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1990 5.7 tbi will not idle and lacks power???

I love my Chevy Chevette!
Posts: 1
Joined: 06/10
Posted: 06/15/10 08:52 PM

I have a 1990 fullsize Blazer that has me stumpped. I have no power and it will not idle. my code reader is stating that I have an ignition sensor problem. I have now replaced all electronic components in my ing. system except for the pick up coil and the distributer itself. What are the symptoms of the pick up coil being bad??? It's my understanding that it either works or it doesn't...  

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Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 06/16/10 07:01 AM

i am taking that this is a small cap HEI..

get a bright flashlight... pull the cap and rotor....    where the rotor pushes on... look straight down the shaft...

you will see a riveted on plate. that is the reluctor... look at the center hole... exposed next to the shaft  you can see a bit of the ring magnet that is just below the plate... see if you see any CRACKS...   if you see any cracks in the magnet...

find a reman distributer.. if you have an autozone nearby.. they have reman distributers for about 100 bucks...  with a totally improved design  reluctor and pick up coil....  they come with a new modules installed...  usually a transpo.. those are decent modules.. so don't worry about it..

if you take the cap off....  figure out which way the rotor points when its aiming at the #1 wire position... then turn the crank until the tips of  the reluctor and the tips of the pick up coil line up exactly...

look at the crank timing marks... this is where the engine is going to fire the engine at..    you can now remove the distributer...    install the new one...  once you get the rotor pointing at the proper angle and the housing is down on the pump drive..      you can turn the housing to line up the reluctor tips and the pick up coil tips then lock the distributer down.. it will fire up easy right there..  and be really close...  so you don't have to turn the housing while you are cranking..   i do this and people think i am a magic mechanic..  

while you are up on top of the motor...    pull the coil. look at it closely... see any burn marks... white dots on the core near the external frame...  they leak high voltage and cause misfiring...  

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I love my Chevy Chevette!
Posts: 19
Joined: 04/08
Posted: 06/18/10 03:01 PM

you may also test the knock sensor on the passenger side block drain hole if it is bad or has a bad connection it retards the timing to a pre determined safe point  

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