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ea82 not starting slight back fire and code 42


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i have an 86gl that was originally a carbed engine but now has the ea82 spfi that was swapped before i got it. it didnt have any spark but figured out it was the crank angle sensor. now when i try to start it after a couple of cranks a get a small backfire from the throttle body. i had a friend crank it while i watched the throttle body and the fuel just piles up on top of the butterfly valve till it pops. i checked the ecu and its flashing a trouble code of 42 which is the idle switch/circuit. i dont know how to procede or what to do. im guessing the throttle is too closed so the fuel is draining past the butterfly valve. please help and thank you.

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when the guy swapped it, it ran perfect then just stopped. he couldnt figure it out so he sold it to m dads coworker who messed with the distributor and got it to run for about 10 minutes. he gave up and i got it. the rotor turns and it gets spark, fuel and air.

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i have checked compression and its good, but after i put the spark plugs back in didnt make the backfire pop. i can see that it is getting gas and if i open the throttle a little bit thats when it will pop and shoot gas back out of the throttle. the spark plugs look nasty so im going to go get some knew ones and see if that does the trick. also when i took them out they didnt even look wet.

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look at the timing belts.  When the crank (#1) piston is at TDC, the dots on cam sprockets,  1 should be up and 1 should be down

 

Also, check the plug wires to make sure they are in the correct order.

Edited by Dee2
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i took out the distributor and set the flywheel mark to 0 and put it back in. its facing the #1 cylinder and it no longer back fires. one sprocket is up and one is down. the timing belt is fine. i am getting code 42 and not know the exact year of the engine its either the idle switch or the fuel injector. does anyone know about that at all?

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EA82 SPFI is the same for all years it was made, so nothing to worry about there. 

The fuel injector should click and spray a noticeable burst of fuel while cranking. 

Use an ohm meter, check for about 2 ohms between it's 2 wires.  Also check for open circuit between 1 of the wires and the throttle body.

 

I have also tested them to verify opening by applying 12V from the battery across the 2 wires - unhooked from the ECU of course.  There should be fuel pressure held for hours after a cranking, so this will spray fuel if it is working.  Do not make or break the connections near the throttle body, make and break the last connection near the battery!  Don't hold it on for a long time, just a few taps is all you need to see it functioning.

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the fuel injector works i went and got one from a junkyard and it is shooting out a pretty good amount of gas. i have the intake boot on just took it off to see if the injector was spraying. the code 42 was refereing to idle switch. i replaced the part of the throttle that holds it and the code is now gone. can anyone post a oicture of where the spark plug wires go. from my understanding cylinder 1 and 3 are on drivers side and #1 is on the firewall side. cylinder 2 and 4 are passenger side with #2 on fire wall side. if you are standing at the front of the car #1 is on the bottom left of the distributor and number 3 is bottom right and 2 is top left and 4 is top right. im thinking im wrong but if someone has some insight that would be great.

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Good job getting rid of the code.

 

Clean or replace the idle controller.

 

1. Verify distributor alignment multiple times and make sure it's dead on. Easy to be a tooth off.

 

2. Same with timing marks.

 

3. Same with plug wires as you're attempting. Make sure they're correct on the plug side and disty side.

 

4. Pull cap and make sure cap and rotor are functional.

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the fuel injector works i went and got one from a junkyard and it is shooting out a pretty good amount of gas. i have the intake boot on just took it off to see if the injector was spraying. the code 42 was refereing to idle switch. i replaced the part of the throttle that holds it and the code is now gone. can anyone post a oicture of where the spark plug wires go. from my understanding cylinder 1 and 3 are on drivers side and #1 is on the firewall side. cylinder 2 and 4 are passenger side with #2 on fire wall side. if you are standing at the front of the car #1 is on the bottom left of the distributor and number 3 is bottom right and 2 is top left and 4 is top right. im thinking im wrong but if someone has some insight that would be great.

Passenger side front cylinder is #1 Drivers side front cylinder is #2

 

Passenger side rear cylinder is #3 Drivers side rear cylinder is #4

 

On the distributor you will hook up the leads counter clock wise in this succession #1 #3 #2 #4

 

#1 cylinder on the disty cap is the one that faces rearmost to the

firewall. its will be closest to the clip or screw for the cap on the

back side. the screw will be slightly to the right of the #1 connection

 

the rotor rotates counter clockwise,

 

Edited by Dee2
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so i put my wires in the correct spot with no change. i just took out the disty and re aligned it with the timing marks amd made sure it was ponting at number 1. the battery died so i cant try it but i noticed the ecu is flashing 5 short blinking lights. i now there isnt a code for that but is it a bad thing.

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ok thank you for that. i put it into D-mode and im getting 11 and 13 crank angle sensor. it is not getting spark. i replaced it earlier with a used one but its out again. im going to buy a new one but the only place i found that sells them is oriellys and its $150. do you guys know of a cheaper place?

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What year is your SPFI setup from.

 

87 model SPFI computer has 2 pins for disty wiring reversed versus all later models.  But it is easier to swap pins at the disty connector to correct and use later dirty with ECU or vice versa.

 

IIRC you switch the position of the Green and White wires at the disty connector.  they are diagonal from each other in the connector.

 

Just a Thought.......probably not your issue if it ever ran with your setup.

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