Codes 13, 23, 31 and 32. Replaced sensors, same codes, help!

[Nosferatu]

Hi,

My 91 Subaru Liberty non-turbo(australian version legacy) throws 13, 23, 31 and 32 codes.

Cam angle sensor was replaced with a second hand good one, throttle position sensor connector cleaned and inspected, MAF sensor was replaced with a good second hand and O2 sensor was replaced with a brand new sensor - still same codes!

Checked and cleaned every earth ground in the engine bay, reset the codes, and it still throws the same codes as soon as it goes into self test mode (green connector).

The car starts and runs quite normal in idle. It is a little hesitant in the 2200 - 2500rpm, and then goes back to normal. Also the exhaust smells of unburnt fuel with a little of grey/blackish smoke coming out. Fuel economy is down to 300-320kms per tank which is ridiculously more than the nice 400-450kms I got previously.

It did have an issue with the harmonic balancer getting loose (because the idiot who removed it last did not put thread locker on it), the result was a near-snapped crank pin. Could not afford to change the crankshaft so I re-aligned the crank pulley with the pin position and put small welds on the pulley to hold it in place. Then machined the harmonic balancer (about 3mm on the inside bure that faces the crank pulley) to fit over the welds. The engine started running wierd when the crank pulley was loose but ran good after the fix. The fix was done over 2 years ago and it only started throwing the codes recently, so I doubt that it would have had an impact on the electrical, but anything is possible i guess.

Can anyone please advise what can be the problem?

[kimokalihi]

I wouldn't use thread lock either. Its hard enough to remove without it. Torquing to 130 ft lbs should be adequate.

What are those codes for? If you get a problem with the cam or crank sensor it can throw several codes. I had a broken wire right at the connector for my cam sensor and I had several codes and just happened tp notice the bad wire because I had been working near the connector so I checked everything there. Check all your connectors for broken wires going into the connectors because the wiring is old and gets brittle. It could also be a timing belt skipped a tooth or two?

[Nosferatu]

Thanks for the quick reply. I have obtained a second hand ECU, have swapped it over with the old one - now it doesn't flash the codes anymore, but the car is still very hesitant especially under load (going up-hill the engine starts backfiring and behaving very weird).

I have swapped the ignitors with a some that I have had laying around, leads are new (4 months/12000kms) old. Havn't checked the sparks yet, but they are only about 20,000kms old - so it shouldn't be a problem. The coil pack is fairly old, might look into getting a new one. Also I will check the wiring tomorrow and post back the findings.

Meanwhile, any suggestions or advice will be very appreciated!

[wtdash]

For those wondering:

13 - Cam sensor
23 - MAF
31 - TPS
32 - O2 (oxygen) sensor

See POST below.

GL,
Td

[Legacy777]

Welcome to the BBS.

He said he tried another MAF sensor.

I would suggest trying to replace the coolant temp sensor. They don't usually throw codes when they go bad, but can have drastic affects on how the car runs, since it affects the air-fuel ratio. In the states, they're only about $20 USD, so that may be an inexpensive option to try.

[Nosferatu]

Hey all,

I know it has been a while, I have been running around trying the temp sensor, re-earthing the car (got 1 on the inlet manifold, one on the starter top bolt [the one that bolts through the bell housing into the block], one on each rail and one where the stock is beside the engine fuse box), unplugged every connector at the engine bay examined the wiring and cleaned it with electrical contact cleaner, tested all the ECU connections as per the manual (checking power and earth). Out of frustration I have taken the timing cover off, removed the belt (again) and checked every mark, counted the teeth to each cam shaft mark, put it all back - same deal. Got a timing gun - timing is 6 degrees advanced at idle (which is apparently normal for this engine).

I have also noticed little bubbles coming out of the coolant (no water in oil or oil in water, no excessive moisture in the cylinders, spark plugs are not fouled), did a head check (the blues liquid thing) - apparently the head gasket is ok - but I don't trust it - the bubbles are coming from somewhere! I think there is a micro crack that lets compression out in the head which can cause high fuel consumption.

Then the alternator died..... Which could have been contributing to my problems by producing excessive engine load which will affect the fuel consumption and can throw everything out of whack because of .5 lower voltage.

All in all I got sick of it lol. I ripped out another engine for $280 (only 198,000K / 123,030 miles) from a wrecker - complete with all sensors and everything. Ordered a gasket kit and new piston rings. Going to machine the heads flat, re-grind the vale seats, assemble and keep driving till it dies. Then get the RS/GT loom and convert to 2004 STi (Jap front cut).


Thanks for the help everybody!

[Legacy777]

I'd suggest getting the block resurfaced as well to mate with the freshly machined heads.

[Nosferatu]

I'd suggest getting the block resurfaced as well to mate with the freshly machined heads.

Thanks, I will invest in a block re-surface too then.

[Legacy777]

It may not need much, but I learned the hard way that it's best to do so the new headgasket gets a good level mating surface.