Help with diagnosis

[phantom309]

I bought the suburban, it's a 99, 275,000 miles
It runs great when it's cold, fires right up no smoke soundsvery crisp, after it warms up to 160 deg or so, it will barely idle with clouds of blue smoke and lopes like an old alcohol digger. It will roll down the highway on cruise just perfectly. First thing i did was plug in a good fsd on a cooler, from my pkup so i knew that was good.
To drive it you have to give it a foot full, it chugs bad and clouds of smelly unburnt fuel smoke until it gets over 1500,. Then clears itself, and runs really nice. Power is good, motor is smooth, If i two foot it i can keep it firing on all 8 with no smoke, but thats pretty hard on the brakes.
I can bring the rpm up under no load and it cleans up a runs great at 2000
The codes its giving are

PO 1214
P 236
PO 1214pd (?)

So it seems like its going waay retarded, at anything less than 1500?
Some things i read point towards a stepper valve?

Any input would be greatly appreciated,.

Thankyou
Nick

[Yukon6.2]

Hows the timing chain?

[phantom309]

I don't think the timing chain is the culprit, it runs great cold, or with temp sensor unplugged

I unplugged the ect, and the engine runs great?
I drove a 150 miles or so today,. But its just a cover up, with the ecm thinking its -39f it has lots of advance,. Plenty of power, except for no lockup, everything works great even the cruise control,.
I don't know what to do,. Its like the ecm is out of whack?

[Robyn]

The injection pump is likely the culprit.

Check the TDC OFFSET

Any evidence that the IP has been fooled with (possibly the 3 bolts are loose)

The IP should be centered in the timing chain housing with a possible scribe mark across the IP and housing... Check to see if if there are anomalies there.


A timing chain, although possible is not likely as the thing would probably have other issues.


A possibility exists that the ECM has issues, but I would check the timing and the IP before digging into the electronics.

[john8662]

PO1214 means timing offset error. The injection pump is out of it's timing range that the computer can compensate for. The engine needs to be timed using appropriate tools (bi-directional scan tool that can initiate the time set command).

Then the pump has to be physically rotated to see get the timing in range.

Sounds like it's really retarded timing by the description, most likely due to a severely worn timing chain. See if you can get it in range with the timing adjustment, if not it'll need a chain.

John

[phantom309]

I appreciate the advice,. Again,. Why would a timing chain just suddenly stretch overnite? My 94 has over 500, 000 kms and the chain is a litle sloppy but the stepper has a huge possible range of adjustment,.
I'm just about done with this obd2 crap,. I thinks its going to go to auction
I've asked a fee different experts but nobody really seems to know why,.

Thanks again

[phantom309]

I have now put on over 1000 mi on this burb, all with the ect disconnected,
I tried to do a koko relearn, i got it hot, cleared all codes the did the koko when trying to start it it would fire then stall. I did that 3 times then just pressed lightly on the throttle and kept it running at 800 or so. After a few seconds i slowly closed throttle and it idled sort of, but like a blown alcohol motor, or a cold 2 stroke detroit from 600-900 and back,.smoked pretty good while doing it.
This went on for a minute? Or so, then it stalled. Restart was real hard lots of cranking and a little throttle rough running and lots of smoke,.
I gave up unplugged the ect, and carried on.
I don't know anyone in the toronto area that can time this thing unfortunantly
So i'm looking to trick the converter to lockup,. And trick the trans temp switch so O/d works sooner,. All hillbilly workarounds i know, but this truck drives so nice lots of power, and starts really well in the cold,.

[JohnC]

Have you tried just turning the injection pump in the direction to advance the timing? Sounds like your base timing is too far retarded and the only time it runs right is when it's fully advanced.

[Robyn]

What is the story on this Burb ???

How long have you owned it ???

If you just bought it what was done to it prior to you purchasing it ???


Something has happened ...AS in IP replaced, ECM replaced maybe or ???

I have seen these things with a BAZZILLION MILES on them and the timing chain not loose enough to cause a timing issue with the TDC OFFSET.


It is possible though that the timing stepper motor (IN/ON THE IP) is having issues.

[phantom309]

Robyn, i have had it a month, i'm 2 nd owner,. It doesn't look like its ever been apart.

Here is an update,. I think i may have found the problem? I unplugged the crank sensor , after an extended crank it fired and ran just fine!! WITH the ect plugged in, so its running fine on the optical sensor only. All 4 gears and lockup! But no cruise, and idling at proper rpm.
I read somewhere that to unplug the optical sensor and if it runs fine then the OS is no good,. Same with crank sensor,..?!?! I think? the crank sensor is no good?

[Robyn]

Try a fresh crank sensor and see wassssup.

Just go easy on getting the old one out of the front cover.

Getting rough with the sensors after they been in there a long time can cause them to break off.

If that happens then the cover usually has to come off to get the beast out.


Good luck.

[Robyn]

With the Crank sensor unplugged you should get a P0335 fault code

[phantom309]

Well the bloody saga continues,. To switch crank sensor i had to loosen off the accessory drive bracket and power steering bracket, the wiring is exactly long enough and was a challenge to thread it up the right way to plug it in,. Making sure not to pinch it yada yada,. Truck fired after 2 turns and ran like a champ!!
Only for a few minutes till it warmed and then the same troubles, barely run chugging clouds of unburnt fuel etc,. I tried the koko procedure and again it hunted and hunted, then finally stalled after a minute or so,. This was about the time that AFI syndrome kicked in for me,. So i've been driving it with the cps disconnected still,. The long crank times are embarrassing,. but it sure runs good,.

Aaargh!!!!

[JohnC]

Could there be a problem with the reluctor wheel, throwing the crank sensor off?

[phantom309]

CRAZY Update: fixed.

I have been picking away at this thing on warmer days,. I reasoned i had a problem with crank position sensor wiring,. I knew i had steady 5v and good ground, so unplugged the signal wire pin at the connector by the thermostat and ran it direct to ecm. Cleared codes,... bupkiss. As soon as it hit 175f back to barely idle clouds of smoke with quick bursts of timing and rpm jump to 900 for half a second. So feeling homicidal and suicidal at the same time, i searched the interwebs again and found a guy had had the identical troubles, all taking place about 3 weeks after a new pmd and resistor was installed. His fuel injection pump guy told him to use his old resistor and it cured the problem. My pmd is on the inner fender on a heat sink, and i've been carrying my pickup pmd next to it, i plugged in pkup pmd, i had already cleared codes, so i initiated koko, then fired it. Well holy faaa* !! It idled smooth, drove fine, i ran some errands today multiple starts ( after 1 turn mebbe!!) no codes! runs like a champ and cruise works now,. I'm so happy i could just,...... well anyway.
So a bad resistor? Pmd?
What is the significance of 175f? Is it from closed to open loop? Is it running on fixed tables till 175? then it verifies resistor value?
How many koko's will the ecm revert to its last known value for a resistor before it needs verification?
Questions i wish i could read up on

[JohnC]

I vote for bad PMD. It's been years, but, IIRC, the ECM only reads the resistor value when you do a TDC offset learn, although there may be some seemingly random set of conditions that causes it as well, but it definitely is not done on any kind of regular basis.

I don't remember if the resistor is isolated from the rest of the PMD circuits, but if it isn't, then a shorted resistor would affect PMD operation.

[More Power]

Too many 6.5 owners have installed a #9 resistor because someone sold it with a PMD kit or they mistakenly thought a #9 would give them more fuel. I wrote an article some years ago about resistor values in an attempt to dispel that myth, but it continues.

Anyone who communicates with me directly will get the response "install a #5 resistor in any new PMD or spare PMD if you don't know what value resistor the original PMD had installed."

We know that some 6.5 systems won't operate correctly with a #9.

[phantom309]

The resistor is a 5,. To be honest i don't know whats in the pkup pmd.
Questions that i have tho,.
Why all good till 175f?
What is significance of 175f?
Why was it over fueling and retarding?

Drove it today, just smiled away! I like this 2wd burb
I will put the big exhaust on it, and the bigger turbo,.and a set of 3:23's

[More Power]

The resistor is a 5,. To be honest i don't know whats in the pkup pmd.
Questions that i have tho,.
Why all good till 175f?
What is significance of 175f?
Why was it over fueling and retarding?

Drove it today, just smiled away! I like this 2wd burb
I will put the big exhaust on it, and the bigger turbo,.and a set of 3:23's

I've never actually tried to watch the stepper motor function when first starting the engine, but I would be interested to know whether the stepper is moving.

I have a number of failed DS4 components that I use for show-n-tell. Among those components is a terribly galled piston that is normally moved by the stepper motor. That part rotates the ring inside the pump, which partially controls timing. A galled/frozen piston will lock the timing in one position - maybe in your situation where it needs to be for a cold start.

P0236 - Turbocharger Boost System: Not an issue for the problem you're describing.

P1214 - Injection Pump Timing Offset: Usually only a problem when a replacement pump has been installed. Performing a Timing Offset procedure corrects it. Can you do this? Not being able to perform a Timing Offset Procedure usually requires a new pump.

[phantom309]

I've never actually tried to watch the stepper motor function when first starting the engine, but I would be interested to know whether the stepper is moving.
P1214 - Injection Pump Timing Offset: Usually only a problem when a replacement pump has been installed. Performing a Timing Offset procedure corrects it. Can you do this? Not being able to perform a Timing Offset Procedure usually requires a new pump.
I haven't done a koko since i did it when i changed pmd's, i'm not sure why you think the stepper is seized, if i unplug the ect it rattles with lots of timing,. In fact that was the first work around i did. When i start it cold(25f here) it rattles hard till it warms a little and the rpm slows,.
troubles would always start at 175f,. As if a switch had been turned on,. If i were to start the engine at 150 it would behave normal till it warmed a little more.
Nobody seems to have an answer as to why 175f is so relevant to a 6.5,.
There is lots of confusion on obd2 in general on 6.5's.

I can remember being told on another forum that i got banned from my 5068 pump wouldn't run with the chip set for 5521,. That was After i had been running it for 6 months,.

So another 6.5 quirk with a wonky resistor unexplaianed.

[More Power]

I haven't done a koko since i did it when i changed pmd's, i'm not sure why you think the stepper is seized, if i unplug the ect it rattles with lots of timing,. In fact that was the first work around i did. When i start it cold(25f here) it rattles hard till it warms a little and the rpm slows,.
troubles would always start at 175f,. As if a switch had been turned on,. If i were to start the engine at 150 it would behave normal till it warmed a little more.
Nobody seems to have an answer as to why 175f is so relevant to a 6.5,.
There is lots of confusion on obd2 in general on 6.5's.

I can remember being told on another forum that i got banned from my 5068 pump wouldn't run with the chip set for 5521,. That was After i had been running it for 6 months,.

So another 6.5 quirk with a wonky resistor unexplaianed.

I didn't say I thought the stepper was seized... I said: "I would be interested to know whether the stepper is moving." The more likely part(s) that would be subject to seizing is/are the "advance piston" and related parts.

The timing stepper motor pulls up on the pivot shaft to advance fuel injection timing.

Why were you banned on another forum?

[phantom309]

Why were you banned on another forum?

Turbine doc and i went a couple of rounds when i posted what my motor put down on the dyno with a converter lockup switch.. Was called a liar, i don't take kindly to that. I was using a chip of unknown origins, with the 5068 pump. Was told it wasn't possible.
Even the dyno printout was questioned Tim was a moderator and didn't like my tone in a pm so i was banned. That was a pm, not a post on the public forum.

[More Power]

Turbine doc and i went a couple of rounds when i posted what my motor put down on the dyno with a converter lockup switch.. Was called a liar, i don't take kindly to that. I was using a chip of unknown origins, with the 5068 pump. Was told it wasn't possible.
Even the dyno printout was questioned Tim was a moderator and didn't like my tone in a pm so i was banned. That was a pm, not a post on the public forum.

Thanks for answering. I always thought Turbine Doc was a good guy.

[phantom309]

Thanks for answering. I always thought Turbine Doc was a good guy.

He is well respected and liked in the 6.5 community, from what i remember he used to roost here then moved to the place then finally truckstop.

All old news

[phantom309]

Performing a Timing Offset procedure corrects it. Can you do this? Not being able to perform a Timing Offset Procedure usually requires a new pump.

Well,.i finally bought enough double double coffee’s that the young guy that owns a local shop hooked his box up to the truck. It’s showing 10.5 deg timing when idling with -1.50 tdco?
But,. When he tried to do tdco procedure it started lumping and smoking like it did before,.so he cancelled and it wemt back to running nice.
I can unplug the ect and you can hear advanced timing,.when it starts cold it rattles for a while. So it is changing its timing,?
You state if it wont do the tdco learn the pump is nfg? Why?
My mileage, with cold weather starts and high idle on, is still 19.2 mpg with 3:73’s and 265-75 tires. I’m happy with things and even if the pump is pooched i’m going to runit till it quits,. Sleeping dogs etc,..

[JohnC]

It's been since 2006, but, isn't it the case that if it stalls during the TDCO procedure the base timing is way off? Try advancing the pump an eighth of an inch and re-running the TDCO set again. -1.5 is a good number, IIRC, but is the number stored last time TDCO set completed successfully, and probably has nothing to do with your current situation.

[phantom309]

It's been since 2006, but, isn't it the case that if it stalls during the TDCO procedure the base timing is way off? Try advancing the pump an eighth of an inch and re-running the TDCO set again. -1.5 is a good number, IIRC, but is the number stored last time TDCO set completed successfully, and probably has nothing to do with your current situation.

2006 john? I’m confused?

The truck did do a succesful koko when i changed pmd’s ,.. and has been running great since. Starts cold well( 1 hole catches up after 4-5 seconds) good on fuel , plenty of power, cruise works😁,. I was just curious to see what it was actually set at, and the guy just tried a tdco learn on his own volition. I almost crapped myself when it started making smoke and running rough!! He cancelled it and i basically said leave it alone thanks very much!! 😳

[Robyn]

If it ain't broke don't screw with it eh

i agree :d:d

[JohnC]

2006 john? I’m confused?

2006 since I owned a 6.5.

If it can't run the TDCO set then I think that means the pump's base timing has shifted outside of the window in which it can operate correctly. This might account for why it won't run right with the sensor connected.

Or, I could be miss remembering...

[DmaxMaverick]

2006 since I owned a 6.5.

If it can't run the TDCO set then I think that means the pump's base timing has shifted outside of the window in which it can operate correctly. This might account for why it won't run right with the sensor connected.

Or, I could be miss remembering...

It's been a while, but that sounds about right. If the timing set is worn, higher than stock TCDO (1.00- or less, IIRC) can cause this, as the timing won't be as stable. Essentially the same to the PCM as a flakey crank sensor. The offset window fluctuates in/out of the acceptable range.

[phantom309]

2006 since I owned a 6.5.

If it can't run the TDCO set then I think that means the pump's base timing has shifted outside of the window in which it can operate correctly. This might account for why it won't run right with the sensor connected.

Or, I could be miss remembering...


CRAZY Update: fixed.

I have been picking away at this thing on warmer days,. I reasoned i had a problem with crank position sensor wiring,. I knew i had steady 5v and good ground, so unplugged the signal wire pin at the connector by the thermostat and ran it direct to ecm. Cleared codes,... bupkiss. As soon as it hit 175f back to barely idle clouds of smoke with quick bursts of timing and rpm jump to 900 for half a second. So feeling homicidal and suicidal at the same time, i searched the interwebs again and found a guy had had the identical troubles, all taking place about 3 weeks after a new pmd and resistor was installed. His fuel injection pump guy told him to use his old resistor and it cured the problem. My pmd is on the inner fender on a heat sink, and i've been carrying my pickup pmd next to it, i plugged in pkup pmd, i had already cleared codes, so i initiated koko, then fired it. Well holy faaa* !! It idled smooth, drove fine, i ran some errands today multiple starts ( after 1 turn mebbe!!) no codes! runs like a champ and cruise works now,. I'm so happy i could just,...... well anyway.
So a bad resistor? Pmd?
What is the significance of 175f? Is it from closed to open loop? Is it running on fixed tables till 175? then it verifies resistor value?
How many koko's will the ecm revert to its last known value for a resistor before it needs verification?
Questions i wish i could read up on

It’s been a long thread,. But it is fixed john, it just wont do tdco.
I have no desire to put a wrench on it. 😁

[Robyn]

If its running good and is reliable then that's all ya need.

Screwing around with it further could open up a can of worms that you simply need to leave tightly closed.

If the check engine lamp is off the computer is happy..

No worries at this time.

I would do the same if it were mine.

Not broke...don':D:Dt fool with it