1990 Grand Prix running rough

melsg5

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When is the last time basic tune up was performed?
Do you have a check engine light on?
How many miles on engine?
 

Donki 1

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When is the last time basic tune up was performed?
Do you have a check engine light on?
How many miles on engine?
Just did tune up check engine light comes on 1 day then goes off next day 160 thou miles it runs good for a day shut it off next day check engine lights on it makes a loud air sucking sound then next day no sound and runs good I'm lost it has aftermarket spectra air cleaner system just can't figure it out it also starts smoking and smells when it running bad
 

melsg5

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Did you try checking what code the computer is showing. You jump two pins on the OBD 1 port and count the times the light flashes.
Google OBD 1 codes
How long have you owned this car?
The link below contains various tests you can perform
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Last edited:

Donki 1

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Did you try checking what code the computer is showing. You jump two pins on the OBD 1 port and count the times the light flashes.
Google OBD 1 codes
How long have you owned this car?
The link below contains various tests you can perform
My parents got it new I have done lot of work on it it sat for 5 years in a garage I replaced fuel pump fuel pump regulator pcv valve fuel injectors coil pack module coil packs plugs an wires new exhaust system fuel system been cleaned I notice little fuel smell in oil changed oil and filter 3 times smell is not as bad cleaned plugs several times I will do code thing next
 

melsg5

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I know you stated you replaced the fuel pressure regulator, remove the vacuum hose and see if gasoline is there, new parts can go bad.
 

Donki 1

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Came up 2 pause 4 flashes faulty connections or ignition module I put new module on there was a lot of black oil down there all over the connections I cleaned it good could there be oil stuck inside connection still plus that white paste on back of module how critical is it to have on module I didn't put any on new module
 

melsg5

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You need it to prevent heat damage to the ICM
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