My Car Studders

[Talk2meYou]

I have a 96 Park Ave. 3800 with 254000 miles. Until today it ran like new. Today it started trying to stall or studder when I give it gas. It seems to run fine on level ground and just holding speed but from a dead stop or giving it gas when it is moving it seems to be missing. I haven't messed with a car in years and am not sure where to start. Help please?

[ZiggyPA]

Start with the easy things first and check spark plugs and ignition wires.

[Talk2meYou]

O changed the spark plugs and it seem to fix the problem. The plugs looked great. A few days later it came back. It only shudders after it is moving and then only when I try to accelerate. I don;t think the transmission fluid and filter have been changed in over 100K mikes. I am going to do that tomarrow. Any other ideas would greatly be appreciated.

Mike

[TopherS]

I had a similar problem with my 95 Roadmaster sedan. The car would shudder on level ground or very slight incline whenever I would accelerate. I was told that my water pump was leaking and the antifreeze was getting on and affecting some electronic part of the ignition system. I realize the two cars are very different, but perhaps this may give you good leads on possible culprits...

Good luck.

[HotZ28]

Originally Posted by TopherS

I had a similar problem with my 95 Roadmaster sedan. The car would shudder on level ground or very slight incline whenever I would accelerate. I was told that my water pump was leaking and the antifreeze was getting on and affecting some electronic part of the ignition system. I realize the two cars are very different, but perhaps this may give you good leads on possible culprits...Good luck.

Water pump leaking on an Optispark & causing misfire is quite common on the LT1 Roadmaster, but this does not apply in the case of a Park Avenue. When you changed the plugs, you lowered the resistance somewhat, but not enough. Change the wires with ACDelco, Belden or MSD. You could have a weak coil also, but that can be determined after the wire change.

[Talk2meYou]

Originally Posted by HotZ28

Water pump leaking on an Optispark & causing misfire is quite common on the LT1 Roadmaster, but this does not apply in the case of a Park Avenue. When you changed the plugs, you lowered the resistance somewhat, but not enough. Change the wires with ACDelco, Belden or MSD. You could have a weak coil also, but that can be determined after the wire change.

I ohmed out the coils and they were the same. A friend told me it could be my overdrive lockout (?). With 258K on it I don't think I am going to invest much money into it. I will try p[lug wires. Thanks
Also, dude, your on fire "HOT" is way cool.

[imidazol97]

Originally Posted by Talk2meYou

It only shudders after it is moving and then only when I try to accelerate.

Does it show the stutter at speeds just above lockup in 4th? E.g., 50-60?
Then is it gone if you're going 70 and increase throttle slightly?

Does it smooth out when you open the throttle even more giving it more air and more fuel? Running at a constant speed locked up in 4th gear and then slightly increasing the throttle opening such as for a slight hill will cause bad plugs/ wires/ to show their miss. Increasing throttle more without downshifting made it go away with the richer mixture.

Did you check the coils both at the high voltage terminals and the low voltage primary circuit on the underside? Check the contacts with the Spark control Module? Were the coils good and hot?

Don't give up. This may be something relatively inexpensive to fix.