1998 Impreza OBS EJ22 No Start

[PhantomSubaru]

On 12/21/2020 at 11:26 PM, idosubaru said:

Check for vacuum leaks - Brake booster hose particularly.  Very common on Subaru’s to get pulled or forgotten. 

Thanks.  I will double check those.

[PhantomSubaru]

I noticed something yesterday that may or may not be related to the starting issue.  After pulling the key and opening the door, the open-door icon lights up on the instrument cluster as if the ignition were still turned on.  The ignition itself is kinda funky to get the key to the right place where it clicks when removing the key but I always make sure it does.  I figure if the ignition were faulty it would not crank the engine though so maybe this is a separate issue.

[idosubaru]

58 minutes ago, PhantomSubaru said:

I noticed something yesterday that may or may not be related to the starting issue.  After pulling the key and opening the door, the open-door icon lights up on the instrument cluster as if the ignition were still turned on.  The ignition itself is kinda funky to get the key to the right place where it clicks when removing the key but I always make sure it does.  I figure if the ignition were faulty it would not crank the engine though so maybe this is a separate issue.

My weak understanding is that the ignition either turns the engine over or not. It’s not fuel related.

1. No one asked about check engine lights?  What codes do you have?

2. when you turn the key do you hear the relay and pump prime?  The pump should turn on for one second.

3. Check that brake booster vacuum hose - people often miss that on engine work.

4.  Spray the starting fluid around intake hose, air box, PCV hoses to see if you have a vacuum leak. 

[Rampage]

On 12/21/2020 at 7:17 PM, PhantomSubaru said:

Next thing I did was fiddle with three large connectors on the back side of the engine, one of which goes to the injector harness.  I did not unplug them but simply wiggled them a bit to make sure they were fully seated which they seemed to be.  I tried the key again and it started.  Go figure.

Looking at the FSM wiring diagram - The B21 (20 pin) connector carries the crank and cam sensor signals to the ECM. The ECM will not trigger the injectors without those signals.

The B22 (16 pin) connector carries the 12v and ECM signals to the injectors.

[PhantomSubaru]

On 12/23/2020 at 8:25 AM, idosubaru said:

My weak understanding is that the ignition either turns the engine over or not. It’s not fuel related.

1. No one asked about check engine lights?  What codes do you have?

2. when you turn the key do you hear the relay and pump prime?  The pump should turn on for one second.

3. Check that brake booster vacuum hose - people often miss that on engine work.

4.  Spray the starting fluid around intake hose, air box, PCV hoses to see if you have a vacuum leak. 

Thank you for your input.  I was far away on vacation now back in the neighborhood.  I will double check on the codes when I return to work on the Subaru.  I know for sure the pump primes when turning the key and there is plenty of fuel pressure.  I will double check my brake booster hose and other vacuum hoses.

[PhantomSubaru]

On 12/23/2020 at 9:00 AM, Rampage said:

Looking at the FSM wiring diagram - The B21 (20 pin) connector carries the crank and cam sensor signals to the ECM. The ECM will not trigger the injectors without those signals.

The B22 (16 pin) connector carries the 12v and ECM signals to the injectors.

Thank you for your input.  I was far away on vacation now back in the neighborhood.  It sounds like either one of those plugs being loose would cause non-starting issues.  They seemed to be tight but maybe not quite fully seated in their proper placement.  Or else I have a poor ground somewhere else or loose connection which would explain the intermittent starting.  I hate electrical issues but at least I am learning things along the way.

[Rampage]

2 hours ago, PhantomSubaru said:

It sounds like either one of those plugs being loose would cause non-starting issues.  They seemed to be tight but maybe not quite fully seated in their proper placement.

When connecting those plugs listen for the click when it latches. It has to compress a rubber seal on the inside.

With the engine running use needle nose pliers and wiggle and pull on each wire of both connectors both sides and see if the engine stalls.