94 FWD with CEL code 23, won't idle but runs at 3k RPM
 

Hi all,

I bought a 94 FWD LS (Pearl White) a month ago. It's at the garage while I'm working 3,000 miles from home.

The previous owner was getting a code 23 (MAF) and it wouldn't run properly at times. Then he got a code 11 and couldn't afford a repair, so he sold it. I got a nice deal on the car, but now I need to get it running and the garage has been troubled as to where to begin.

The radiator was cracked in a minor collision before previous owner decided to sell it (the final straw), so it has a non-functioning radiator right now.

The symptoms:

1. MAF connector was replaced by someone (previous owner had it about 6 months, unaware of this "mod").
2. Connector has 4 wires running into it, first conductor out of the 5 on the MAF is not attached. Is this a problem?
3. 4 MAF wires were stripped and twisted to the matching one, but then ALL wires were shorted together and electrical taped (previous owner unaware of this).
4. Above corrected, still throwing code 23 after each reset.
5. Car will start right up but won't idle and stalls out. I had it running *once* for about 8 minutes at 35 degrees Fahrenheit or so without applying throttle manually. It ran nicely until the engine warmed up and then the idle began to drop and the lower it dropped, the more the engine began to surge and tried to keep running. As the idle speed got lower though, it struggled more and more until eventually I shut it off.
6. If throttle is applied, it will happily run at 3k RPM, anything lower than that and it will surge trying to keep itself happy.

So.. The garage suspects a vacuum leak possibly, or broken wiring between MAF and ECU. But it should function in limp mode and it's not. I suggested they check solder joints on MAF and I have a replacement MAF pulled from a junkyard late 90's 2.5L Outback they can try as well. My other car is a 99 Outback, so I have the MAF as a spare. Will the Outback MAF work in the car? They look the same, but the numbers on them are different.

I pulled the alternator and used electrical contact cleaner on the 2 sensors beneath it and the garage hasn't mentioned anything about Code 11. The sensors were clean when I saw them, so it may have been a fluke?

Does any of this make sense?

For replacement radiators, I found these on eBay. I see the Silla 7420A is $153 and $296, for the same unit. Is this the best one? A local mechanic guy where I'm working (in Las Vegas) said if I get a plastic top/bottom radiator, it'll only last a few years. I'll normally have this car in western Massachusetts so I don't think it'll be so short-lived?

Does anyone have any ideas what could be wrong here? Where should the garage check first? They were going to have a guy come in to check continuity on the MAF wiring to the ECU over the weekend, but I'd like to have more ideas for them if possible. Is this common at all?

Thanks!
Eric

Re: 94 FWD with CEL code 23, won't idle but runs at 3k RPM
 

Code 11 is for the crank sensor and will prevent it from even starting in most cases. Pull the sensor and look for dirt or debris that could affect the magnetic field of the sensor.
You may need to replace it as they do fail over time. The rule with Subarus is to fix the lowest number code first. Also, having a bad MAF sensor could also cause the car to start and immediatelly stall.

The Outback MAF will work just fine. Seems like you may actually want to sort that out first as it doesn't seem like a crank sensor problem. It may have been a code it threw once when it died. Try clearing the codes and rechecking once you try the "new" MAF sensor. You're likely going to have to sort out that wiring first.
Also, with the MAF unplugged or a significant problem with it, the car will not stay running on its own.

Re: 94 FWD with CEL code 23, won't idle but runs at 3k RPM
 

Thanks for the info, Nate. I added one line to my post a few mins after posting, maybe you replied before I got that in there. I had cleaned both sensors below the alternator, which were already nice looking, no gunk of any sort on them. Since it only gave that code once, I think it was just a random thing.

Does the 94 have a limp mode or is that only OBD2 based Subarus?

I'll try to have someone bring the other MAF to the garage this week for them to try out. Should there be 4 or 5 wires going into the MAF harness? The connector that's on there has the first hole plugged (looking at it from the back end of it, from the left side of the car).

Thanks,
Eric

Re: 94 FWD with CEL code 23, won't idle but runs at 3k RPM
 

OBD1 definitely don't have any type of limp mode. With a MAF sensor problem or disconnected, you have to hold your foot on the gas to keep it running.

Also, there are radiators on ebay as low as $130 or so. People have had relatively good success, a few early failures but with a lifetime warranty, you can't go wrong IMO.

Re: 94 FWD with CEL code 23, won't idle but runs at 3k RPM
 

Okay, I suspected a lack of limp mode as a possibility. It runs *great* with the gas on. 3k RPM and up it sounds really nice. Except I've never driven this car. :rolleyes:

Is the Silla model a good deal for $153? The only reference I have is other people selling it for double that in the same place. I don't want to go crazy, but if I can get a "$300 radiator" for an extra $20 or $30 over "a cheap one" (whatever that means), maybe it's worth it? :confused::lol:

Eric

Re: 94 FWD with CEL code 23, won't idle but runs at 3k RPM
 

I've had the Silla radiator for a few years now. It has not given me any trouble.

Re: 94 FWD with CEL code 23, won't idle but runs at 3k RPM
 

Thanks Sean! I think I'll go with the Silla one, it seems somehow like it's a better deal. At least it has a big logo on it, which implies performance.. :D

I'll get the Outback MAF to the garage and see how that goes.

Is it possible there's a vacuum leak? They felt it could be a leak, because vacuum pressure is much lower at higher RPMs.

Would it be worthwhile to get a hose kit while the garage has it and the radiator will be removed? This one came up as fitting my car, but I don't know about the quality, etc. I'm thinking red would look better under the hood than blue too, but just an idea.

I've had my Outback for 13 1/2 years and never really felt inclined to do anything to it, but now that I have this car, I want to make it as good as I can, inexpensively if possible. :)

Eric

It's running!
 

Good news, the garage got it running. They used the spare Outback MAF and continuity checked the MAF wiring to the ECU (which was all working). The throttle body needed to be cleaned a bit but it's running really nicely now!

I went with this radiator:
http://www.ebay.com/itm/230887012198...84.m1439.l2649

It's not mentioned, but it's the same Silla that others are selling for up to $300 on eBay. I talked to a salesperson on the phone there and asked what the make and model was and he looked it up and it's the same model, so I suggested they listed that in the auction. The shipping was free and no tax was charged and it was received overnight in Massachusetts, all the way from Florida, for free! :D

So now to replace the hood and bumper and headlights and corner markers and figure out why the ABS light is on. Garage suggested it might be a speed sensor. The ABS computer was sitting in about an inch of ice when I wanted to check the lights on it. It's thawed out now and the garage will check it all out. Then to register and insure it and drive my new car for the first time! :D

-Eric