Hello all,

My 1993 Lumina APV (3800 V6) has recently starting sputtering upon acceleration (say at least half throttle). It is worst in 4th gear at lower speeds. I changed the Fuel filter with no imrovement. It is not the gas either. Any thoughts of what to try next?? I have a new universal catalytic converter so that is not it also.

Thanks alot,

Ravi

p.*. I tried the search feature but it is not working well for me. :(

plugs and wires.

90% of the solutions to your symptoms are ignition related. Either a plug or wire. A bad coil would knock out two cylinders all the time, being much more obvious.

I agree with the plugs and wires. Use only quality original equipment type wires and plugs. Don't get the super duper red box wires at the local box store. I used AC and Belden in past.

Also if you're getting a roughness only at about 50 with the TCC locked up under a light acceleration up a slight grade that goes away with higher throttle openings that would be something I had with my 93 leSabre. The dealer service advisor told me there was a new prom for it that adjusted the settings and the TCC lockup speeds slightlyl so you don't feel what was inherent engine roughness. I had replaced fairly new plugs and wires at about 80K because I was getting a roughness. I think it was under a $100 to replace it at the dealer. I thought I had EGR problems but that wasn't it either. Just a PROM change for a roughness you can feel because the converter clutch locks up 100%. Later leSabres have the 4T65E trans that doesn't lock up the clutch 100% and cushions the roughness if it'* present in later Series II motors.

Sorry for the stupid response but how often do you guys recommend plugs/wires be changed?

Thanks alot,

Ravi

we have no idea how many miles are on you motor, and if you have ever changed them. Your replacement wires will more than likely carry a lifetime warranty, only needing changing they go bad. If you have your stock plugs and they are iridiuims, they generally are good for 100K. But that doesn't mean something can't happen to them. With fresh iridiums and wires, you may not need to change them ever again, unless something goes bad.

Thanks for the info. The plugs/wires were changed about 30,000km ago with GM replacements. I will have them checked and report findings.

Ravi

At night, start the engine and let it idle. Spray a mist of water over the engine and watch for arcs. If you find any, replace the wires.

Pull all six plugs and 'read' them. They can tell a story.

Check the resistance of each wire with an ohmmeter. The resistance should be an increasing progression from 1-3, and a little higher even progression for 2-6. Make sure you move the wires around (twisting and bending) while checking them to identify intermittent opens (conductor breaks).

vac lines?

Vacuum lines