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Over fuelling / won't turn over!
ChrisL - 31/12/11 at 11:04 AM

Apologies for the cross post from the tigers OC forum:

I'd noticed an issue when starting my car with a loud bang. Following a conversation with a friendly face where it was suggested that I was getting hydraulic lock!! So I've pulled the carbs off and found that the manifold on #3 is full of petrol, the inlet valves are closed. I've taken the float chambers apart and the floats and inlets look ok, so I adjusted the float valves so they stop filling earlier. The carbs were already at the correct angle. Next step took the plugs out, #3 looks to be too rich, which would line up with the excess of fuel. Fuel system has a pressure regulator which I've not touched, on the basis this could just be an issue with one or two carbs. I then tried to turn the engine over with the plugs out. The idea being that it will blow out any remaining fuel, however car won't turn over. So bought a battery charger and left the battery on charge over night. Just tried again (with plugs still out) and she still won't turn. I'm currently charging a spare battery possibly to jump onto the existing battery for lot's of current. But I'm concerned that she won't turn over with a fully charged battery, I guess it's possible that in the last month the battery has died. Any thoughts?

theconrodkid - 31/12/11 at 11:11 AM

are the cylinders full of fuel? (this may have drained by now and the sump over full with oil?)
if you did get a hydraulic lock i can bend a rod,that will stop the engine from turning.
put it in forward gear and push the car backwards,cold be as simpe as a starter problem,try the simple things first

MikeRJ - 31/12/11 at 11:13 AM

Does the engine turn over ok if you put it in gear and push car forward?

daviep - 31/12/11 at 11:16 AM

What happened when you heard the loud bang?

I would try to turn it over by hand ( spanner on crankshaft ) using the starter is a bad idea.

If it won't turn any further in the correct direction will it turn backwards?

If it goes backwards turn it back towards the spot it stops at and note how it stops - does it get slowly tighter or does it stop sharply?

Report back

Davie

EDIT: Just noticed you are running bike crabs, what fuel pump are you using?

Fuel pressure regulators are notorious in my experience for not regulating down low enough, simplest/most reliable solution is the bike pump.

[Edited on 31/12/11 by daviep]

ChrisL - 31/12/11 at 12:57 PM

The loud bangs happened the last couple of time I cold started, I mentioned this to a friend and he suggested hydraulic lock. This lead me to taking the carbs off and discovering the fuel in the inlet manifold. The oil level is correct, so I don't think the excess fuel hasn't made it down to the sump, nor is there any fuel in the cylinders. When trying to turn it over, with the plugs out there isn't a loud bang it just won't turn over, either on the starter or by rocking, in gear. However she did turn over initially.

Next step I'll try is turning her over using the crank when I next have a chance to get to the garage.

Cheers for the advice guys and a happy new year to you!

MikeRJ - 31/12/11 at 01:21 PM

Loud bangs won't be caused by a hydraulic lock, much more likely that either the timing is out or it was simply fuel in the exhaust igniting.

ChrisL - 31/12/11 at 01:26 PM

quote:
Originally posted by MikeRJ
Loud bangs won't be caused by a hydraulic lock, much more likely that either the timing is out or it was simply fuel in the exhaust igniting.


The bangs only ever occurred if the car had been left standing for a few days. They sounded like a loud mechanical coming together. The engine then wouldn't turn over and there was the sound of something loosing pressure, a hissing. Eventually, by bump starting (bearing in mind this is at 5 AM, so it's a case of get it started quietly and get going!) the engine runs fine, plenty of power, al,so starts fine for the rest of the day...

ChrisL - 31/12/11 at 02:14 PM

Hmmm, not good won't budge in either direction, trying to turn the crankshaft. Did think it was going OK in one direction but it was only the crankshaft pulley bolt unwinding! And car was in neutral and the plugs are out :-(

rusty nuts - 31/12/11 at 02:47 PM

Might be worth taking the starter off and then try rocking the car in gear?

gottabedone - 31/12/11 at 03:30 PM

any mechanical "bang" isn't something that i would want to re-create too often

Is the hiss from the top or bottom of the engine - what state is your oil/water in?

Steve

jacko - 31/12/11 at 03:37 PM

Bottom end coming apart and jamming ?
timing belt jumped and valves hitting the pistons ?
looks like you need to be careful before forcing things

ChrisL - 31/12/11 at 05:08 PM

Tried turning the crankshaft with the starter off and no movement, admittedly left the car in gear (d'oh) but I'd still expect to have a little movement.

Not sure where the hissing was coming from, but given the amount of fuel I found in the inlet manifold, I'm fairly certain that the bang was hydraulic lock and the hissing is the fuel escaping form a pressurised cylinder head.

Oil and water are both normal, levels and fluid.

So what's my next step in the investigation, head off??

Cheers for the help

Chris

Simon - 31/12/11 at 06:15 PM

If you have got bores full of fuel, you'll want to empty them first. Bucket under engine, inlet manifold off DISCONNECT IGNITION system if you have fuel in the wrong places (ventilation in garage etc etc), spark plugs out - then turn engine with spanner on crank nut. May be worth chucking a few drops of oil in bores, then spinning on starter. Petrol will remove oil from bores so spinning would be bad without any.

Once engine is cleaned of petrol and lubed, then start investigating why it filled with fuel - preferable without putting inlet stuff back on till you're found the fault.

ATB

Simon

rusty nuts - 31/12/11 at 10:03 PM

If there is no movement of the crank even with the plugs out and the starter has been removed then the crank is likely to be siezed or locked up, if there is some movement then it's likely to be pistons . Possibly caused by the oil being diluted due to bore wash. Bent valves normally allow the crank to rotate at least until the pistons near TDC.. My guess would be a main bearing has spun jamming the crank

ChrisL - 1/1/12 at 01:44 PM

I think you're probably right, guess the only way to find out is to strip the engine down :-( Wondering if now's the time to pick up a crate 2 ltr blacktop!

jacko - 1/1/12 at 01:52 PM

Sounds like strip and search
Jacko

ChrisL - 30/1/12 at 02:32 PM

Cheers for all the advice, here's what I found!
Description
Description
New engine arrives shortly!

Cheers
Chris

James - 30/1/12 at 04:08 PM

quote:
Originally posted by ChrisL
Cheers for all the advice, here's what I found!
Description
Description
New engine arrives shortly!

Cheers
Chris


wow!

thanks for the update- interesting to see the conclusion.

So the bore was full of fuel then?

Make sure you find the cause before you put it back together with your new engine... don't want to do the same!

Best of luck with it!

James

ChrisL - 31/1/12 at 09:31 AM

No the bore had drained, prior to taking the engine apart the inlet manifold was full of fuel. Tried to purge it by taking the spark plugs out and turning over, but by then the damage had already been done.
I've put a motorcycle fuel pump on, from the same bike as the carbs, and adjusted the float heights, when I start putting it all back together I'll test the fuel pressure at the regulator. Next thing will be a rolling road setup. I'll just have to keep an eye on it and check the inlets are clear before starting in the mornings...

hubby - 4/2/12 at 10:47 PM

sorry to here that chris
are you getting the 2.0l black top??

ChrisL - 5/2/12 at 03:28 PM

Hi Hubby,

Yes I am, still lots of things to do, just need some free weekends!
Are thinking of doing the same?