Hi there everyone,

I got a strange sort of prob with my Liberty(Legacy) and I am running out of things to do to try and resolve it, it doesnt seem to like being driven with the tacho above about 3100rpm,or under any sort of load, stay under that and it runs fine, if I go over that it starts to cut out, the best thing I can think of to describe it is it feels like it is running out of fuel, it gradually loses all power and goes into a pinging frenzy until it stops,I pull over, turn it off and then a quick restart and it is fine, away I go again, it doesnt do it straight away though, from a standing start and taking it to 6000rpm through the gears it will start playing up and cut out when I get to third gear, another example, if I am on the highway and encouter a decent long hill and have to shift back to forth it will die before I make it to the top, back a gear and over taking causes the same result. Working on the senario that it seemed like a fuel supply problem this is the things I have changed so far with no improvement.

Fuel filter

Fuel pump

Drained fuel tank

Changed ECU

New plugs

New Leads

Upper cylinder cleaner

Air filter

I am now wondering if it could be some sort of ignition problem, maybe the ignition cant handle any sort of load, or is it possible that dirty injectors could cause this? It is no fun at all buying all these things just to have the problem persist

Any help or advice much apprecitated

Thanks in advance.

Subaman

Dunno with the pinging but everyhting else sounds like a clogged cat.

 

can you give more details/history on the car?

Oh dear, sounds like an expensive hunt!

 

 

Sticking with the fuel system, there is a pressure regulator on the rear end of one of the banks of injectors, your passenger side I believe. Maybe it's returning fuel to the tank prematurely, and therefore starving your engine at higher revs. A very lean mixture into a hot engine might pre-ignite and be the source of the pinging.

 

The cat thing mentioned by Texan is also worth a look. If the exhaust can't escape fast enough, there will be a build up around the O2 sensor and the ECU will turn the mixture lean because there is no oxygen upstream of the cat, as there should be.

 

Knock and O2 sensors should also be looked at.

 

Best of luck!

Thanks guys,

Very helpful infomation, I will look into the blocked cat idea and also the regulator. The car is 91 GX Liberty,AWD manual with 250,000 km on the clock.

Cheers

Subaman

Well the problem might be solved, switched the fuel reg today for a reg off one of Bretts(AUSubaru) turbo manifolds he had laying around and so far so good, I will give it a few more days before I get too excited though. Thanks again for the advice and I will keep you posted on the outcome.

Cheers

Subaman

Can you rev the engine above 3100 rpm in neutral?

Yes, can rev it all the way to the rev limiter in nuetral.

Only 250k km? Car's nearly brand new, mate!

 

Mine has 306 on it, and still loves to rev

Originally posted by Legacy777

Can you rev the engine above 3100 rpm in neutral?

 

I'm pretty sure the reason Legacy777 asked this is because he thinks maybe your MAF sensor is on the fritz. If the sensor was determined to no longer function correctly, it would put the ECU into a "safe mode" in which it will only allow the car to go to about 3000rpm so you can get home...

 

While you claim that's not one of your problems, it might be worth taking your MAF sensor off and possibly testing it with a multimeter to assure it's operating properly. They can get real finicky sometimes and otherwise operate normally.

Originally posted by subyluvr2212

I'm pretty sure the reason Legacy777 asked this is because he thinks maybe your MAF sensor is on the fritz. If the sensor was determined to no longer function correctly, it would put the ECU into a "safe mode" in which it will only allow the car to go to about 3000rpm so you can get home...

 

While you claim that's not one of your problems, it might be worth taking your MAF sensor off and possibly testing it with a multimeter to assure it's operating properly. They can get real finicky sometimes and otherwise operate normally.

 

yeah you nailed what I was wondering.....it'd be worth looking at it....however his problems sound a little different...