DoBravery

1998 3.8L 160K miles auto.
Hello everyone. I guess the first post of most new members is about some problem and their looking for answers. Well I won't dissapoint. After driving a while and warmed up, my Mustang will sometimes experiences a sudden loss of power. Typically after stopping or slowing down. When I hit the gas again it just sort of bogs and stutters. I can hold the gas lightly and it will go about 20mph. If I pull over/turn off and maybe wait 4-5 min, it will drive fine again. I'm not hearing any weird noise from the tranny. Temp gauge is normal/air dam intact. Cleaned MAF which improved ride but didn't solve. Changed plugs, wires, fuel & air filters.

Could the Throttle Position Sensor do this? Other times it will accelerate fine so I hope its not the fuel pump?
The pain is that it hasn't happened yet in a situation that I could test for. If I took it to a mechanic now they'd say "It ran fine for me."
Does anyone have any suggestions or has had this happen to them?

03YellowPony

What was the weather conditions?? Yes, I have a purpose in the question...

DoBravery

Late afternoon, no rain, mid 80's (S.Florida). What was odd is that I worked the night before and had the car idling/moving for 1.5 hrs then took the interstate home in the cool morning-no problems. It happened later in the afternoon. Same interstate distance-did 70-80mph just fine. I exited and about 1 min later when I go to accelerate, it said no. I was still able to go about 30mph. Did it twice yesterday. Each time after driving atleast 25 minutes.
Next time I'll shut it off and then on. Sensor? Maybe its overheating or some part is heat soaking.

Protoman84

I had similar problems when I had to change my fuel pump.

03YellowPony

This is VERY rare nowadays, but maybe vapor lock...check the gas cap. Make sure it's venting properly. Any smog inspection station should have the equipment to check it.

DoBravery

Would a 98 Mustang V6 have a Fuel Inertia Switch? I may replace the Fuel Relay anyway. Does anyone know wich one it is?

03YellowPony

Sure does. It's in the trunk on the left side. Check it and make sure it's not tripped.

eclipsegt

Maybe the engine is either about to do or the compression isnt right in all the cylinders, 160k is a lot on an auto mustang

ByPopularDemand

does the engine rev without you touching the gas

DoBravery

I hope the compression is ok. I can tell that the previous owner changed a head gasket. We bought it at 20K miles, and I must say its been perfect up till this. I'm really hoping it's the Inertia Switch acting funny. Now that I think of it, about the same time it started happening the car was hit while parked (no note [:@]) in the driver's rear quarter. Due to the highway commute, I thought it was heat related. I'm just going to replace and see.

The car doesn't over rev. I know that's a sign of a bad relay. I figured I might switch that anyway.

We drove the car all day yesterday without a problem?
I'll let you all know what happens.