Subaru long crank

[Matt]

2000 Subaru Outback

Ever since I have owned it its had a long cold crank condition (~2-3 seconds before a weak start) – switching from regular fuel (91) to premium (98) makes it even harder to start? if I crank it and stop, then crank again it will fire up straight away, if i let the fuel pump prime longer or multiple times it doesn’t make any difference.

Edit:
If the car has warmed up it will start instantly/normally.

There is no check engine light and no codes stored.

The car does seem to be lacking in acceleration? Doesn’t feel as snappy as my older Subaru (1996 liberty/legacy)

Things i have checked:
Timing belt replaced and checked multiple times (even a new tensioner)
o2 sensor (spare in – same deal, put the original genuine one back in)
Coolant temp sensor (spare in – same deal, put original one back in)
Ignition coil (resistance check – to spec)
Fuel pressure (above spec, new fuel filter)
Spark plugs (clean and correct gaps)
Knock sensor (spare in – same deal, put the original genuine one back in)
Valve clearance (adjusted all at 200k km)

Edit:
Battery was checked with a battery tester and passed, and jump-starting the car with another running car doesn’t change the crank time
ECU reset does nothing
Throttle body and IAC spotless and clean
Injector cleaner

Any ideas?

Topic

[Billy]

Smoke test and compression test.

[Matt]

Smoke test – negative, also checked for intake vacuum leaks.

This car has a MAP (not MAF) sensor so it shouldn’t really be effected by vacuum leaks / pirate air?

Compression test was done before a rebuild and was within spec (at least cold anyhow), i will check again this weekend if its cool enough (was 38ºC yesterday)

If i spray brake cleaner into the intake before i start the car it instantly starts up.

[Billy]

[quote=”apache_lives” post=183763]
If i spray brake cleaner into the intake before i start the car it instantly starts up.[/quote]

That just about ensures you have a fuel problem. Looks like you’ve tested fuel pressure pretty extensively. Cleaned injectors?

[Matt]

Injector cleaner every 10000km, last time i used Redline SI-1. Time for replace/remove and clean?

Could this be a MAP sensor issue?

If i put higher octane fuel the starting problem gets worse if that helps.

[Billy]

Check injector resistance, check operation w/ stethoscope, consider running a cleaner kit through them.

[Matt]

15.x ohm on all injectors

I tried a different set of injectors – exactly the same

If i for a second start the car, wait a second then try again it *instantly* starts up?

[Billy]

Do you have to top off your coolant every few weeks?

[Matt]

Head gaskets replaced because of an external coolant leak (this car has never consumed coolant) – the problem was there before and after.

[Billy]

I’ll take that as a no.

Have you checked the wiring between the ECT sensor and the ECU?

[Author]

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