p1800e petrol in oil sump?!

[jackknowlden]

i took my car into the garage to have any repairs it needed done to get it through its MOT, all went smoothly to my suprise until i went to collect it...
drove it out of the car park and it was running like a dog, juddering and cutting out unless i held my foot slightly on the accelerator, i drove it straight back in and upon inspection it seems that 20 quids worth of fresh petrol has gone straight through into the oil sump.

any ideas on reasons that would cause this?

ive drained the oil(full of petrol aswell), put fresh oil in again, it started up and ran like a dream but checked oil and more fuel has gone in so the fault is still occuring.

any answers from you guys greatly welcome!!

[lancsclassics]

Does the engine have a mechanical fuel lift pump?. Could be ruptured, passing fuel through to sump?

[jackknowlden]

not 100% to be honest, a guy i know has mentioned that same diagnosis but when i mentioned it to the garage he seemed to palm it off and said it wasnt that. its a 1971 1800e and i think it does have one yes.

basically trying everything before i have to rather than looking at a full rebuild before the summer!

[lancsclassics]

Should be easy to check out the pump. Unbolt the pump from the block with the pipes still on, operate the pump lever by hand and see if fuel leaks out from the back. You should be able to see if fuel leaks through to the crankcase side.
Cheers, Mick

[jackknowlden]

i'll call the garage working on it and mention it, they must think im a pest by now telling them how to do there job haha!

thanks!
jack

[capt jack]

Are you sure it's petrol and not coolant?

It's an 1800E, so if it's as standard then it has the D-Jet fuel injection system and therefore an electric fuel pump, which is located on the rear chassis cross member.

There should be a filter, the pump, a fuel line to the engine, the fuel rail along the top of the engine, a pressure regulator and then a fuel return line back to the tank.

Petrol is introduced into the combustion chambers via the four fuel injectors, one for each cylinder. It's hard to see how 4 gallons of petrol could squirt themselves through the injectors, into the cylinders, past the piston rings and/or valves, through the oil-ways and into the sump in the time it takes to drive it out of the garage car park.

You say that the car has had some work done? I reckon the more likely explanation is that as the car has been put back together, someone has connected up some pipework wrong and the fuel system is cheerfully dumping petrol into the sump.

If original the car will have either a 'rounded oblong' fuel rail with the pressure regulator positioned on one long leg of the oblong, or it will have a single rail with the regulator at one end. In either case make sure that the inlet and outlet pipes to and from the rail go either to an injector, or to the regulator, or to the fuel tank. If they go anywhere else then this is very wrong!

That the engine will run suggests to me that fuel is being delivered to the fuel rail and regulator OK, but that unused fuel is not being returned to the tank. The system works by keeping a constant flow of fuel under pressure (2 bar) in a continuous circuit tank-to-pump-to filter-to engine and back to the tank. Enough fuel is squirted via the injectors to run the engine, and unused fuel is sent around the circuit again. Certainly, without being restricted by the small size of the injectors, the pressure from the fuel pump and the realtively large bore of the fuel lines would be enough to deliver serious amounts of petrol in a very short time.

Clearly this fault is highly dangerous, and I wouldn't drive the car until this has been sorted.

Jack

[b20e]

Hi
I have fuel injected P1800E and ES and I think Jack's answer is very plausible.

There are 5 places where the petrol can get into the engine in the volumes you describe - the 4 fuel injectors and the cold start valve.
The fuel is fed into the rail to feed the injectors and the cold start valve mounted on the top of the aluminium plenum where the air intake and throttle valve are.

The only thing else I can think is if the manifold pressure sensor is broken then it could be drowning the engine in petrol. I have had this problem and the worst it did was use huge amounts of fuel and make the exhaust glow cherry red in broad daylight. But not fuel in the oil.

[jackknowlden]

problem hopefully solved!!

i mentioned practically every fault everyones mentioned and had a few sleepless nights thinking of how much the bill was going to be but had a call from the garage.

one of the spark plugs wasnt sparking and apparantly causing the non ignighted fuel to flow down to the oil, no idea how but changed the plugs, new oil and filter fresh fuel and after driving 5-10 miles havent had a cough or slutter and a dip of the oil has no petrol smell so touch wood problem solved!!

thanks for the help guys!