I have my 97 suburban and it runs and starts awesome most of the time. When I think the engine is still warm and I go to start it, it wont start unless I give it some fuel by pressing on the pedal. I dont have to floor it but I have to pump it a little bit. I then get po251 code and sometimes p0335 code which I already replaced the sensor and still getting it.

Is the IP on its way out and cant suck the fuel up to get it started? I did the lift pump test and it works, But could that be causing it? PMD?

still getting code p0251 and p0335, which I already replaced the sensor.

Which sensor did you replace, 0335 is crank sensor, & 0251 is optic sensor 2 different items/locations

I replaced the crankshaft sensor but every now and then when it starts hard and throws a code I get the p0335 again.

I dont know if this makes sense but as of driving it this week, if the SES light isnt on and the engine is cold(not run in 5 hours) it starts perfect. If I run into a store and come out in 5 minutes, it starts fine. But when I leave it for an hour or so and the engine is warm, it will start hard and throw the code.

unplug water temp sensor.

unplug water temp sensor.


To Increase Glow time?

Louis

well Ive been driving it and been starting right up and no codes. Not sure why but Im happy for now.

Im new to diesels but I dont think its a glow plug issue. It will start up in 15 degrees not being plugged in.