Blown head gasket?

[Richard123]

Personally, I think you've eliminated head gasket failure with your compression test.  Strong fuel smell and how you re-started the car with the tow truck operator would indicate flooding (with fuel).  

 

I think our fuel pressure regulators are typical and sense vacuum above the diaphragm.  If the diaphragm fails, you get raw fuel flooding the intake and stalling out the car.  Remove the vacuum line and turn the key to start the fuel pump.  See if gasoline pours out.  (OF course route it to a container for safety!).  That'd be the next 2 minute test I'd perform.

 

Good luck, hope it turns out to be a minor problem!

[Corban]

Back home again after a two day trip. I'll test the fuel pressure regulator as Richard suggest. Quick and easy.
I'll post results in a few minutes.

[Corban]

Richard!!! Brilliant!!!

I disconnected the small hose that comes from the inlet manifold (guess it is the one that should increase fuel pressure when boost rises) and cranked the engine.

Had a small cointainer in place and yes, there was lots of fuel coming out! If I understand the design of the FPR-valve correct, that side of the diaphragm should be dry when all is OK.
Fuel should only be on the other side, trying to reach the return line and only compressed air (boost) on that side to increase pressure on return valve.

So fuel hitting exhaust manifold is unburnt fuel that escapes via the leaking manifold gasket for cyl #4. If this is the only fault, THAT'S GREAT NEWS!
No lump out, no head off 

Then comes the next question, where do I get a new FPR-valve?

[swindon_alan]

Part no. A910E6950S - Fuel Pressure Regulating Valve

Used on the Excel as well.

South West Lotus:

[Esprit/Excel] Pressure Regulator Product no.: A910E6950S Pressure Regulator. Engine Turbo 2.2 4 cylinder. This part is now obsolete.

£75.00 *   In stock

http://www.thelotuscentreonline.co.uk/Excel/Engine

S J Sportscars:

http://www.sjsportscars.co.uk

FUEL PRESSURE REGULATOR (All 4 cylinder models with Delco)

A910E6950S

EACH

59.50

[Corban]

Thanks Alan, couldn't find it at SJ first but when I typed the partsno. it showed up at £59.50, cheapest so far.

"Add to basket" I guess. I have also been thinking about Travis experience with bad header caps that can't take the pressure they are supposed to thus bringing coolant to a boil
at lower temps, sending coolant out the rear left wheel arch. My boot floor was wet in left rear corner when I had the incident and I've had some dripping in that region even after normal driving lately.
This might explain my coolant loss. Think I'll get new ones of them too.

[swindon_alan]

Don't forget SJ is always plus shipping plus VAT @ 20%...

[Chillidoggy]

On 9 May 2016 at 15:26, ian29gte said:

/\ This.

And it's also entirely possible to have sprung a leak from a fitting or pipe connection on the main fuel rail, maybe an injector, maybe the PRV, which would then tend to track around the back of the cylinder head between the head and the turbo heatshield, and drip down onto the exhaust manifold. Couple that with the cam tower oil leak that Sparky's mentioned from whichever bit of the cam tower you choose, and there you go.

Loss of fuel pressure causing engine to run rough, oil and fuel leak causing the rest.

And it's AC Delco P/N 217381.

Pleased you haven't had to take the head off! 

 

 

 

 

[Corban]

Absolutely on the right track Ian. Fuel found its way via the small hose from PRV to inlet manifold. Nothing wet or visible on the outside.

[Richard123]

Excellent news, now you just have to figure where the oil came from.  

I'd guess it's a separate problem, but if that exhaust gasket is burnt through, you'll hear it pretty good and clear on start-up!      

 

[Vulcan Grey]

Good news, that is a much easier fix!

[Vanya]

Told you it was gonna be simple! Just be happy your car didnt catch fire. I know a guy who had a similar accident and wasnt so lucky...

[Corban]

You were absolutely right Vanya. When you concider how hot that exhaust manifold gets, it's a miracle that the unburnt fuel didn't burst into flames right away.

When it comes to my SE I'am the "hope for the best, prepare for the worst" kinda guy. Now a broken diaphragm was good news 
 

[Richard123]

8 hours ago, Corban said:

You were absolutely right Vanya. When you concider how hot that exhaust manifold gets, it's a miracle that the unburnt fuel didn't burst into flames right away.

When it comes to my SE I'am the "hope for the best, prepare for the worst" kinda guy. Now a broken diaphragm was good news 
 

Thinking about scenarios where the two problems are related.....perhaps you should check the consistency of the oil, likely change it.

 

You spilled a bunch of oil on the ground and on the manifold, yet oil level is fine.  That doesn't make sense.  What if as the BPR filled the intake with fuel, some made it to the crankcase, thinned the oil out, caused minor leaks that you weren't monitoring to become substantial, and the fuel restored the level on the dipstick?  Does the BPR vacuum line feed direct to the manifold?  Memory is fading with old age, but might it tee into a crankcase ventilation line giving it a direct route to the crankcase?   

 

I'd be all over the oil.  Make sure it isn't a solvent at this point.

[Corban]

Good point Richard, I think there is a "T-piece" that connects the hose from inlet manifold to the non return valve (green thingy) serving the crankcase ventilation.
It is possible that some fuel has entered that way. Needs checking out before I start her up. 

[Chillidoggy]

As Richard said, it doesn't make sense.

My take on it:- I think P/N 44 is a non-return valve which prevents flow towards P/N 47, the 'green thingy' which is the crankcase breather. The latter is not a non-return valve, it just has a stack of stainless gauze inside it. If I'm right, then it's not possible, or highly unlikely, that fuel could pass into your sump that way. My guess is that the fuel leaking from the PRV did a good job of carrying with it dirt and oily residue from various old weeps before it hit the manifold, and the ground. That's what you saw.

Check Lotus Service Notes EMH2, page 22 for details on the crankcase breather system.

 

Edit: It is possible fuel could have passed into a cylinder and leaked down past the rings. Might be worth an oil change, oil is cheaper than an engine.

[Corban]

Ian, thanks, I typed before I posted the picture, even before checking parts in the list on the next page. Number 44 is of course the non return valve and 47 is to catch oil droplets/mist I guess.
I too think the fuel escaping via the exhaust manifold gasket has worked as a solvent on old deposits in that region, taking oil with it to the ground and the manifold.
Since the car is up on stands, I crawled under yesterday and I could tighten the nuts quite a bit for the exhaust manifold for cyl #4. I find this strange since the metal flaps were bent to prevent the nuts coming loose.
Sloppy job by PO?

[Sparky]

Depends what you mean by 'quite a bit'.  The nut torque is very low by design.  Also, the studs are known to migrate out!

[Corban]

I could easily turn them 3/4 to 1 full turn before they started to feel tight. I think this can explain the leaking gasket.

[Vanya]

Strange. Were the lock tabs in contact against at least two nut flanks? 

You could also try and replace the nuts with high temp Kaylocks. I have one on my turbo to manifold as an experiment and it's holding real tight. Expensive bastard it was though. 

I've previously seen fluid in the tube labelled P/N 40, might have lost some fuel that way!

Have you tried starting it up with the rail and associated hoses clear of the engine with a container underneath?

Too bad you live so far away I'd really like to see this for myself. 

Edit: Henrik, feel free to give me a call if you wanna throw ideas around!

[Corban]

Not only a little fuel in P/N 40... When diaphragm ruptures the full pressure of the fuel in the rail finds its way to the "dry" side of the diaphragm and goes via hose P/N40 to "T-piece" P/N 41 and further on to flood the intake manifold to which P/N 41 is attached. You literally take the total capacity of the fuel pump and connect it directly to the intake manifold. No wonder there was a smell of petrol and the engine stalling, talk about a rich mixture! Didn't dare start it up, fuel was spraying all over with the hose disconnected. With the hose connected I already tried when the tow man picked me up.
New FPRV ordered together with header tank caps.

I've tightened the nuts on exhaust manifold and folded the metal flaps real tight (which they weren't). I'll keep an eye on them to see if they come loose again.

I don't have the service notes for the delco, but the principle is the same as in the pic below. As can be seen a ruptured diaphragm will close return line and direct fuel to the boost pressure connection from plenum.

[Corban]

Update!

Installed the new fuel pressure regulating valve that arrived yesterday.

She started immediately! No fuel leaks, only a slight smell of oil burning off of the exhaust manifold but that I think is residue.

To be safe, I will make an oil and filter change before I take her for a longer drive. Slight risk of fuel in the oil and better safe than sorry.

Thank you all for your input and helping me find (and solve) this problem