engine problems

[mikemhp]

hello...
'97 f-250 5.4L triton, 79k miles...

check engine light came on 3 weeks ago. i took the truck to mechanic friend of mine who has the computer diag. sensor thingy.

codes that came up:P0133; P1131; P1000...
O2 sensor indicating lean, and ckt slow res. (upstream).
p1000 sy. incomplete... (?)

i have done the following: changed all the plugs, fuel filter, and 2 front O2 sensors.

the problem persists. at low to mid rpm's, the engine runs like its at half power (sputters a little like its miss-firing or something.) shifting to neutral bumps up the rpms to about 1k, and idles better than when stopped and in drive. poor acceleration from stop, sometimes shaking from the engine/front of the truck. (mild).

at higher rpms, seems to run smoother until i floor it a little (passing or accellerating on freeway) then mild sputtering again. ALSO- when the sputtering occurs, i can hear mild clicking from the radio when on AM....

I'M GETTING BAFFELED!!!!
anyone have suggestions on what else might be going on?????
thanks for any help...

[ervinj]

Have you had your egr valve checked?

ervinj

[michelq]

first need to check that you do not have vacuum leak or stiking egr make sure pressure ok should be around 30 psi when the eng runing if all ok you have bad HEGO sensor

[ModMech]

30 psi?????? What should be "30 psi"? Other than the tire pressure, NOTHING under the hood!

You should have a Vacuum reading of 15"-22" at idle, and the fuel pressure should be 45 psi at idle (or there abouts).

EGR will NOT affect acceleration, it is only at light throttle. Even if the EGR leaked (which the EEC would see, and throw a code for it), it cannot leak enough to cause dramatically low power.

You may very well have a bad ignition coil pack, or spark plug wire (as evidenced by the noise in the AM radio). That can be caused by an injector coil as well, but not likely. Spray the intake area with ether at idle, if you have a vacuum leak, the engine will speed up when you spray in the area of the leak. PLEASE do this on a cool engine! Next is fuel pressure. Now you NEED to have the actual specs for your make/model/year, but from memory it should be about 44 psi at idle (maybe a little less, no book infront of me). If it's low, you WILL have low power, and lean codes. The rough running should not be caused by fuel pressure.

[pete54ford]

Actually tire pressure should be 32psi.....just had to say that!