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My 99' GP Needs some help :/

A failing ignition control module could produce the symptoms you're experiencing. You can take it to an Auto Zone and have it checked for free.

Also, a bad MAF can cause a poor idle and stalling problem. Un-plug it and see if anything changes.
 


The ignition control module is the piece that the coil packs bolt onto.....do you know where they are? You will have to swap the coils over to the new ICM if you are replacing this........I have the three set second edition set of the W body guide for my year grand prix from GM........the three editions total are like six inches thick......they are worth their weight in gold.
step by step directions for everything with pics. Picked them up on e bay for like thirty bucks.......get a set if you can find them
 


is the cat clogged up? my daughters mustang would run, lose power then die. cool down for 10 minutes and same problem over again, so i cut it off and no more problem!
 


badbrad said:
is the cat clogged up? my daughters mustang would run, lose power then die. cool down for 10 minutes and same problem over again, so i cut it off and no more problem!
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even though this may be true, please do not say mustang in the same thread as Grand Prix, it is just inconsiderate, thank you....
 
Liquifire said:
you check the idle air control yet? coils all good?
not sure.........just another shot in the dark...
Click to expand...

Coils are good... give good blue spark.


I don't know what the idle air control is but no I haven't checked it.

Any way to check this?

I tried taking it to a mechanic.. but they are asking for 75 bucks to check it... and they dont even guarantee me their diagnosis
 
Just barely touch the throttle while trying to start it. If it starts and runs like that, but dies when you let off the throttle, then the IAC is the problem.

Did you try changing the fuel filter yet?
 
DanGTP said:
Just barely touch the throttle while trying to start it. If it starts and runs like that, but dies when you let off the throttle, then the IAC is the problem.

Did you try changing the fuel filter yet?
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I did actually.....

Thanks I'll look into the IAC
 


wait a minute.. isn't the IAC connected to the MAF or close to it? I think I checked it already and it does spring out.

So I guess that cancels that
 
Just a shot in the dark but I know you said you replaced the fuel pump and filter but is there a way you can make sure the injectors are firing? I saw one mentioned to try starting the car with the pedal slightly depressed to see if it stays running. Did it? You said the spark was good so Im still stuck on the fuel theory. Good luck.
 
Migueldeluna said:
wait a minute.. isn't the IAC connected to the MAF or close to it? I think I checked it already and it does spring out.

So I guess that cancels that
Click to expand...

What do you mean by "it does spring out"?

The IAC is housed in the throttle body near the MAF, yes, but they are not directly connected.
 
i hope this diagram helps you locate the IAC. though you should be getting a CEL with code P0506 or P0507 if there is an issue with it. 506 is IAC system rpm low and 507 is IAC system rpm high.

iac.gif
 
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