Bad stumble under load

[Buick3.8]

hey all. Im new here. Just picked up a 95 with 158k on the motor. RUNS GREAT. Only problem that i've noticed is that under a load it will stumble for some reason. Say if you drive nice and slow it wont do it..and your at about 50...then give it a little bit more gas to get upto 60-65...it'll feel like its a really bad miss. anyone have any problems like this? Im thinking either a fuel problem or TPS problem? any help would be great. Thanks


Justin
New Baltimore, MI

[maxwedge]

Welcome to AF, plugs and wires are your most common source of this condition.

[Buick3.8]

Hey thanks for the welcome. As for plugs and wires, what does everyone usually go with? i dont want cheap..But i dont want really pricey pieces either. Also, since it almost has 160 on the clock...i was thinking about doing the fuel filter as well. any certain brands people like? Thanks


Justin
New Baltimore, MI

[Bassasasin]

I think your going to "Git er done!" with your plan..

Good Luck

[maxwedge]

Originally Posted by Buick3.8

Hey thanks for the welcome. As for plugs and wires, what does everyone usually go with? i dont want cheap..But i dont want really pricey pieces either. Also, since it almost has 160 on the clock...i was thinking about doing the fuel filter as well. any certain brands people like? Thanks


Justin
New Baltimore, MI

AC plugs and premium wires are the best way to go, fuel filter not too critical.

[Alibi]

Use AC Delcos, definately. Rapidfires are nice, but the multi-tipped plugs are just a gimmick. Bosch plugs are evil in this car, BTW.

[Buick3.8]

Thanks everyone. I work for a chevy dealer So as far as AC stuff thats not a problem as i get everything as cost + 10%. Thanks again

[Alibi]

If the plugs/wires don't fix it, then you should look at your ICM. Very common for one of these to start failing at 50-60mph. If the ICM checks out OK, then look into replacing the coils.

[Buick3.8]

Ok well...During the week the MIL came on. well i had one of the techs take a look at it with the tech 2..and came up TPS low voltage...should be .5-4.5(give or take)...it was reading .1-.7...umm yea thats bad.

So..today i did plugs, wires, TPS, took the throttle body off and cleaned all the carbon out of it(was REALLY BAD). bolted everything back together...and what do ya know...an upper intake leak...GRRR...what next right. Well come to find out..when we were wiggling the TB loose it broke the gasket seal. Oh well..an extra 20 bucks wasnt bad. So now the upper intake is all cleaned up too

Lastly we used the Seafoam in through the brake booster hose..started it up..she runs like a champ now!. I went on a run and went WOT...WOW...for 158,000 it still has a lot of power.

Now i did noticed, that between 45-50 it has a little little stumble...But im thinking it might be where the TCC starts to kick in. Are these a common problem at all? Thats the only thing i could think of, other then just some carbon still in the motor. But Thanks for the help all...she runs great now.

[Bassasasin]

Change the transmission oil out.. may smooth up the TCC, whatever.. you spoke of... Most of the little slip you mention is abated with new oil....

Happy to hear your drivin great.