to have a better spark but it could just be me grabbing at straws. When it wouldn't start after a bit of a run and being stopped for 20-30 mins I tried running a wire direct from the + battery terminal to the + coil but it was no help. Checked the fuel tank for pressure and was just a pffft when I cracked the cap. I have since after getting home left it run for a couple of minutes with the pump disconnected as Ozzycouch suggested and will see what happens in 20-30 mins. Is there a way to test the mechanical pump on the engine currently? Might have to bite the bullet and shell out for a new mech pump......Im running out of ideas.

Just a thought what if the condenser is dodgy ?

[Bulldog 61]

Bulldog 61 wrote:

ozzycouch wrote:

Try disconnecting the pump and letting it run for a few minutes before turning off.
Then hook it back up to restart at the 20 min mark.
Will at least eliminate fuel getting forced through the carb causing flooding with residual pump pressure.

Yeah Ill give it a shot, its easy enough to get at and only one wire.

cheers

I tried this just now and low and behold the car started after 2 cranks though I must admit it may have been a bit more that 20 mins sitting being beer o'clock. I going to give it another shot later tonight if possible.....assuming it does work are we saying elect fuel pump is the problem?

[Dan`]

firstly as good as it is, it stating once may have been a coincidence. dont count your chickens just yet, tho crossing of fingers and toes are advised....
its not the electric pump being the issue, its not having a return line while using the elec pump that is more likely to be the issue. maybe you have a T piece laying around that you can T into the fuel line near the carby and plumb the return line back in?

congrats on at least having a small victory, its frustrating as hell chasing non obvious issues.

[Dan`]

what im thinking is happening is that the pump builds up pressure and not releasing it when you turn the car off. when you stop the motor that pressure very slowly bleeds past the needle and seat, say a drop a minute (just as a figure to explain what i think is going on) and your float bowl only has a certain amount of space left until it overfills and overflows dripping raw fuel into your inlet mani. this is why you dont see any issue at any other time then the magic 20 min mark. at that point is when its finally filled the flat bowl and overflows.

think of it like a slowly filling bath tub, you can leave the tap dripping for a while but eventually its going to overflow the capacity of the bath and your going to have water leak elsewhere.

[Bulldog 61]

Dan` wrote:

firstly as good as it is, it stating once may have been a coincidence. dont count your chickens just yet, tho crossing of fingers and toes are advised....
its not the electric pump being the issue, its not having a return line while using the elec pump that is more likely to be the issue. maybe you have a T piece laying around that you can T into the fuel line near the carby and plumb the return line back in?

congrats on at least having a small victory, its frustrating as hell chasing non obvious issues.

Yeah it was a short lived victory, second attempt was back to not starting. I see what your saying about the return line but remember I did have the same starting issue running off the mechanical pump (both by itself and with the elect pump in series) that's still bolted to the motor with all the lines connected correctly.

[ozzycouch]

Worth a shot. My thinking was that the valve stopping the fuel bowl from over filling may still have a bit of crap in it holding it open. Any pressure in the system while the car is turned off will flood the engine, stopping it from starting. If your really keen, do the fuel pump disconnection, park it up hill and take the fuel cap off. That will get rid of all the pressure and stop it flooding... If that's the problem.

[Bulldog 61]

I changed the carbie over to the webber that was on the 1.3 motor that was in the car when I bought it and low and behold on the mechanical pump only it ran great and started every time I tried it. Im going to change back to the electric pump only tomorrow and try it again to confirm its not the electric pump causing the issue, or at least its elect pump with the standard carb that makes things unhappy.

Thanks all for all your help and suggestions, I will keep you posted.......you should see the smile on my dial atm. Its beer time

[ozzycouch]

Good work, glad you got it sorted

[Bulldog 61]

all is well, electric or mechanical it starts no problem not matter what the engine temp is, Im loving the weber atm I just hope it works ok offroad. I will get an OEM mech pump and use the electric as a transfer pump for my auxiliary tank.

Thanks everyone for your help and suggestions.

Just a side note I spoke with the guys at Re-carb today and they reckon a fuel regulator set at 3psi would also have stopped the flooding and fixed the problem.