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1999 Subaru Legacy Outback
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Discussion Starter #1
All input welcome - this one has me baffled.

Last week my Son and I completed an engine swap (EJ25) from old automatic Legacy Outback ('99) onto one with a manual gearbox, but a blown motor (really bad valve blowby - no valve lash left... It was abandoned when the former owner could not restart it).

First start on the replaced engine worked beautifully - car started and ran with no issues, no leaks - all seemed good. After setting up to be road-legal went for a test drive. After 0.5k on first minor incline, car lost power. We drifted onto a side-road and tried to troubleshoot the issue.

Managed to re-start it a couple of times. It ran. As soon as we put it under load again, it died and now has settled into not wanting to start at all. Ended up getting it towed home.

Symptoms: Will 'occasionally' start, rev up and then die within ~1sec. Perhaps about 1 in 10 attempts. First attempt after reconnecting battery is more likely to work. Subsequent attempts tend to be all duds (crank - no fire).

The engine is not throwing any codes - checked via two different EBD2 readers - one basic and one more sophisticated.

There is a subtle gasoline smell after cranking - suspect through the exhaust system but have not stood there to check.

First guess was fuel. We swapped out the in-tank pickups/pump from the other vehicle (which we knew where working) and the fine fuel filter. No change. Have checked fuel feed and fuel return lines - both are running (prime, and then continuous delivery on cranking). Fuel looks good.

Second guess around airflow. Have not found any hoses or vacuum lines disconnected. Have just removed, cleaned, re-inserted MAF and 'tapped the case'. The engine started briefly and then died as before. Air filter is used, but seems in reasonable shape.

Sparkplugs were replaced about ~15k ago, and are believed good. Tested with two different coil packs (old engine and this engine). Same behaviour. As it sometimes fires, we know we are sometimes getting spark...

Crank position sensor and cam position sensor - we changed those out to the ones from the other engine. No change in behaviour. Did notice on weird thing - the sensors I put in pulsed continuity when something ferrous were pulled away. The ones I removed pulsed continuity on something ferrous touching. I thought this might be meaningful at the time - however, nothing changed.

Some modifications around the steering column were done to fit a new steering wheel. I am wondering whether that could have disturbed something - had some kind of impact.

All fuses checked - none blown.

Engine cranks strongly.

Timing belt positioning re-checked correct.

Next steps that I have:
  • checking any grounding points/connectors I may have missed or that could have jogged themselves loose.
  • Opening up the ECU area and checking all connectors (unplug, re-plug) and checking all grounding points.
And stepping up to sacrifice a mental Goat. The herd of mental chickens has obviously been insufficient to satisfy the gods of mechanical happiness...

All ideas about getting this thing running very welcome...

Thanks in anticipation

Don
 

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Registered
1999 Subaru Legacy Outback
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3 Posts
Discussion Starter #2
Found/fixed. Subtle.

Checked fuel system and feed again. All looked good.

Checked a spark lead with a spare spark plug. Nothing. Nada. Checked on C1 and C2, pulling the plug lead and using a spare spark plug, grounding the plug to the block. On third cranking got a single spark and apparently at least one other plug fired because the engine coughed. So I knew the issue was spark, and that it was unlikely the ECU was not generating a signal (why would it suddenly start mid-crank?).

When I had mated this engine to the manual transmission, the bolts used were shorter - the old engine mated to this transmission had 4 studs. The engine I transplanted only had two and for the rest I re-used bolts from the old engine/transmission. The one for the top of the starter was too long and so I substituted a shorter bolt - shorter than ideal. Also the grounding connection bracket that fits onto this bolt I had not grabbed from the other transmission during the rebuild and had jury-rigged the earth connector onto the bolt rather than using the bracket.

Long story short - the starter had a good ground; cranked like a champion. My theory is the engine block ground was dodgy and not good enough for the HF grounding required for good spark. A short drive and vibration from improperly torqued down transmission and engine mountings was enough to break it loose. Apart from disconnecting/re-mating other random connectors (which I had done before during this search) this was the only change I made and so I am pretty confident that this is what fixed it.

Subtle one.

Cheers
Don


All input welcome - this one has me baffled.

Last week my Son and I completed an engine swap (EJ25) from old automatic Legacy Outback ('99) onto one with a manual gearbox, but a blown motor (really bad valve blowby - no valve lash left... It was abandoned when the former owner could not restart it).

First start on the replaced engine worked beautifully - car started and ran with no issues, no leaks - all seemed good. After setting up to be road-legal went for a test drive. After 0.5k on first minor incline, car lost power. We drifted onto a side-road and tried to troubleshoot the issue.

Managed to re-start it a couple of times. It ran. As soon as we put it under load again, it died and now has settled into not wanting to start at all. Ended up getting it towed home.

Symptoms: Will 'occasionally' start, rev up and then die within ~1sec. Perhaps about 1 in 10 attempts. First attempt after reconnecting battery is more likely to work. Subsequent attempts tend to be all duds (crank - no fire).

The engine is not throwing any codes - checked via two different EBD2 readers - one basic and one more sophisticated.

There is a subtle gasoline smell after cranking - suspect through the exhaust system but have not stood there to check.

First guess was fuel. We swapped out the in-tank pickups/pump from the other vehicle (which we knew where working) and the fine fuel filter. No change. Have checked fuel feed and fuel return lines - both are running (prime, and then continuous delivery on cranking). Fuel looks good.

Second guess around airflow. Have not found any hoses or vacuum lines disconnected. Have just removed, cleaned, re-inserted MAF and 'tapped the case'. The engine started briefly and then died as before. Air filter is used, but seems in reasonable shape.

Sparkplugs were replaced about ~15k ago, and are believed good. Tested with two different coil packs (old engine and this engine). Same behaviour. As it sometimes fires, we know we are sometimes getting spark...

Crank position sensor and cam position sensor - we changed those out to the ones from the other engine. No change in behaviour. Did notice on weird thing - the sensors I put in pulsed continuity when something ferrous were pulled away. The ones I removed pulsed continuity on something ferrous touching. I thought this might be meaningful at the time - however, nothing changed.

Some modifications around the steering column were done to fit a new steering wheel. I am wondering whether that could have disturbed something - had some kind of impact.

All fuses checked - none blown.

Engine cranks strongly.

Timing belt positioning re-checked correct.

Next steps that I have:
  • checking any grounding points/connectors I may have missed or that could have jogged themselves loose.
  • Opening up the ECU area and checking all connectors (unplug, re-plug) and checking all grounding points.
And stepping up to sacrifice a mental Goat. The herd of mental chickens has obviously been insufficient to satisfy the gods of mechanical happiness...

All ideas about getting this thing running very welcome...

Thanks in anticipation

Don
 
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