Panic Stations!

[Sussex Pete]

OK! Because of all sorts of other issues that have put me way behind schedule, I've only just tried to get a start out of the engine in readiness to take to the NEC in two days from now!

The big problem is that when turning it over without the plugs in, to get oil pressure, I could see fuel being ejected from the spark plug holes. That caused me concern, but then when I put the plugs back in to attempt a full startup, the engine locked to the point that the starter was not turning the engine. Removed the plugs once more and turned the engine over by the crank pulley and immediately got showered in petrol along with the whole of the front of the car. So, basically the engine had hydrauliced to a stop.

Anyone got any ideas as to what I may have done wrong, bearing in mind the engine is fully rebuilt with new belts throughout. An interested passerby suggetsed it may be the ECU, but I don't understand why the fuel was not being ejected down the exhaust.

[mrjones]

When you turn the crank by hand does it turn a full revolution?

[Mike Brock]

yeah you've got raw fuel pumping into the engine as the fuel into the carb is connected wrong. Engine oil will be contaminated with fuel - drain refill with fresh engine oil. Easy fix if you haven't damaged internal engine components?

[Sussex Pete]

When you turn the crank by hand does it turn a full revolution?

No problems with engine spinning over without the plugs in, both before and after the hydraulic stop.

yeah you've got raw fuel pumping into the engine as the fuel into the carb is connected wrong. Engine oil will be contaminated with fuel - drain refill with fresh engine oil. Easy fix if you haven't damaged internal engine components?

Jeff pointed me in the right direction with this Mike. I had got the fuel feed and the cut-off valve pipes the wrong way round (I'm blaming the diagram in the BL manual for this!). Oil drain looks like a must anyway, as I did a compression test after hitting these issues, and couldn't get a reading on number 1. Right s*d to get the tester to screw in, because of the top hose getting in the way, so not absolutely sure I had a seal when testing. So, post-NEC when the pressure is off, I think I will have the head off at least for peace of mind.

[Mike Brock]

It probably was the compression gauge not sealing correctly Pete. Did you do a wet test on that particular cylinder?

[Sussex Pete]

Did you do a wet test on that particular cylinder?

Wet test?? If being full of petrol that is then ejected from the spark plug hole as the engine is spun over, then yes!

[Mike Brock]

lol - I mean pour some oil down the cylinder and check compression again. This could determine possible cause i.e broken piston ring? Likely to be comp gauge not sealing though in my opinion. I would remove coolant pipe for all the time it would take.

[Jeff Turbo]

Could be the amount of fuel in the bores causing this Pete. As Mike says, new oil and put some down the bores as it's been stripped of any lube, and panic over eh

[Sussex Pete]

Got another 5 litres of oil while at the NEC in preparation. With all the panic in the last couple of weeks to get it to the show, I'm a taking a few days breather before I get back to it and sort it once and for all. I've also got a leaking brake caliper (overhauled by Big Red, I think the seal has gone) plus a twenty item snagging list to deal with as well. Hey ho!

[Sussex Pete]

OK Turbo engine experts, I need a confidence boost, please! Since returning from the NEC show, I've taken a break from the car, just so I can look at things afresh. Started again this morning, and first thing was to sort the brake caliper leak and refill with fluid. Just need to bleed to finish that job.

Started on the engine by running a compression test on No1, and all is OK with a good 170 reading. Next thing I want to do is prove I have a spark, BUT I am still (overly?) concerned about the amount of fuel being ejected from the spark plug holes when spinning the engine over. No fuel should be getting to the carb as I have removed the fuse for the petrol pump. So, can anyone suggest what is going on, and how all this petrol is still arriving at the cylinders.

I don't want to drain the oil and put fresh in, if the first time I try a proper engine start (assuming that I have a spark at the plugs) it hydraulics to a stop again because of the amount of fuel in the cylinders. I'm also reticent to power up the fuel pump for the same reason. I know that I have now created an impasse for myself about what to do next, but I've never had a situation like this with any engine I've rebuilt before.

[Jeff Turbo]

Have you pulled the correct fuse? Disconnect the fuel in pipe, reposition outside the car and try again. Or disconnect the fuel pump or pop up the inertia switch. You will have fuel in the bores until exhausted.

[Mike Brock]

The inertia switch is the easiest to isolate fuel pump, but why do you want to do that? I few things spring to mind - is the fuel pipe feeding the float chamber correctly fitted? Is the float valve sticking open? Is the fuel regulator correctly set up? Fuel pressure should be 4psi when cranking engine over. If its lower I would suspect a sticky float valve letting too much fuel in - if its considerably higher then high pressure is lifting the float valve - again letting too much fuel in. Check fuel pressure going into carb - but preferably with the carb disconnected from manifold as you don't want raw fuel pumping into your engine again.

[Jeff Turbo]

The inertia switch is the easiest to isolate fuel pump, but why do you want to do that? I few things spring to mind - is the fuel pipe feeding the float chamber correctly fitted? Is the float valve sticking open? Is the fuel regulator correctly set up? Fuel pressure should be 4psi when cranking engine over. If its lower I would suspect a sticky float valve letting too much fuel in - if its considerably higher then high pressure is lifting the float valve - again letting too much fuel in. Check fuel pressure going into carb - but preferably with the carb disconnected from manifold as you don't want raw fuel pumping into your engine again.

The question was why is fuel possibly still going into the manifold and into the bores as Pete was concerned. If Pete has pulled the correct fuse there shouldn't be any fuel still going into the manifold, if not then popping the inertia switch was a double check that no fuel would be pumping Mike . Once he's cleared the bores then he can check all else, for a spark etc.

[Sussex Pete]

Thanks for your feedback guys!

The thinking behind stopping the fuel flow was to try and isolate the problem causes. I removed fuse B8 (15Amp) which according to the BL Manual is the one controlling the green feed to the fuel pump relay. Certainly without it in, I don't hear the fuel pump running with the ignition on - which is why I raised the question about where enough fuel could be coming from to be seen escaping in large spurts from the spark plug holes when spinning the engine over on compression tests. I would have thought the bores would have been almost dry once the major exodus of petrol happened after the first hydraulicing incident.

As for all the other variables in the fuel system, following Jeff's advice I have changed the fuel feed and the carb vent valve pipes over, so now fuel should be going into the float chamber rather than straight down the venturi. The carb itself has been fully rebuilt by Southern Carburettors including a brand new autochoke fitting, so I would hope that a sticking float is not manifesting itself; the fuel pressure regulator is brand new, so again I would expect it to have been correctly set at the manufacturer.

I will see if I have a spark, using the "spark plug held to the block" test. If that is successful, I would then move to refitting all the plugs and see if the engine still spins over (still without the fuel pump running). If I don't get a repeat of the hyraulicing issue, then I'll drop the oil and fill with fresh and a new filter. Then I'll allow the fuel pump to run and see if the engine will start.

One other thought I had, relates to the fuel tank piping. As these were removed by the "amateur mechanic" with no notes or records, I have reconnected it based purely on what I see and common sense, as in the large pipe on the tank was connected to the inlet of the fuel pump as the pipe diameters are the same, then the small pipe on the tank is connected to the spill return pipe, again because pipe diameters are the same. Was my logic in this correct, or do I need to change these round? None of the manuals (Haynes or BL) give anything to help in this matter.

[Doctordiesel77]

That all sounds logical & the return & pump suction pipes have to be right, or pump would not have pumped all that petrol into the engine...very odd that there is still petrol in engine after all the compression tests etc..