Electrical problems relating to 1991 subaru legacy engine

[Freestone]

So this is going to be kinda weird and may take a special type of person to want to help solve. Everything I am interested in getting further input on is from a 1991 subaru legacy....it just so happens to live in a 1983 VW vanagon.

 

I Purchased this van with a 2.2L Subaru swap by Kennedy
Engineering. Drove van from Sacramento to San Diego. Did a trip to Nevada, then
the van began to have idling issues and when I went to replace the IAC valve,
found oil in the intake. Turns out the rings were toast on the old engine. Took
it to S&S performance and they put in a new engine. The engine is the only thing that was new. The
wiring harness, ecu, intake, exhaust, and all sensors were from the old
engine. After a couple weeks of driving the van, the idling issues came back.
This is what I am trying to diagnose/fix.

 

Symptoms

·       New engine ran perfectly for 450 miles

·       Rough idle developed

·       Cylinder 1& 2 not firing

·       Code 24 displaying on OBDI readout

o  Code for IAC valve

 

 New/recently serviced
items

·       New motor from S&S performance

o  450 miles on engine

·       New IAC valve

·       New TPS sensor

·       Recently serviced injectors

o  Done to see if injectors being clogged was the problem

o  3 serviced, calibrated flow rates

o  1 new

o  All OEM injectors for 1990-1991 manual Subaru Legacy

 

Diagnosing

·       Injector #1 and #2 not pulsing

o  No ticking when listening for pulse with long rod

o  Injector #3 and #4 can be heard ticking from same test

·       Swapped connectors from injector #1 à injector #3 and injector #2 à injector #4

o  Result: injector #1 and injector #2 began pulsing, injector #3 and injector #4 stopped pulsing. Engine ran worse from only getting power from two improperly timed cylinders.

 

·       With ignition ON, measured voltage at (+) ECUterminal for each injector

o  Result:

§ Injector 1: 12V (connector F47.13)

§ Injector 2: 12V (connector F47.12)

§ Injector 3: 12V (connector F47.11)

§ Injector 4: 12V (connector F47.26)

·       With ignition ON, disconnected injector
connectors, measured voltage at (+) ECU terminal for each injector

o  Result:

§ Injector 1: 0.35V (connector F47.13)

§ Injector 2: 0.45V (connector F47.12)

§ Injector 3: 0.0V (connector F47.11)

§ Injector 4: 0.25V (connector F47.26)

·       Check Continuity between (+) wires for each injector from ECU pin to injector (+) terminal

o  Result:

§ Injector 1: Continuity (connector F47.13)

§ Injector 2: Continuity (connector F47.12)

§ Injector 3: Continuity (connector F47.11)

§ Injector 4: Continuity (connector F47.26)

 

·       Check continuity between ground wires for each
injector and common ECU ground pin

o  NOTE: Seems the previous owner or someone had modified ECU. All injectors ground to one pin on the ECU, rather than the way it was originally designed where the injectors had two ground pins. The pin they are all connected to now was originally for
the “Backup Power Supply”

o  Result:

§ Injector 1: Continuity (connector B48.15)

§ Injector 2: Continuity (connector B48.15)

§ Injector 3: Continuity (connector B48.15)

§ Injector 4: Continuity (connector B48.15)

 

What I think may be the case:

·       Bad crank or cam sensor causing ECU not to pulse injector #1 and #2

·       Faulty ECU

 

Would anyone have any insight on this by any chance?? Any input would be greatly appreciated!

[wtdash]

Hi,

Nice VW...

 

I'm not the diagnostician of others on here....my .02.

 

I'd read this: http://www.ultimatesubaru.org/forum/topic/87011-91-legacy-code-24-bypass-air-control-solenoid/

 

Note Endwrench is no longer 'online' but doc may be on this resource: jdmfsm . info / Auto/Japan/Subaru/--Articles--/--Endwrench--/  (remove spaces)

 

IIRC, the '90-'91 5-speed/manual EJ22's had a specific IAC and ECU, if you decide to get another ECU.

 

Also, if the timing belt tensioner is failing, it might allow the belt to skip a tooth? The tensioners can be reused and are not always replaced during a Tbelt job.

Edited February 1, 2017 by wtdash