My 96 F250 is a OBD1 (plug under the hood). I just got the codes 33 and 133 and I am not sure what they mean. I think 33 = EGR valve and I can not find 133 anywhere. Does anyone know what these codes mean?

 

Your truck should have all 3 digit codes not a mix of 2 and 3. I suspect you are misinterpreting your results. I bet you are getting the all clear code of 111 then a repeat of the same 111. There is a separator flash before the PCM goes into the CM code display, that is your 1 "code". Your next display is once again the all clear code (111 - 111).

 

Thanks, I think you are right. I just watched the flashes on a youtube tutorial and it was as you said. Only problem now is I am back to where I started from. The truck starts and runs good for a few seconds and then gradually declines into a rough idle and then cuts off. I can keep it running (very rough) if I continue to feather the throttle. Not sure what to try next.

 

Verify the fuel pressure with a gauge mounted on the fuel rail test port. Should maintain 32-45 PSI for a V8 engine. 4.9L I6 is in the 50-60 PSI range IIRC.

Also check to see if you are losing spark, pull a plug or use a tester on one of the plug wires. You should have a nice blue colored spark.

One of those two are dropping out.

 

Can anyone expand on this? I'm having the same issue.

 

Did you check the fuel pressure?

Did you check for spark?