• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

IP timing

When I set the out range code on Little D the guy in Pa I took the truck too said sometimes the code is difficult to remove. This is an OBD1 truck but for the life of me I cannot remember what he said you had to do. It was a special procedure so I imagine the same condition can exist with OBD2. Fortunately mine was not "hard" set, it erased the standard way. PM if you would like and I can give you his number... he might be willing to give you some help.
 
So, back to the original question of where to set the DS4 for timing purposes . . .

Didn't I recently read in a thread somewhere that, with the OBD systems, it is better to just install the pump in the OE position to let the ECM handle the rest (advancing / retarding) rather than twist the pump only to fool the ECM and get things out of harmony with the software code? And that KOJO has some updates (courtesy of a couple of folks here on TTS) on how to better handle the fuel curves and IP timing based on power demands?
 
Well the thing is that i can't get rid of the tdc code long enough to do a relearn.
i had the Batts disconnected overnight and after them hooking back up the code stayed away on first start but after shut down but on restart to attempt a relearn with KOKO the code reared his ugly face again.

AllData says if TDC offset code -2.46.. can't be deleted with the IP in base setting,...Replace IP!
That kinda makes me think that the problem lies with the IP,..could it be that the advance piston is bottomed out and got stuck or the steppermotor turned to the far end of its swing and got stuck?
 
There is a thread on TTS on a procedure to get rid of code so KOKO still works. I'll see if I bookmarked it. I can't remember what I did, but it worked for me on my ip swap with same problem.
 
bison said:
Well the thing is that i can't get rid of the tdc code long enough to do a relearn.
i had the Batts disconnected overnight and after them hooking back up the code stayed away on first start but after shut down but on restart to attempt a relearn with KOKO the code reared his ugly face again.

AllData says if TDC offset code -2.46.. can't be deleted with the IP in base setting,...Replace IP!
That kinda makes me think that the problem lies with the IP,..could it be that the advance piston is bottomed out and got stuck or the steppermotor turned to the far end of its swing and got stuck?
Click to expand...

Bingo!.

I took the stepper motor off the IP and compared the position of the screw rod with a couple other steppers i have on my selection of IP's.
The rod on the stepper i took off is 6mm further extended( and the cause of DTC P1214 being set) than the rods on any of the spare steppers.

I put the stepper with the retracted rod on the IP( swapping steppers is an easy job actually), connected the batts and fired it up and did a quik scan.
CODE is GONE.:thumbsup:
Desired timing was 13, actual timing was 13, TDCO was 0.00. :D ( no time set done yet)


Pic,..The one on the left is the stepper from my truck,.the one on the right is one off a spare pump
 

Attachments

  • stepper motor DS4.jpg
    stepper motor DS4.jpg
    46.1 KB · Views: 6
Compress it by hand. Teh stepper is nothing more than IAC valve like used in a gas engine. You must have over extended it when adjusting the pump and it tried to overcompensate.
 
Great find on the stepper motor! :thumbsup:

Back to the question (for the group) on the installation for TDCO . . . Install it at OE position and let the ECM do the work or 'advance it' like a DB2?
 
JayTheCPA said:
Great find on the stepper motor! :thumbsup:

Back to the question (for the group) on the installation for TDCO . . . Install it at OE position and let the ECM do the work or 'advance it' like a DB2?
Click to expand...

No matter what, the DS4 must be timed. You have to install it in the base position, then rotate it until you get the desired TDC offset(-.5 is considered ideal by GM, but most go to -1.50- -1.94 to get a little more advance). If you get the pump 2 degrees out of time, that is 4 degrees off of total time it is out. The pump has to be put to a position so that the ECm can control it through the desired timing range. The timing marks are jsut a reference mark to start at, then you set TDCO.
 
Been cheering to soon :(

On first start this morning prior to do a relearn check engine light came on with that G-damn P1216 again:mad2:
TDCO back to -2.46. The value must be stored as default setting in the ECM ..right?.

Anyway,i moved the stepper rod back in again and decided to swap the KOJO for the original ECM, delete the code and fired it up.
Checked on the scanner were things were at.


Guess what :rolleyes5:

Desired timing ..12
Actuall timing - 25.2 ... it set a code P0216
TDCO....-2.46

Me thinks this IP has serious issues( this IP was originally on this truck when i bought it with a fried engine but it has been sitting gathering dust for 5 years)
Advance piston stuck, or????

I first installed the IP i rebuild 4 years ago but it won't pump fuel,..the plungers are stuck in the rotor(musta been some moisture gotten in sitting in my old dank shop for a couple years,same as the IP in question.

Some days one can't win.:nonod:
 
I could sell you your IP back, the dollar isn't what it used to be so the price is up.:hihi:
 
NVW said:
I could sell you your IP back, the dollar isn't what it used to be so the price is up.:hihi:
Click to expand...
You can keep the damn thing,
I have another 12 of them i can try.(Gonna throw a dart :()
I don't look forwards to go trough the hassle of R&R for a third time with an untested pump:nonod:
 
Well i think i got it licked. ;)

I wasn't ready yet to try another pump, so I took the top of the IP off to see were the advance was at by the position of the cam ring and OS.
The OS was all the way to the pass side and felt like stuck there. i took a screwdriver and pried the cam ring back and forth a few times till the advance piston loosened up till it moved freely( it was a kinda sticky at first) and then pushed the OS over to the dr side and bolted the top back on, i also moved the stepper rod back in as far as it would go, hooked the batts back up and fired it up. no codes were set
As soon as the temp hit 170 the engine stumbled and the scanner displayed TDCO - 1.85. I never even did a relearn with KOKO :???:
Desired and Actual timing are both 11.9( don't know if that is good or bad ), do i need to move the IP yet or call it good?
Fuel rate is kinda high at 5mm but that may have to do with the KOJO tow tune,..i don't know.
FS closure is 1.78 ms

What say you?
 
You must log in or register to reply here.
Back
Top