Engine power loss?

silver123103 · Post by **silver123103** » Thu Aug 19, 2010 6:35 pm

Hey guys i was driving on a highway the other day, slightly up hill and my '94 liberty seemed to lose its power. It felt like it was running on 3 cylinders and didn't sound healthy. I pulled over for 10 minutes and then it went fine for the rest of the way home (about 30 minutes).

Any ideas what could have gone wrong?? its done it several times before but this is the first time it has done it in like a month or so

YouTube · Post by **El_Freddo** » Thu Aug 19, 2010 7:00 pm

I had that with my EJ22 in the L. I think its the throttle position sensor or the air idle control valve. I'm not sure exactly what it is as I've got a list of sensors as long as my arm that are not working properly now. She's a bitch to start when cold which is a real problem when you live in the snow!

Have a go at checking the codes - you'll have to located the two black connectors under the dash, I'm not sure where these are exactly on a liberty. You need to connect these two plugs then turn the ignition to the ON position WITHOUT the engine running. Watch the check engine light for the codes. Long flashes =10, short flashes =1. It will flash long then short, if or when it flashes another long it is the start of a new code or it has looped back to the start. You can write these down like morse code then "translate" them after.

There's a good thread [url=http://www.ausubaru.com.au/showthread.php?t=14372here[/url] about the codes and their meanings.

Cheers

Bennie

RSR 555 · Post by **RSR 555** » Thu Aug 19, 2010 7:02 pm

Could be many things but I'd look at the fuel system and make sure the filters are clean and the pump pressure is good. Also check that the tank is breathing correctly. Another thing to check is the engine temp.. make sure it's not getting too hot.. never trust the gauge, always listen out for boiling water as the temp sender only works correctly when there is water on it.

These are just some things that change after resting the car for a short while.

silver123103 · Post by **silver123103** » Thu Aug 19, 2010 9:11 pm

i checked to see if it had any error codes but it didn't..

it doesn't sound like any water is boiling or anything like that

its got a new fuel filter on it and im not sure how to check pump pressure or anything about the tank breathing correctly

silver123103 · Post by **silver123103** » Fri Aug 20, 2010 3:31 pm

I just did a check on it and it came up with trouble codes:
33- vehicle speed sensor 2
51-inhibitor switch
52- parking switch

RSR 555 · Post by **RSR 555** » Fri Aug 20, 2010 4:09 pm

Auto trans hey.. I'd look at getting the gearbox serviced (filter cleaned) and new fluid and while they have the pan off, make sure all the wires are good inside.

Also check (maybe first) that the selector shifter switch on the transmission is connected correctly and/or not have water on the connection.

silver123103 · Post by **silver123103** » Fri Aug 20, 2010 4:15 pm

it recently had a transmission service, they didn't find anything wrong with it..
Where is the vehicle speed sensor 2?

maybe its stuffed

RSR 555 · Post by **RSR 555** » Fri Aug 20, 2010 4:35 pm

I can't remember if the one in the gearbox is #2 or the one in the dash cluster.. the FSM should be able to clarify that for you. My best guess is the one in the box as they have a tendency to fail.

silver123103 · Post by **silver123103** » Fri Aug 20, 2010 7:04 pm

Are they expensive to replace?

YouTube · Post by **El_Freddo** » Fri Aug 20, 2010 7:21 pm

silver123103 wrote:Are they expensive to replace?

Probably - that's my definitive answer!

Cheers

Bennie