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Incorrect TB installation?

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  • Author

I think I'll unplug the fuel pump and try to start it (after the football game) and see if it makes any difference? I imagine the oil dipstick smell's strongly of fuel these days?  Sure hope I didn't bend any rods when the cylinders were half full of gas while I kept cranking it over. I know it was jamming up every revolution or so (until I'd put the gas pedal in flood clear position while cranking) then it would almost try and start.

Edited by darsdoug

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  • http://www.troublecodes.net/subaru/   Find anothe MAF to test with. That's probably the problem. Or unplug it and the computer should go into limp mode.

I really think you ought to start with the MAF. If the computer doesn't know how much air is coming into the engine, or is getting an incorrect value, it won't know how much fuel to add. Here is the info from Mitchel on Code 49:

 

Code 49 indicates use of an improper airflow sensor. Symptoms include the following:

 

Rough or erratic idle.

Failure of engine to start.

 

If a code 49 is displayed, check specifications of airflow sensor and ECU. Replace the airflow sensor or ECU with the correct type as follows:

 

Automatic Transmission - Hot film type airflow sensor (JECS).

Manual Transmission - Hot wire type airflow sensor (Hitachi).

  • Author

I really think you ought to start with the MAF. If the computer doesn't know how much air is coming into the engine, or is getting an incorrect value, it won't know how much fuel to add. Here is the info from Mitchel on Code 49: Code 49 indicates use of an improper airflow sensor. Symptoms include the following: Rough or erratic idle. Failure of engine to start. If a code 49 is displayed, check specifications of airflow sensor and ECU. Replace the airflow sensor or ECU with the correct type as follows: Automatic Transmission - Hot film type airflow sensor (JECS). Manual Transmission - Hot wire type airflow sensor (Hitachi).

o.k. I shall pursue that before getting into the possible injector problem.

  • Author

It does indeed have a Hitachi MAF. I removed it and examined the hot wires. They appear clean and intact.

  • Author

I don't know much about injectors. This should be an adventure.

Edited by darsdoug

  • Author

Did some reading and learned that it's normal for both injector wires to appear hot if grounded to the chassis with a test light. The injectors are in fact grounded by the ECU thus completing the circuit and pulsing the injector as needed. So if all four injectors are stuck open "electronically" would that be a bad ECU?

Only if theyre constantly grounded.

When you have voltage on both sides it's because there is no ground.

When grounded the voltage on the ground side of the circuit drops off.

Edited by Fairtax4me

It does indeed have a Hitachi MAF. I removed it and examined the hot wires. They appear clean and intact.

 

This is now how you test a MAF and it does not mean it's functioning correctly.  

 

"

A faulty air flow sensor will set code 23 in the on-board diagnostic system. Refer to the schematic diagram and test the sensor with the diagnostic chart. If an air flow sensor that is incorrect for the vehicle model is installed, code 49 will set (whether the sensor itself is faulty or not). Automatic transmission models use a hot film type air flow sensor and manual transmission models use a hot wire type. These are not interchangeable.

 

Wire color code identification:

 

L: Blue

B: Black

Y: Yellow

G: Green

R: Red

W: White

Br: Brown

Lg: Light green

Gr: Gray

 

 

 

AIR FLOW SENSOR DIAGNOSTIC CHART

 

 

CHECK ECU VOLTAGE

 

1. With ignition "ON," measure voltage across ECU connector terminals and ground as follows:

 

Connector & terminal:Voltage:

(B48)8-Ground 10-13V (engine "OFF")

13-14V (engine at idle)

(B48)9-Ground 0-0.3V (engine "OFF")

0.8--1.2V (engine at idle)

(B48)10-Ground 0V (engine "OFF")

0V (engine at idle)

 

CHECK ECU HARNESS AND RESISTANCE

 

1. Disconnect ECU and air flow sensor connectors.

2. Measure resistance between ECU and air flow sensor connectors as follows:

 

Connector & terminal:Resistance:

(B48)8-(B1)1 0 Ohm

(B48)9-(B1)4 0 Ohm

(B48)10-(B1)2 0 Ohm

 

3. Measure resistance between air flow sensor connector and ground:

 

Connector & terminal:Resistance:

(B1)1-Ground 1M Ohms min.

(B1)4-Ground 1M Ohms min.

(B1)2-Ground 1M Ohms min.

(B1)3-Ground 0 Ohm"

imagesWLinks_zpsvka1a9yz.jpg

 

How it works:

"PURPOSE

The air flow sensor measures all air entering the engine through the intake system. This information is vital to the ECU to determine proper fuel mixture and ignition control configurations.

LOCATION
The sensor is mounted to the air cleaner box in front of the right strut tower.

CONSTRUCTION
A hot-film sensing head is used to measure air flow. Air flow is measured by determining the cooling effect on the sensing head.

OPERATION
Whenever the ignition is ON, the sensor produces an output signal to the ECU. The hot-film sensing head acts as a temperature sensitive resistor. The ECU maintains the sensing head at a preset constant temperature. As air passes over the hot-film, it has a tendency to cool. Since the sensor head changes resistance based on temperature, a varying current is required to maintain constant temperature. The internal circuitry of the sensor monitors this changing current demand and sends a varying voltage output signal to the ECU, tracking current required."

Edited by lstevens76

Oh, and to add you are actually getting 2 codes for the MAF.  23 and 49 are both related to the MAF.  If that MAF is reporting that it's getting a ton of air the ECU is going to dump fuel.

 

On top of that you have a knock sensor code which will cause the ECU to adjust the ignition timing based on that, which can cause problems as well.

 

This is why I'm telling you to get rid of codes.  Always start with what you "KNOW" is wrong and fix that.  Don't go jumping off on tangents until you fix what you know is wrong.  

 

Once you can clear codes and not get any back your ready to move onto mechanical stuff or things the ECU isn't going to report.

 

That ECU is controlling the air/fuel mixture and the ignition timing.

  • Author

Hmmm? I unplugged the MAF and tried to start it in limp mode but still no luck. I sprayed starting fluid into the throttle body with wide open throttle and cranked it over and didn't get jack. Nothing.

Alright. Back to square one. Are you SURE you're getting spark?

When you checked for spark before, how long did you crank it? 2-3 seconds? 10 seconds?

  • Author

Alright. Back to square one. Are you SURE you're getting spark?

When you checked for spark before, how long did you crank it? 2-3 seconds? 10 seconds?

Cranked it for at least ten seconds when checking for spark. I had two different family members watch a spark plug while I cranked it over and they both said it was sparking. (Not a intense blue-white spark, but more of a weak orange spark). I also put one of those value bin flash gizmo's between the coil and a plug wire and it also flashed while cranking.

Edited by darsdoug

  • Author

I'm going to figure this thing out even if it takes me all winter. I'm trying to keep my humor but I am rapidly reaching the WTF? point.

Edited by darsdoug

Kicks and giggles put an extension or something against the outside edge of the crank sprocket and smack it with a hammer (preferably a dead blow) to make sure it's seated all the way in.

 

Next inspect the CPS (Crank Position Sensor) and make sure there is no visible signs of damage, maybe clean the contacts a bit.

 

I'm not saying it will start after this, but it's worth a shot to try.  Especially if it's been cranked over and over with the crank pulley off.

  • Author

This morning I unplugged all the injectors (at the injectors) and gave it a spray of starting fluid and it started right up (even though short lived) I plugged the injectors back in and again tried to start it but again got no response. The spark plugs are still getting gas fouled. On the upside I removed all four spark plugs and spun it over and did not see any gas blasting out of the plug holes. Nor has the oil level on the dipstick increased due to fuel finding it's way into the crankcase.

Edited by darsdoug

  • Author

Will it keep running on starting fluid?

I don't really know? I plugged the injector pigtails back in immediately afterwards. I'll give it another try tomorrow and see what happens? I've been refraining from throwing parts at it due to the high cost. I'd like to pinpoint the cause of failure first. I'm getting 17.5 K-ohms of secondary resistance on coil terminals 1&2 and 3&4.

Edited by darsdoug

I don't like to throw parts either. They leave dents. Some of 'em can fly pretty far though!

 

 

Might check the voltage at the coil (center/yellow wire). Low voltage would cause a weak spark.

 

If the starting fluid keeps it running rent/borrow a fuel pressure guage and see what kind of fuel pressure its making.

  • Author

I see the ignition switch had been replaced at some point in the past. (I found previous switch w/ keys in a sandwich bag under front seat). My question right now is will it damage the ECM if I put a hotwire from + post of battery to center/yellow wire at coil? Just to see if it will run?

You had it running with starter fluid right?  If it ran and started with starter fluid have you done as Fairtax mentioned and tried to keep it running with starter fluid?

 

If it starts, runs, and will keep running with starter fluid you don't have a spark issue it's a fuel issue.

 

The hot wire to the coil is going to do damage and not good.  You have an igniter on the back firewall that goes before the coil to create spark.  And, IIRC, that igniter doesn't receive "constant" signal from the ECU but an intermittent signal as the ECU itself controls the ignition timing.  A straight hot wire isn't going to give you the correct spark.

 

This isn't like a car with a distributor where the ignition timing was controlled by the rotation of the engine.  

 

Let's backup a second.  

 

1.)  Did you clear codes?

 

2.)  After clearing those codes did any return?

 

3.)  Did you attempt a start as recommended by fairtax and keep spraying to see if it continues to run?

 

4.)  Have you checked fuel pressure yet?  (You can rent a gauge set at most auto parts stores for free w/ a deposit or buy one at harbor freight)

 

You need to do things in order.  Running wires and such tends to cause problems.  If you don't have a Digital Multimeter go to walmart or someplace and buy a cheap one.  Even if its cheap and out of calibration it's still going to show you whats going on for the most part.

  • Author

Had the battery out for an hour and still getting the same codes. I'm off to find a fuel pressure tester right now. Are both the coil and MAF vehicle specific? Automatic  vs. Manual?

opposedforces.com and you can cross reference which vehicles/years have the same part numbers.

 

The coil should not be different between an auto/manual.  

 

Either you have a faulty MAF or a wiring issue somewhere.  

 

A wiring issue could be causing all your problems though.  Have you verified all the harness connections are tight?  Specifically the ones that connect the engine harness, etc... to the main harness.  I would also follow the MAF one back and check to make sure it's connected tight as well.

  • Author

I got it to run on starting fluid for about 30 seconds today with the MAF and injectors unplugged (just chugging away ha ha) I checked the codes again and now I'm getting 14,15,16,17, 22, 23, 31, and 49. I put another fuel regulator on it (a used one from a 94 Impreza) but it made no difference. Where is a good place to by a fuel pressure tester cheap? O'Reilly's wants $109.00 to rent one. You can almost get a new kidney for that! 

I think I'll go junkyard searching tomorrow and see what I can find? Another complete intake might do the trick eh?

 

opposedforces.com and you can cross reference which vehicles/years have the same part numbers.

 

The coil should not be different between an auto/manual.  

 

Either you have a faulty MAF or a wiring issue somewhere.  

 

A wiring issue could be causing all your problems though.  Have you verified all the harness connections are tight?  Specifically the ones that connect the engine harness, etc... to the main harness.  I would also follow the MAF one back and check to make sure it's connected tight as well.

Autozone in Burien, Wa. has

a Duralast coil for $79.99 and it say's "with manual transmission'. I'll check the pig tails to the main harness and make sure they are plugged in all the way. Thanks.

I would start by checking opposedforces.com and going to the Junkyard to find a MAF that matches (maybe grab 2?).  Then try that and see what happens.  I don't think your MAF is the problem.

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