My truck is having a hard time starting. When idling the pump pressure 14. When going 70 it is 11. When trying to start it is 0. I now get the p0216 code and 1693 companion code. It is possible low pressure set off the codes so let's hope that is the case. The codes came a few days after the hard starting started. I have a new oem lift pump. 730k miles.

Ok... Lets go over this carefully... Watch the video on testing starting pressure...

http-~~-//www.youtube.com/watch?v=NCJjMzRImpA

The 3 pound drop is marginal and so is the 11 PSI at 70 MPH... It possible the P0216 is caused from the low pressure. But I would suggest you at least upgrade to the Vulcan Big Line Kit... http://www.vulcanperformance.com/Draw-S ... ps9804.htm

I took the relay out and turned the key. The pressure went to 0 and it still didn't turn with much strength. When I let the key go the pressure went to 14.

There should be modulated power being sent to the lift pump in pulses (ON/OFF/ON) while cranking. You might check with a test light if you can.You said the lift pump is stock correct? And hooked to the stock connector right? :confused:

It is all stock. This kind of acts like a bad battery doesn't it? I will try testing the power output.

As you can see there is only the ECM controlling the fuel pump circuit.

With the miltimeter attached to the lift pump and the relay removed it goes from 1.3 volts to 3.3 volts.

Check the ground for that circuit... The ground is behind the starter and the only way to verify this is to remove the starter. So if you got the time to pull it out and check... That all I can think off... You might end up hooking a relay up that triggered by the key and get the pump going... There is something wrong with the ECM feed... It should pulse up and down 12V - 0V - 12V - 0V... Maybe you DVM is slow to update the fast pulses? :confused:

Is it possible that a bad battery would cause this? The truck cranks at half the speed of the one in the video.

If your cranking voltage is below 10.5 Volts then the batteries or supply cables could be to blame. You might check the starter contacts... As a matter of fact give me a bit of time I'll get pics of my Mom's starter thats pulled apart. Its a gasser starter but the contacts are the same setup..

Mike,If he is low on voltage, then cranks, its going to go way down and wonder if this is robbing the ECM of the power to sent to the pump? If the engine in the truck with the problem is cranking slow, fix that first then tackle the ECM issue. Maybe that once you get battery volts and cranking speed where it should be that there will be enough voltage to trigger and run the LP.Joe

My truck is having a hard time starting. When idling the pump pressure 14. When going 70 it is 11. When trying to start it is 0. I now get the p0216 code and 1693 companion code. It is possible low pressure set off the codes so let's hope that is the case. The codes came a few days after the hard starting started. I have a new oem lift pump. 730k miles.

Check the connector tube O-rings

My truck is having a hard time starting. When idling the pump pressure 14. When going 70 it is 11. When trying to start it is 0. I now get the p0216 code and 1693 companion code. It is possible low pressure set off the codes so let's hope that is the case. The codes came a few days after the hard starting started. I have a new oem lift pump. 730k miles.

My suspicion is that the VP-44 is dead and this may be the reason why the ECM is not delivering proper voltage to the lift pump. Wow! After reading your truck profile, I am amazed that the VP-44 lasted as long as it did. The OEM lift pump is NOT up to much more than stock application and even then barely capable. The P0216 code is not going to reset. http://www.bluechipdiesel.com/injectionpumpfailures.html P0216 = Fuel Injection Pump Timing Failure You are VERY likely going to have to replace the injection pump. It may run for a long time in this condition with degraded and irradic performance but eventually it will fail altogether and leave you stranded. With mods such as what you have installed, you need the Airdog or FASS pump and as already mentioned the Vulcan 1/2 big line kit. The stock OEM Carter pumps are junk. The Airtex pumps are substantially better, especially if they are relocated to the frame below the tank but they are not up to any type of major mod or boxes. If the engine will run now and does not sound like it will, you may be able to squeeze a bit more life out of the crippled VP-44 if you install an Airdog or FASS. Once these pumps start to go, they typically gradually get worse until they crap out altogether. I would suggest you still verify the system voltage coming from your batteries. One of both of the batteries may be weak or bad. This could draw the voltage down far below specified. In addition to this, the heater grids cycle below about 60 degrees on ignition activation and will draw the system voltage down even worse. This may be a cause for such low voltage to your lift pump as well. Sorry to be the bearer of bad news.

Edited November 17, 200915 yr by LiveOak