1994 3.1L strong exhaust smell, high fuel consumption

[dw_bobby]

Hi All,

For months now i have been experiencing very high fuel consumption (35% higher) and very strong (non-visible) exhaust odour. Car running fine other than that.

New plugs, new O2 sensor, spark cables and knock sensor (non-OEM) have 2 yrs on them.

No change after the plugs and O2 sensor have been replaced, and i'm pretty much desperate and broke by now.

Does any one have any ideas?

Could this be a faulty fuel injector (or more)? What can i do??

Thank you.

[tblake]

It could be a leaky fuel injector, or possibly a leaky fuel pressure regulator.

Is this the 3100sfi motor, or 3.1mpfi?

If the 3100, you can pull the vacuum line off the fpr, turn the key to on and check for fuel coming out of the vacuum port on the fpr.

If it is the 3.1, I'm pretty sure the fpr is under the intake plenum and cannot be accessed without removing the plenum.

Either way, I would suggest to rent a fuel pressure guage and check fuel pressure. Most places like autozone or advance will let you rent the fuel pressure regulator for free.

[dw_bobby]

thanks for the answer!!

it's the SFI.

What does it mean if when i pull the vacuum line fuel comes out?

[tblake]

The fuel pressure regulator internal diaphram has ruptured allowing raw fuel to be sucked into the vacuum line, and the FPF needs to be replaced.

I think there is just enough room on there to get the old one off without removing the intake plenum. Just be carefull, I think there are a couple o-rings in there. Don't lose then, and a light coating of engine oil will make it go back together easier without ripping them in half.

[dw_bobby]

Thanks t.

FPR was fine, fuel pressure is fine.

Unfortunately chemical analysis of the water not so fine.

Smell is apparently water, which means car is going bye bye

[tblake]

You don't want to throw a set of head gaskets in it? The 3100sfi is a rather easy motor to work on. We can help you! I have been inside about 10 of them and counting in my day.

[dw_bobby]

i really appreciate your taking the time to answer me, means a lot.

I'm actually worried that it's not only the gaskets, if the heads will need resurfacing it will not be worth it. There is really no way of knowing, is it?

Car water temp is fine, never overheated.

Do you thing changing only the gaskets will do any good?

[tblake]

How many miles are on your car?

If the motor was not over heated, you should be fine, but if it were me, I'd bring it to the heads to a shop and have them checked out at the very least. It usually doesn't cost much.

[dw_bobby]

car has 167000 miles on it. only major job i did to it was changing the valve covers (to the 3.4 aluminium vs the plastic ones) and the intake manifold gasket.

i parked it until i figure things out. i'm driving a greenish hyundai getz in the mean time...