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I just don't get it.

I

imadtchmn

imadtchmn
Messages
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Location
Macon, GA
I did a koko reset on the ecm. No other changes. Now it runs rough, pedal is touchy. If I push through it to 1500 rpm is runs fine from there up to 3000 rpms. Anyone else experience this kind of thing? Does a koko clearing also require a reflash? This just is not making any sense. I'm at the point of selling this thing. Parts are not only hard to find, but expensive to purchase, even used.

99 chevy c3500 6.5
remote pmd
apps replaced (had an accident with it)
no codes
 
Remote PMD?

Not trying to insult you, but it does have the resistor installed, yes?

Is it an old or new PMD?

It's also possible the TDCO value stored in your PCM was not correct before you did the KOKO. If you do a KOKO relearn and the IP is not where the PCM thinks it is, it learns the current value and will store that new value. If that new value is out of limits, it will run poor.

Here's a little personal experience with it:

My truck had a TDCO value stored when I bought it (duh). Truck ran great.

I did a KOKO relearn and it ran like crap. The thing idled rough and had no power/missing on throttle application. I bought car code (scanner) and my TDCO was out to lunch. Way out.

I retimed the IP and ran another relearn. TDCO value was now back to within specs.

Truck ran great again.

For some reason, these beasts will run fine with an IP that's "out of whack" if the TDCO value is within limits. As soon as you "teach" the PCM where the IP actually is, it stores the new value and it run poorly.

Does this mean you shouldn't do a relearn if it's running well?

Well, no. The IP needs to be timed right first. Running on an old TDCO value just masks the problem and it's not running right even if it "feels" like its right.

Your problem could very well be something like a bad extention harness or another small issue, but if all you did was a KOKO relearn I'm betting your IP is out of adjustment just enough for poor running....
 
Now that makes sense. Yes the resistor is installed. I was wondering about the TDCO value. If I would have known that it cleared the old TDCO value, I would have never done it. Now comes the timing part. Since I don't have any scanner, it will be a trial and error thing, at least till I can get it somewhere to have it timed correctly.

I really appreciate the information. Sure clears things up and saves me from buying any unnecessary parts.
 
As long as you have a code reader, you could see the code is for TDCO, move the IP, clear the code, do KOKO and if the code doesnt come back I guess you are good. I explained this process is an another thread recently and about where the IP should be installed in relation to the timing mark.

The same goes with the resistor value, it is updated during TDCO learn.
 
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imadtchmn said:
Now that makes sense. Yes the resistor is installed. I was wondering about the TDCO value. If I would have known that it cleared the old TDCO value, I would have never done it. Now comes the timing part. Since I don't have any scanner, it will be a trial and error thing, at least till I can get it somewhere to have it timed correctly.

I really appreciate the information. Sure clears things up and saves me from buying any unnecessary parts.
Click to expand...

Well, the thing is if you ran a relearn and the Tdco value is "out of limits" you ip need to be adjusted anyways.

Try setting the ip "straight up" and run the KOKO relearn. That may be close enough to get you running right.

IOW, the fuel shut off solenoid (round silver thing) should be completely vertical. Then it's trial and error rotating the pump left or right.

You also are supposed to need to clear any active codes for the relearn. I've never tried it with an active code, so I can't confirm or deny that.

Be very careful moving the pump. As little movement as 2mm can be too much.

A scanner that does 6.5 obdii makes it easier as you can check "time set" to know if that's correct and then it is useful checking Tdco in so much as you will know which way to rotate the pump.

I use "car code". Not really user friendly but easy enough once you learn it. It also will do a lot of built in tests and enhanced gm obdII codes.

And it only cost me 60 bucks. I could have built my own interface and software, but it would have been waaaaaay more hassle than forking over the 60 bucks and learning the pre-existing car code software.

Here's hoping Tdco is your problem. Takes a bit of time and fiddling to get it right, but its an easy fix (ie:cheap)

:)
 
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With OBD-II if resistor is missing it won't start as it was running on stored value, you should see a P01218 code as well if that is the case. If you did a TDCO and IP had been moved your PCM is seeing current location of the IP which depending how far it was moved may or may not cause a other related timing code just crappy operation/starting.

Call around many independent shops may have an old MT2500 around which was a common scanner back in the day, if you find one of those even we can walk you through a retiming.

BJ you are correct if there is a stored code in the PCM you won't be able to do the relearn,

DTCHMN also when doing time/TDCO relearn engine temp has to be > 170F; also do not try to move the IP with the shut off solenoid (silver thingy) you can snap it off or damage it
 
Turbine Doc said:
...BJ you are correct if there is a stored code in the PCM you won't be able to do the relearn...
Click to expand...

Figured as much.

I usually save the history and then clear the PCM when doing this stuff as a matter of course.

Always have, just seems the way to go.

I clean the history so I can see what the changes do to the PCM and nothing else......
 
Took a look at the position of the ip this morning and it seems to be angled to the drivers side a bit. I'll reset it to vertical sometime this morning and see how it goes. I think someone may have moved it at one point. Nothing like learning things you never knew before. Since I tow a 5th wheel, this would explain a lot about losing power pulling hills. I will also be changing the resistor value from 5 to 7 but will wait with that until I get the timing correct, then do a koko for the new resistor.

Great White, your description of the trouble you had on a koko relearn was invaluable. That is exactly the issue I had. BTW I did get the car care software and hopefully it will work with the adapter I borrowed from a friend. Its a klm 327 adapter. So today we attack the IP. :)

I'll post, hopefully later today, on how things are going. Now the title needs to be changed to "Now I get it" ;)
 
imadtchmn said:
Took a look at the position of the ip this morning and it seems to be angled to the drivers side a bit. I'll reset it to vertical sometime this morning and see how it goes. I think someone may have moved it at one point. Nothing like learning things you never knew before. Since I tow a 5th wheel, this would explain a lot about losing power pulling hills. I will also be changing the resistor value from 5 to 7 but will wait with that until I get the timing correct, then do a koko for the new resistor.

Great White, your description of the trouble you had on a koko relearn was invaluable. That is exactly the issue I had. BTW I did get the car care software and hopefully it will work with the adapter I borrowed from a friend. Its a klm 327 adapter. So today we attack the IP. :)

I'll post, hopefully later today, on how things are going. Now the title needs to be changed to "Now I get it" ;)
Click to expand...

Unfortunately, Car Code won't work with an elm327 interface. I've tried with a couple elm 327 interfaces myself. It needs it's proprietary cable. That cable does give you "two way" communication with the PCM though (IE: intiating tests). You can give it a try, but i'm skeptical that it will work. That's why the software is "free" to download; you have to buy the cable to get it to work.

An elm 327 interface will let you read and clear codes though. But you need the software to read the data stream (laptop scanner program).

There are a few free bits of scanner software on the net. Here is a link to some free and "not free" OBDII stuff that works with an ELM327 interface: http://www.obd2allinone.com/sc/pages.asp?pageid=60

I don't think any of the free stuff there will do tdco for you, but some will capture freeze frame data and clear trouble codes with a ELM327.

Reading the Time Set and TDCO is another story. You need a program that will allow you to create a custom PID, or one (like car code with the cable) that already has it defined.

All you need to really do is get the IP in the right position and do the relearn. You can do this by trial and error by tweaking the pump slightly. It could take a while this way and you won't know if the pump is advanced or retarded or what the time set and TDCO values are.

It relearns the resistor when you fire off a relearn anyways.

You can get it running acceptably for daily driving this way with a little time and care with "trial and error".

Keep in mind, this is all if the TDCO value is your problem. If you have a mechanical or electrical gremlin hiding in there and causing the rough running, all bets are off.....
 
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IT LIVES, and yes I'm yelling that. :) I found out what the issues were. 1. Timing was way off. Almost 3 degrees at that. Reset the timing and did a koko. Wouldn't start. Hmmmm. 2 Rechecked the connections to the remote pdm. Yup, there was the second problem. One of the pins in the pdm was bent up and looked really bad. Wasn't making any kind of connection at all. Not sure how it even ran before. Fixed the pin, reconnected carefully and guess what happened then. It started and ran great. I'll be picking up another pdm sometime in the near future.

I want to thank everyone that posted here and sent me pm's to try and figure this truck out and the patience that you all have with newbies, unlike another forum I tried to get help at. I may even keep it now. Well at least until I can afford one with more power. Now maybe I can help someone else with the knowledge I have acquired here.

You all should be proud of yourselves for having a terrific forum. Thank you.
 
Aaaannnnnddddd.............................................the hook is set!

Enjoy the addiction.


Glad it all worked out.

Good find on the bent pin.

Those little things wrong are always a biotch to track down and will drive you crazy.....

:)
 
great white said:
I use "car code". Not really user friendly but easy enough once you learn it. It also will do a lot of built in tests and enhanced gm obdII codes.

And it only cost me 60 bucks. I could have built my own interface and software, but it would have been waaaaaay more hassle than forking over the 60 bucks and learning the pre-existing car code software.

Here's hoping Tdco is your problem. Takes a bit of time and fiddling to get it right, but its an easy fix (ie:cheap)

:)
Click to expand...

Great White,

Where did you find "Care Code" for only $60? I have neen looking at getting it, but the price with cable was arond $150.

Thank
 
1629dill said:
Great White,

Where did you find "Care Code" for only $60? I have neen looking at getting it, but the price with cable was arond $150.

Thank
Click to expand...

It was an ebay sale.

Same guy as the web site.

I just don't have one that does CAN. Not a big deal, I've got other ways of reading CAN bus vehicles for "customers"....

My car code software is for personal use on the 6.5 only so I'm good with it.
 
imadtchmn said:
I want to thank everyone that posted here and sent me pm's to try and figure this truck out and the patience that you all have with newbies, unlike another forum I tried to get help at. I may even keep it nowGood plan. Well at least until I can afford one with more powerBad plan :). Now maybe I can help someone else with the knowledge I have acquired here.

You all should be proud of yourselves for having a terrific forum. Thank you.
Click to expand...

Our pleasure sir and it is why we are here to help out others, some get frustrated with our insistence to drill down to cause with simple things like did you check gnds-wires-etc. rather than postulating a quick "It is X".

Reason is many of us are 6.5 owners by choice with been there done it/hated it/fixed it/still love em in spite of their problems experience, that decided to stick with our "Jurassic Park" dinosaurs when others "went the way of dark forces" :) modern common rail Diesel.

Nothing wrong with CRD that is where the "BIG power" is; I'll succumb to the need/availability one day, but until then I'll just keep having fun with these "old ones" because I like old, especially since I resemble old myself :eek: .

Maybe that is difference with site age of the group not caught up so much in being bad-ass like the 20 somethings forums with their teens in the mix as well.

FWIW you have found THE SITE for 6.5 information be sure to invite your friends.

In addition to the venerable 6.2/6.5 family we are pretty proud of our other forum haunts; Dmax-Cummins-Stroke etc. same level of maturity IMO and some smart tech. guys there as wel;l with mucho been there done that experience.

This site grew out of a need to sort out the posturing BS of other sites, TTS is an extended family of sorts it won't take long for you to figure that out either.

Ditto on BJs "Hook it set ..............!"

When I started in 2000 with mine, I was poster child for the claim "6.5s don't have any balls" not in as delivered trim, well it is a much different beast now.

Wishing you continued success/good luck with your venture, we can get you through whatever ills and problems you inherited from prior owners that did not know how to properly feed & care for the 6.5.
 
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