stickman3z

Hey all I need some help with a 86 5.0. The car starts and idles good but when the engine hot and is under load it will surge like its running out of gas or something similar. But when your cruisin on the highway its fine. Almost as if the car only has an issue while under acceration. I have checked the following: fuel pump, fuel lines, plugs, wires, and EGR valve. Some of my friends believe it could be an 02 senser, but others say an O2 doesnt have that much control over engine management. any ideas will be helpful.

mrbigshot

fuel filter, if its doing it on acceleration thats what i would look at .

5.0stanger

run the codes, it will let you know if the O2 is bad. Wouldn't hurt to repace it anyway...

stickman3z

Fuel filter is good replaced it anyway, but whats really intresting about this is after the fuel filter was changed the car ran great for about one or two miles. Then it started to do the tyipcial surging. So then I thought to re-time the car, and it ran good for about a block or so and did it again. This just got me really confused because both Fuel/spark changes fixed the car briefly. Next up code check will keep you guys posted.

dirtysanchez

throttle position sensor.

5.0stanger

Messed with the battery lately? A bad ground will do that also

Sleeper302

Spray the plugs, wires, cap, and coil down with soapy water. If it is an automatic have a friend power stall
(hold ther brake and gas while the car is in drive to stress the ignition system) the car for you, get in a dark area
and look for ignition leaks.