View Full Version : Injector Pump Timing
I am in the shop right now with a tech II scan tool. I looked at the timing of the injector pump and the numbers read:
5.2
5.3
and -0.26
I am not sure exactly what all this means. But is this good or bad? And is there any advantage to adjusting the TDC to -1.8?
Thanks.
See if you can get a TDC Offset learn at -1.95 or lower.
The Actual Injection Timing should be around 3.5. Though I don't see your 5 being that much of a problem. The pump could be rotated some what towards the Pass. side.
See if you can get the TDC set.
Okay, so when I started looking at the tech II, I got in where I shouldn't have until I was ready. Code 56 was set, and from what I understand I can't do the relearn until all codes are clear. I tried clearing the code with the tech II, but it won't clear. I just now disconnected the batteries, and will see where that gets me.
When I got the truck up to operating temp the numbers read:
4.2
4.1
-0.18
I am not sure exactly how to reset this stuff. Can I relearn the TDC to -1.8 with the pump where it is at? Also, how can I get this code to clear. ALL Data says it is from the PCM not being able to read the resistor (FSD resistor I assume) values.
DTC 56 (almost) always means the resistor is missing. When the FSD is changed, often the resistor goes in the trash (or pond) with it.
You can get a small range of different values when learning the TDC offset, but I'm not clear on the benefit or lack thereof of getting a value other than the "correct" one. Regardless, to go from -.18 to -1.95 you will have to move the pump.
My brother had to replace the FSD about 2 yrs ago. He replaced it with a stock standyne unit in the stock location on the pump. If he had tossed the resistor wouldn't the code have been set before? Also, if the resistor is missing, would anything change other than an SES light/wouldn't it run the same as it did before?
To update the situation, here is exactly what I remember doing today when the code set.
I first checked the timing chain slack by taking the oil filler tube off and rotating the crank while my auto instructor watched the chain. The crank only moved about 1/4" before the chain started to move, so the chain is fine. I installed the oil filler tube, it took a little convincing, but nothing too hard.
Next, I hooked up a tech II scan tool and looked at the engine data display while the engine was running (still no code). I then got into the TDC learn function of the tech II (thinking there was more to relearning the TDC than just going to that specific screen) without going through the proper steps. I also checked out the injector timing screen while I was looking at the TDC learn screen. Next thing I know, the SES lights up. I pulled code 56. I tried erasing the code with the tech II and the tech II wouldn't do it. All the scan tool said is that the code was not erased.
So, then I disconnected the batteries for about 15 minutes. No go. Next, I unplugged the PCM and plugged them back in. I would have unplugged the FSD, but that's a little difficult to get to.
Anyway, this is where I am at. I did not get to do the TDC relearn and now I have a code 56. I talked to my brother and he said all he did was install the stanadyne FSD like he got it. So, as far as there being no resistor, is that possible with a stock stanadyne FSD?
Any ideas or information on what to look at to get this SES light turned off and fixed would be so much appreciated. Thank you guys for all the help so far.
The value of the resistor is stored in the PCM. As long as nothing upsets it, all is well. Commanding TDC offset learn flushes the TDC offset value and the resistor value from the PCM. The code will set on the next start cycle.
The resistor belongs with the pump. A new FSD does not come with a resistor. If you don't transfer it, well, here we are...
The PCM will default to the lowest fuel map so there will be a slight performance hit.
The right way to correct it it to find the old FSD and transfer the resistor. If that's not possible, install a #5 resistor. Some folks recommend a #9, but my experience was it made the engine surge off idle. YMMV.
To install the resistor in the stock location you are probably going to have to remove the intake manifold. It's possible without, but the chance of failure is pretty high, at least for me.
Other options: Go to a remote mount FSD or hack the wiring harness and splice in a resisitor (Not recommended!)
And the 1999 Feature Articles and Product Reviews tells how to set the timing and TDC offset.
My books are greezy :cool:
Thanks for all the help. I will be taking off the intake manifold in about 2 weeks during an engine electrical class to take a look at the FSD. If new FSDs don't come with resistors, then that's my problem. My brother said all he did was take the old one off and install the new one. With it off, I might just order a remount kit and move the FSD.
The "1999 Features Articles and Product Reveiws", is that the 6.5L books? I have both volumes of the 6.5L books. I'll take a look in them. Thanks again for all the help.
If new FSDs don't come with resistors, then that's my problem.
The resistor is tied to the pump, not the FSD. It has nothing to do with the FSD, just an (in)convenient place to mount it.
Right. I just thought that in order to get to it you needed to pull off the intake, and since I had it off, I could pull the FSD and remount it. But I might just leave it on the pump, haven't decided yet.
But, if it is possible to install a resistor without removing the intake that would be awesome.
But, if it is possible to install a resistor without removing the intake that would be awesome.
The resistor is inside the molded connector on the FSD. If the FSD is not mounted on the pump, it's easy. If you bought a relocation kit and FSD, it would be easy. Otherwise I wouldn't even try. Too easy to damage the pins on the FSD.
Yeah, the FSD is still in the stock location, that is why I am going to take the manifold off.
Thanks again for all the help and information.
DmaxMaverick
04-10-2008, 09:39
Have a look at THIS PAGE (http://www.thedieselpage.com/members/tt99-9.htm) for more info on the DS4, PMD and resistor.
Thanks. That article helped.
Now as far as rotating the IP. Do I really need the special tool? I might be able to get a loaner from the local GM dealer through the college I am attending. But if I can't get one, can I rotate the IP without it, or is it not recommended?
The tool allows you to keep the nuts snug and still be able to move the pump and judge the degree of movement. Otherwise you have to loosen the nuts a lot more and the pump can slip back due to the "springiness" of the lines, making it difficult to make precise changes.
As I think it was previously mentioned, do NOT use the shutoff solenoid as a convient handle to move the pump.
Okay,
I haven't installed a new resistor on my FSD/pump yet (going to this next saturday) and wanted to know if the truck will run fine on the highway with code 56 still lit up?
I am probably going to buy a Mac tool chest and need to go pick it up about 4 hrs away. Will my truck run fine on the highway with code 56 still on? Quick replys much appreciated. Thanks!!!
DmaxMaverick
04-25-2008, 19:22
There will be no problem running it with a DTC 56. It may have slightly less maximum power output, but no damage will occur.
Thanks. That's reassuring.
So I finally installed a #5 resistor from Kennedy Diesel last Friday. Everything seems to run fine. When I first started the truck, the SES light immediately went out!!! I was going to do the timing again on Tuesday but was a little hesitant, with what happened last time. Okay, so here is my question. What real advantages do I have to change the timing on the pump? The chain is a little stretched, but seems to be within specs. I drove the truck two weekends ago down to Salt Lake City, UT and the truck got about 18 mpg. With this kind of mileage, is there any advantage to changing the timing?
Again, I appreciate all your answers and help, I am still learning here.
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions Inc. All rights reserved.