1999 Monte Carlo sputters

[jbranning]

Hey Guys,

I would appreciate some help here. I have a 1999 Monte Carlo LS (110k miles). When I am out of town or don't happen to garage my the car for the night which leaves it exposed to moisture my Monte Carlo sputters, sometimes for 20 miles before it comes out of it. I know this occurs mainly because of moisture because I purposely let it out last night in the rain to prove this as the culprit. Once again the car proved me right. I recently just replaced the battery, alternator, & fuel pump. I have tried several times to put heat or octane booster to no avail.

Does anyone have any ideas as to what is going on, so I have a place to start trying to fix this?

Thanks,

Jon

[maxwedge]

How about the wires and plugs?

[monteguy76]

Originally Posted by jbranning

Hey Guys,

I would appreciate some help here. I have a 1999 Monte Carlo LS (110k miles). When I am out of town or don't happen to garage my the car for the night which leaves it exposed to moisture my Monte Carlo sputters, sometimes for 20 miles before it comes out of it. I know this occurs mainly because of moisture because I purposely let it out last night in the rain to prove this as the culprit. Once again the car proved me right. I recently just replaced the battery, alternator, & fuel pump. I have tried several times to put heat or octane booster to no avail.

Does anyone have any ideas as to what is going on, so I have a place to start trying to fix this?

Thanks,

Jon

check your ecm thats what my 96 monte does and i just found out yesterday it was my computer. hope it helps. its a start

[monteguy76]

check your ecm. i have the same problem with my 96 monte, and i found out yesterday it was my computer. wich runs about 120.00.hope this helps.

[andrewgrumich]

I had a similar problem with my 1999 Monte Carlo. I would suggest checking the Mass Airflow Sensor.

[richtazz]

Your car is overdue at 110k for a tune-up. Start with plugs, wires as max suggested first, before getting into expensive stuff you may not need.

[ChevroletTough]

check the spark plug wire orings, if they are shot moisture will get into the plugs and cause the car to run bad, it would take time to "dry" the wires/plugs out with your engine heat to make it run properly.

good luck!

[maxwedge]

Originally Posted by ChevroletTough

check the spark plug wire orings, if they are shot moisture will get into the plugs and cause the car to run bad, it would take time to "dry" the wires/plugs out with your engine heat to make it run properly.

good luck!

Um, what spark plug wire 0' rings on a 99?

[ChevroletTough]

Originally Posted by maxwedge

Um, what spark plug wire 0' rings on a 99?

wait a minute, he has an LS so it couldn't possibly have the 3.4.... Nevermind my post! sorry! I should reread the post before posting! ack.

[jbranning]

I have replaced the spark plugs and the spark plug wires and the car still will sputter when exposed to high humidity or moisture such as rain. Does anyone have any suggestions as to what to try next.

[richtazz]

MAF or a bad coil would be my next guess. Any CEL-on/flashing or trouble codes stored?

[fordtough]

if you have platinum plugs, switch to ngk, my 97 ran like crap, put new ngk's in it, now spinns tires. hope this helps