98 -3800 - Stumble under load

[NaturalIce]

Hey,

I have a 98 Firebird with a 3800 and it runs fine except going up a good hill and that's where it stumbles.

New plugs - gapped a .50 - I know that's wrong my fault but I dont want to take them out unless I have to. ---NO fun.
New wires
New Coils

Fuel pressure is fine

No codes.

Any ideas?
IG control moduel????
Sensor?

Thanks

[pontiac imp]

Did you ever find out what this was?

I have the identical problem...no codes...can't figure what it might be.

Thanks.

[NaturalIce]

Sure did! After replacing the plugs/wires/coils the stumble got better but was still there. I gave up and took it to a shop. They decieded it was the fuel injectors. Of course $850 later it was still there and they just wanted to hurry me out the door. They had no clue. (Some mechanics ) Any way I went back to the basics and decieded to OHM out the plug wires. Brand new Autozone Durabunk wires....They all Ohm'd poorly but #6 was really out of range. I ordered a set of Delco wires -they all Ohm'd much better than the Durabunk and all is good. --- Big $$$$ lesson learned ---- OHM check new plug wires before you install them.