Random issue

[James65]

My 97 6.5td has a problem where I would be driving and all of a sudden it will start running rough and blow white smoke and when I turn it off and start it again it would be running find. Also my fuel gauge is jumpy.

 

[Wreckinball67]

Check your ground wires. Sounds like the computer is losing ground intermittently.

 

[James65]

Ok I will thanks.

 

[MrMarty51]

Fuel gsuges on these trucks does move around quite a bit, not at a real rapid pace but just always moving. I just take an average and if it gets any where close to the red marks near the E mark, I better be fueling it up cause it is EMPTY. LOL
Welcome to the forum james.

 

[James65]

Thanks that's nice to know.

 

[JMJNet]

You need to fill up before it hits 1/4 mark on the fuel gauge.
If it is jumpy, it is a little bit for difficult to judge, though.

 

[WarWagon]

Check for codes.

Put a clear return line on the IP to check for air. When the engine acts up immediately stop, shut it off, pop the hood, and look for air in the line. The #1 step is to check for air in fuel lines. Step #2 is lift pump failure test and then #1 check for air. Air screws these IP's up guaranteed. Lift pumps fail and depending on the year the OPS switch may be the cause. Later years use a relay: earlier years use the OPS direct.

Grounds: You take these apart and clean them, period. Looks are an excuse to miss the problem. The ECM by the trans dipstick bolt top rear of engine, ground on IP, both battery grounds, positive cables, and load test each battery separately.

GM fuel senders are beyond bean counter cheap. The fuel eventually ruins them. Replacement is likely in your future and while you are there get rid of the sock/screen in the tank on the fuel pickup. A clogged sock can be trouble. A indestructible aftermarket sender is sold here: http://leroydiesel.com/products/metrum-rod-fsu/

 

[James65]

I am back again for help.

Recently my truck has been starting to run rough and puff smoke when it would get around 170 degrees and then throw 2 codes, p1214 and p0216. The most recent time this happened it's was worse it didn't clear up after I turned it off, it would kinda start for a split second then die again. But it did make it home after I let it cool down for a while. I checked the codes again after that last incident and it was only p1214

 

[Husker6.5]

P0216 - Injection Timing Control Circuit -
Stepper Motor. DTC sets when there is a 5° difference between Actual Injection Timing and the Desired Injection Timing.

The D.I.T. defines the current position of the piston in relationship to TDC. The circuit measures the difference between Desired timing to measured (Actual) timing.

P1214 - Injection Pump Timing Offset - Crank Position Sensor. Conditions for setting the DTC:
The TDC offset is greater than 2.46 degrees
or
The TDC offset is less than -2.46 degrees

CIRCUIT DESCRIPTION

The PCM has the ability to determine the amount of offset needed to bring the engine to top dead center. This is used by the PCM to determine proper injection time

 

[James65]

What do you think is the first thing I should check/replace?

 

[Husker6.5]

#1 I know we said "Grounds, grounds, grounds!" and you checked and cleaned them. BUT, go back and make sure the two ground studs, the threads and nuts on the passenger side rear of the intake manifold are shiny metal clean, as are the wiring eyelet terminals, and use a star washer between the top nut and the terminal stack for maximum conductivity.

#2 Check both halves of any wiring connectors (stepper motor & CPS) for dirt/corrosion/bent pins. Check the shell half going to the PCM for continuity to ground (Black) for the CPS. The leads to the stepper motor are not grounds, they are position coil inputs that move the plunger in and out to match the timing demand from the PCM.

#3 If cleaning/trouble shooting of grounds and connector halves doesn't fix the problem, your most likely culprit is the CPS being bad. My guess on the first time setting both codes was because the stepper motor could not compensate to the amount of timing difference being sent to the PCM by the CPS, so it coded too. The second time the CPS was sending an out of spec signal for degrees of offset to the PCM, but the stepper motor could compensate.

 

[Husker6.5]

Check for smashed wire(s)/missing insulation/pull out on top of the sensor on the CPS itself as it is such a PIA to get out/in, that many times its pigtail gets damaged. When replacing the CPS (or ANY sensor/sender) !ONLY! use genuine AC Delco parts! Can NOT stress that enough! @RockAutoLLC carries AC Delco and cheaper than the mass market auto parts chain stores.

 

[WarWagon]

So do a bunch off stuff and throw a bunch of parts at it and get nowhere.... or start telling us about any bubbles in the clear return line on the injection pump. Again, start with checking for air in fuel because air can cause all kinds of problems and set all kinds of codes.

 

[ak diesel driver]

Do the cheap easy stuff first. Check for air, check grounds and use an ohm meter to check that back stud to the battery ground as the stud itself can lose it's ground. You can check the CPS and OS by unplugging the OS (with the engine off) and then try to start it. It will take ALOT of cranking to start and when it does it will be in limp mode. If it won't start or runs rough or messes up in any way then the CPS is bad. Do the opposite and unplug the CPS to check the OS. Also have you checked the TDCO? It could just be out of time.

 

[Husker6.5]

TCDO being off can definitely screw with the stepper motor's ability to properly time the injection and with injection timing out of whack it will run like crap, smoke white, etc.

@James65 , did you do the things suggested two weeks ago by Warwagon, clear fuel line on return, checking lift pump, checking and cleaning grounds? I did make a mistake when I assumed that you had and everything checked out OK before going to my GM factory service manual to give you what the codes meant, the component they referenced to and its function in the system and what the remedy is.

PLEASE fill out your Signature, too, so we have basic info like how many miles on the vehicle/drivetrain, any performance updates/modifications to the vehicle (ie: transmission rebuilt at xxx,xxx miles, new/reman IP [vendor/rebuilder] at xxx,xxx miles, WMI added, FSD remote mounted on a cooler [location], etc.). And definitely let us know when you tried our suggestions and what the results were, so we're not trying to address multiple issues across multiple posts and not knowing what was resolved or if these are new problems popping up or old ones not yet addressed.

Thanks.

 

[James65]

Ice checked grounds and lift pump. The lift pump seems to make a faint tapping sound. And the cleared the return lines

 

[JMJNet]

It happened to mine and it turns out the CPS.
It was very intermittent/random also.

However, air in fuel system can cause that also.
Check for leaks carefully since most fuel leaks will not make it to the ground.

 

[Will L.]

Lift pumps make noise and don’t actually pump fuel all the time. Making noise means nothing.
Fuel pressure gauge says what is real.

 

[WarWagon]

In order to help you we need a clear idea of what you have done and the results of things we have suggested you try. We are not there and can't see what you are doing or have done.

 

[JMJNet]

Intermittently working lift pump can cause air that can cause what you are having.
So, the first thing to do is to make sure that the LP is pumping at the proper pressure and volume.
Then go from there.