99 ford 350 problem

[dabaer]

I got a 99 f350 with the 7.3L. it has 275,000 miles and has recently been acting up, the check engine light will come on and then turn off while driving. Every time the light turns on or off the pickup will studder for a bit and then seem to run good after a few seconds of the studder. I had my scanner plugged into it while the light was on and it wouldn't read any codes so im just a bit lost on where to start. It also has died, i think only twice, but just when it has been at idle and the light switches. Just wandering if anyone has an idea of what to check, i would think its just a sensor that needs replacing but aint sure.

thanks

[Scott K]

So there are no codes after the light has came on? Sounds like you have a bad EBP (exhaust back pressure) sensor going bad. You can test it with a scan tool, koeo, it should be within a psi of the Map, and the baro, about 15 psi, give or take. Then while stomping on it, the psi should increase about to 28 inches. You can unplug the sensor and see if the problem continues, but the check engine light will come on since the sensor is unplugged. But you shouldnt have any big changes in drivability.

[EZ17]

Like Wandering said check the EBP but typically you wont get a CEL on a EBP sensor on a 99 model year unless its electrically open circuit(5volt reading)..If that checks out ,first I would pull the dipstick and make sure you have the proper oil level as the same oil you put in the pan is used in the injection system..may just be a simple supply issue...next I would go to the left front cylinder head and unplug the ICP sensor connector and check for presence of engine oil in the sensor/connector itself...if there is, replace the sensor and scrutinize the connector pin fit..the IPR valve can cause your condition..you'll need to monitor injection psi with your scan tool to catch this as you experience your studder..lastly you could have an undervalve cover connection issue, meaning the harness that connects the injectors and glowplugs to the valve cover gasket, which then transfers that connection to the engine harness connectors, has worked loose and is giving you an intermittent connection and causing one or more injectors to shut off..

[katophil]

I'd also look hard at ckp.

[Scott K]

I'd also look hard at ckp.

It doesnt have a ckp. The 7.3 uses the CMP to get the rpm signal.