More Misfiring On A 3.8 :0

[Dawizman]

Well, I was out at the mall saturday, right before I was about to head out of town for the weekend. The car was running fine previously, but about half-way to pick my friend up it started running weird. At low rpm's & light acceleration it runs just fine, but it wont go above 3500-4000rpm when its warm or 4500rpm when its cold, and when I really punch the throttle it bogs down right away. I parked the car saturday and we took his mustang out of town.

I hooked up my OBD-II scanner when I got home last night and it wasnt pulling any codes. I went to start it and it would run for a second before it stalled. When I finally got it running and took it for a drive it did the same things I mentioned above. I got back to the house and re-scanned the codes and pulled nothing.

Anyway, I have a feeling its the plug wires that have gone bad due to heat (I had nearly the same problem on my old car), so I'll change them tonight.

What are your thoughts on this if plug wires dont fix it?

[97rs4life]

Re: More Misfiring On A 3.8 :0

have you recently changed the fuel filter or done a good tune up with the car? Might just need a good tuneup with plugs, wires, fuel filter, etc.

[slow6]

Re: More Misfiring On A 3.8 :0

my car has been missing horribly
I just changed plugs, wires, coils, ICM, and running back on stock injector tune, so obviously my injectors must be clogged @ 38k miles

[Dawizman]

Re: More Misfiring On A 3.8 :0

Well I went and changed the plugs & wires tonight and the problem didnt go away. I'm not pulling any codes, but according to the scanner, one of the o2 sensors might be going bad. Could this be causing problems like this, or should I be swapping out my ICM & Coils? How much do they cost?

Also, a tip for anyone working near you starter: Either disconnect the battery or remove all jewlery.
When I was removing the wires on the drivers side, my gold watch connected the positive wire on the starter to a ground and I got a nice shock. I took off my watch and my wrist has a bunch of 3rd degree burns on the bottom & sides now.

[Phate]

Re: More Misfiring On A 3.8 :0

This is a shot in the dark, but i'd tell you to try it. Test your Mass Airflow Sensor. Sounds like exactly what happened to me. It wont always throw a code either, use the ohm meter and check the wires, make sure your not getting any odd pulses. If it doesnt pulse, tap on it some, see if it does.

[Dawizman]

Re: More Misfiring On A 3.8 :0

Hmm. Could bad O2 sensors cause this problem? I plugged my scanner is again and it didnt pull any codes, but it did warn me about possible 02 sensor goin bad. The more I think of it though, the o2 sensors might just be getting bad readings because of the current problems.

[cam98aro]

Re: More Misfiring On A 3.8 :0

your problem is either the fuel filter, or a cloged cat.

[Fred]

Re: More Misfiring On A 3.8 :0

or your fuel pump

[slow6]

Re: More Misfiring On A 3.8 :0

when I unplug the maf, the computer reports bad o2s wacko