Nowandlater6

Hey all, First time poster.

My 94 GP with 3.1 all stock, about a week ago started jumping rpms' and hesitating and stuttering, and at some points even stalled out. It usually only does it after about 10 min of driving, and i went to autozone today and codes came up clear. I really need help, this is my daily driver, and i depend on it to get to work. Someone Help! Thanks.

jjubeck619

have you checked your spark plugs or maybe your fuel filter?

Nowandlater6

No, I haven't. I haven't really looked into it all that much. I had a mechanic drive it, and he happens to be my uncle, but of course it drove fine when he drove it, but i'll change the plugs and fuel filter tomorrow, and keep you posted.

jjubeck619

i would probably start wih the fuel filter, especially if you've never changed it. Probably about $20.00 and 15 minutes of work

richtazz

Are you sure that A-Z's scanner is capable of pulling your codes? Many 94-95 GM cars have a hybrid plug that doesn't have the terminals in the A-B location on the ALDL so generic scan tools can't pull them. Since your car is OBD-I, you won't get random mis-fire codes if the plugs and wires are shot, so do as jjubeck suggested and tune her up first, before spending money on expensive parts you don't need. Stay away from Bosch +2 and +4 plugs, they are JUNK. Stay with AC-Delco or Autolites (on both the plugs and wires) if you can't find Delco's.

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Would you drive any better with that cell phone up your ...?!

Nowandlater6

K, changed the plugs and filter, still no change. Any other suggestions?

Nowandlater6

If it was the MAF Sensor, it would've come up in the OBD right?

wintboy

i could be way off but does it do it right after it kicks into overdrive? like it jumps back and forth? my parents have a grand prix where sometimes after it kicks into overdrive it jumps when it trys to change gears like it wants to jump forward then comes back, for them it only happens if you try to give it light gas to speed up when it is in overdrive, although i dont have a solution to this because they have had it to the trans shop and after they found out how to make it do it they couldnt figure out why it did it, i could be way off but just a suggestion and im probably wrong

wlkjr

Sometimes a bad spark plug wire will cause that.

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97 Grand Prix GT 360,000 miles as of 02-01-09
01 Duramax/Allison

richtazz

I agree with Wlkjr, you need to change the plug wires too.

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Would you drive any better with that cell phone up your ...?!

Nowandlater6

Ok. I'll change the plug wires, and i'll let you guys know what happens. Thank you very much for the suggestions.

wlkjr

Is there a chance you could have gotten some bad gas? Not likely these days but possible. Might even trying a tank of Premium if the wires don't help.

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97 Grand Prix GT 360,000 miles as of 02-01-09
01 Duramax/Allison

Nowandlater6

I thought about that too. But the other day I filled it up with some 89 instead of my usual 87 and nothing changed.

Nowandlater6

OK. Finally figured out what it is. 1 fuel injector or more went out, and since my certain engine is SFI,(Sequential Fuel Injection), when one goes out, it shuts the rest down, much like christmas tree lights. So it's gonna be about a 2-300 fix, if my uncle does it.

GravityAmp

You might try a good injector cleaner or have a shop do an injector cleaning. It don't take much to make an injector seem bad .When I priced injectors for my 90 gpse 3.1 it wasgonna be around 600 just for injectors !
Might wanna check fuel pressure too cant hurt.
Good luck You probably already have it fixed. Sorrry for late reply
Peace

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Gravityamp
1990 Pontiac GPse
3.1 L F.I.
185k