1990 Legacy won't start

Tiny
KEVINRAY
  • MEMBER
  • 1990 SUBARU LEGACY
  • 4 CYL
  • AWD
  • MANUAL
  • 140,000 MILES
I just replaced the engine in a 1990 subaru legacy but it wont start. I did a compression check (good compression) Its getting spark to the spark plugs. Its got fuel pressure to the injuctors, my question is what (amperage?) Power do the injectors have to have because when I tested them by hooking up test light to neg and finding power then hooking test light to other side of terminal and poss. Turned engine over the test light lights up but is very very dim. Thats why I'm wondering if they run off lower amperage, (voltage?) If not why is the light so dim and will that keep the engine from starting
Thursday, July 7th, 2011 AT 12:12 AM

3 Replies

Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Use a noid lite at injector connector. Does it flash, engine cranking? Do you have voltage at injector, yellow wire, 12 volts. I don't recall if voltage goes hot with key on or cranking, try both. If you don't have any voltage find out why.

I looked at injector ohms spec, 11--12 ohms. If you divide 12 volts, if it is 12 volts by 12 ohms, you get one amp.

How long since last tune-up? Does battery have a full charge? Any applicable trouble codes? I can't tell about your test method?
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Thursday, July 7th, 2011 AT 1:18 AM
Tiny
KEVINRAY
  • MEMBER
  • 4 POSTS
Yes I have voltage at the injectors, there is voltage with the key on or off is there supposed to be voltage at the injectors with the key off? There are no codes because I just replaced the engine and it hasn't been started yet.
The injectors are the ones that came out of the engine that was in it and it was running when I took it out so I'm pretty sure the injectors are good, I checked the resistance, between 12 and 12.4 ohms, I'm going to test them with the noid light in the morning if the noid light doesnt flash what would cause the problem I'm lost on this one, could there be a problem with the ECM? If so how do I check that. Thank you for your help I really appreciate it.
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Thursday, July 7th, 2011 AT 5:27 AM
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
The replacement engine, is it compatible with computer? Did the replacement engine come out of same year--make--model, engine size?

I don't care if engine has been started or not, can you communicate with computer?
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Monday, July 11th, 2011 AT 6:23 PM

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