pump tdc offset question

[DmaxMaverick]

-1.41 is fine. Some engines aren't able to reliably set -1.94, often due to a sloppy valve train. Easy to get with a gear set or new timing set, and/or new pump, not so much with worn chain/sprockets or a well-used pump.

[omoige]

DmaxMaverick, your response is a breath of fresh air, so relaxing. Thanks so much. I am almost tearing off my hair.

I am still having black smoke though. Will this clear away with time now that I am somewhat close to the engine running perfectly. I mean, the engine is so smooth running I could drive with my coffee mug on the hood without spilling it. so far, running at idle without smoke, but when I step on it, it puffs smoke, though not as bad as when I started out when it was -2.46 TDC

[DmaxMaverick]

A puff of black smoke on hard acceleration is normal. The 6.5L fuel delivery, unlike later Diesel engine designs (Duramax, etc.) are not dependent on air volume. If the smoke continues after the turbo spools up, you may need to look a bit closer at that end of it. A fouled air cleaner will also cause the same thing.

[Kennedy]

Once you are close you can keep on initiating the process until it hits on your number. To get to -1.94 you'll need a c-hair of a nudge though.

You're OK where you are though too.

[omoige]

Thanks a lot Kennedy. I am just going to leave it here since you guys, in you prowess of knowledge, have assured me that this is just fine. It took me endless trials to get to this point.

All the same, I will try using the Tech 2 to keep trying to relearn to see if I can get lucky to get it there. I am so grateful for your contributions here. I wouldn't know what to do not for this forum.

[omoige]

Once you are close you can keep on initiating the process until it hits on your number. To get to -1.94 you'll need a c-hair of a nudge though.

Hey what do you know. I kept re-initiating the re learn process. I am now at -1.58.
Please guys, explain something to me. When I am driving this hummer, usually go about 60 miles average, the temperature is always on the third quarter borderline line. That is the next after the middle line. However, once I either slow down or standing still, idling, it goes down to just a notch to the other side of the middle line. Since there is no number on this temperature gauge like my Japanese cars, I am not sure if this is ok or running hot. Please educate me.

[DmaxMaverick]

Hey what do you know. I kept re-initiating the re learn process. I am now at -1.58.
Please guys, explain something to me. When I am driving this hummer, usually go about 60 miles average, the temperature is always on the third quarter borderline line. That is the next after the middle line. However, once I either slow down or standing still, idling, it goes down to just a notch to the other side of the middle line. Since there is no number on this temperature gauge like my Japanese cars, I am not sure if this is ok or running hot. Please educate me.

It's hard to say. In order for a gage to be accurate, it must use the sender it was originally designed to be paired with, and it has to be accurate to whatever standard accepted at the time. Having numbers on a gage will not make it any more accurate than a gage without, unless you know what the needle positions actually mean, and many aren't even linear, or are only accurate within a very specific range. Ford's historical H-C gage is actually better in this regard, in that it only indicates an operating range, and not some obscure number that means nothing to the vast majority of the population. Ultimately, instrumentation is only effective for tracking trends. Once you know what is hot enough, and not too hot, you only need to watch that it doesn't exceed those limits. The same applies to any other instrumentation.

Solution....
Install a new mechanical temp gage and watch it, and compare it to the OEM gage. Anything less will tell you nothing more than you already know.

[omoige]

[QUOTE=
Solution....
Install a new mechanical temp gage and watch it, and compare it to the OEM gage. Anything less will tell you nothing more than you already know.[/QUOTE]



That's a great idea. I never thought of that. I will shop around to get a VERY good mechanical gauge and see how it differs. However, because this is my first diesel truck, and a a hummer H1 for that matter, I have no idea what is the normal operating range on this needle style gauge. If I have to relate it to my Toyota FJ Cruiser or my Porsche Cayenne S for instance, it is already over-heating. What gave me peace of mind was the last time that I connected my Tech 2 after just coming back from one a hell of a grueling ride in the jungles. While I was thinking that the engine has seen some serious abuse, the Tech 2 reported that my temperature was too low to do a relearn. I have driven this car for the past 5 hours through grueling coastal jungle and I thought I have overheated it at some point. Anyways, I am learning as I am going along. And with all the experienced hands in this forum, I have GREAT mentors to fall back on. I am beginning to like the sound produced by my diesel too.

[DmaxMaverick]

You don't need to know, yet, what the normal operating range is for that gage. That is what the mechanical gage will tell you. You will also need to know what temp the thermostat is, to determine if it is doing its job. Replace it with new, if you don't know. Get a new stat from the dealership (Delco ONLY), or from Kennedy. Any others are substandard junk that won't work if you work your truck hard. To round off the equation, you'll also need to know if the fan clutch is engaging, and holding, when it should. A lazy fan clutch will make all your efforts moot, having no way to manage high load temps. Your Hummer H1 may have a hydraulic fan clutch, which allows for much more flexibility. If not, installing one would be a significant upgrade.

[omoige]

Hmmm, must have done something wrong. I just ordered new set of thermostats from Rock Auto. They should be arriving in a day or two. They are the Motorad brand. My Hummer uses 2 in a row. Do I have to return them? For the fan clutch, when the engine temp gets up, I know it works because the sound changes to something heavier from under the hood. And as soon as the temp goes down, it goes quieter.

Also, I noticed something that is rather strange (to me, of course)earlier today when I was cleaning the engine. I removed the PSD with the #9 resistor and put one without the resistor. I started the engine. At first it was running great, then suddenly, it started to accelerate weirdly up and down. Then I put the old one with the resistor back. Everything went back to normal. Then I removed the resistor from the old one and connected it back, it started running weird again. As soon as I inserted the resistor back and connected it, everything went back to smooth idling. Is this normal? Does that mean it must have the resistor to run? Or is this resulting from the relearn process I initiated, because I did the relearn with the resistor in the PSD. PLEASE educate me.

[DmaxMaverick]

The resistor is necessary, or the PCM will have a fit. The #9 may be your problem, as some PCM's don't like it, or don't like it in combination with your pump, more appropriately. The resistor is a "calibration resistor", which does nothing more than communicate to the PCM the calibration range of the pump, and some are out of range with a #9. In any case, increasing the resistor number can increase power, but you'd really need a dyno to notice it. It isn't like turbo boost on KITT. I'd be very surprised if you were able to do a TDCO learn with it removed. The Sol-D is the only FSD I know of that doesn't require a resistor, and they aren't common lately.

The dual thermostat is an excellent option, and probably not part of any of your problems if they are working. The pair you got from RA is probably OK, if they're the correct temp (2x 195, or 195 + 205), lower is not better, if the rest of the system is healthy, but the high capacity water pump is necessary to take full advantage of it. Cooler stats doesn't do anything but lower your threshold, and won't allow for more loading. Just something to keep in mind. The cycling fan clutch is good, as it indicates it's active when it should be. The stat(s) control when the fan clutch engages, most people don't know that. The hydraulic clutch, if you have one, or a Kennedy clutch is ideal, as they engage more positively (aggressive), when they are engaged.

[omoige]

The resistor is necessary, or the PCM will have a fit. The #9 may be your problem, as some PCM's don't like it, or don't like it in combination with your pump, more appropriately.

Now I get it!! I am on my 3rd FSD. The truck came with the Standard FSD. Because the car was running rough, I bought a used Stanadyne PMD. It didn't help the situation. They I bought the brand new grey Stanadyne with all the relocation kit. That one came with the #9 resistor. He gave me the option of either #5 or #9 when I was buying it after I explained my problems. As soon as I installed, it was running great. Then the code P1214 came up. But since I cleared the codes with helps from this forum, I have been having fun as the car has been a great runner with the exception of trying to get it on the -1.94 dot. Should I change the resistor to #5 then?

The dual thermostat is an excellent option, and probably not part of any of your problems if they are working. The pair you got from RA is probably OK, if they're the correct temp (2x 195, or 195 + 205), lower is not better, if the rest of the system is healthy, but the high capacity water pump is necessary to take full advantage of it. Cooler stats doesn't do anything but lower your threshold, and won't allow for more loading. Just something to keep in mind.

Dmax, please elaborate on 2 points you raised for me here. You wrote that "lower is not better" I may be wrong, I usually think that lower means lower operating temperature. Have I been wrong all the while? By the way, stats I ordered are both 195s. Secondly, How do I know if my truck has the high capacity pump? Doesn't this model come with it anyway, since the 2 thermostats are factory installed to correct overheating problem from previous models. Thanks again for your responses. They are really educating me.

[DmaxMaverick]

Now I get it!! I am on my 3rd FSD. The truck came with the Standard FSD. Because the car was running rough, I bought a used Stanadyne PMD. It didn't help the situation. They I bought the brand new grey Stanadyne with all the relocation kit. That one came with the #9 resistor. He gave me the option of either #5 or #9 when I was buying it after I explained my problems. As soon as I installed, it was running great. Then the code P1214 came up. But since I cleared the codes with helps from this forum, I have been having fun as the car has been a great runner with the exception of trying to get it on the -1.94 dot. Should I change the resistor to #5 then?

The P1214 isn't related to the resistor. Just a note, but the resistor is located in the PMD connector for no reason other than convenience. It has nothing to do with the PMD. Stanadyne put it there, apparently, because it was just as good a place as any. The purpose of the "calibration resistor" is to compensate for slight variations from pump to pump. The PCM only reads (checks) the resistor periodically, so if it's one it doesn't like, or is missing, it may be several warmup cycles before it actually notices. P1214 is the PCM complaining that it can't compensate the TDCO, because the pump is out of physical range (in your case), or some other reason. Even if you manage to get it at -1.94, the PCM may fault at a later time due to valve train variations (sloppiness), usually more common on higher mileage engines.

Dmax, please elaborate on 2 points you raised for me here. You wrote that "lower is not better" I may be wrong, I usually think that lower means lower operating temperature. Have I been wrong all the while? By the way, stats I ordered are both 195s. Secondly, How do I know if my truck has the high capacity pump? Doesn't this model come with it anyway, since the 2 thermostats are factory installed to correct overheating problem from previous models. Thanks again for your responses. They are really educating me.

Lower is not better, in that, a reduced operating temp (below OEM) is not, necessarily, better.
If your engine is stock with the dual stats, it will (should) have the high volume water pump. A pair of 195 stats is good. A lower operating temp is not good, as it reduces combustion quality, and metallurgic variations are less consistent. The only reason to lower the operating temp, by any means, is to compensate for an inadequate cooling system. If your system is healthy and able to manage high load temp ranges, higher is better. Most cooling systems are very good when new, not so much as age and miles add up. Unfortunately most of the time, engineers don't design too far down the road. Regular maintenance is the key to keeping a system healthy.

[omoige]

I am glad I discovered this forum. I am a great example of how what you don't know can hurt you. I was already thinking on researching how to get the 6.5L Turbo Diesel engine in my H1 to run cooler.

Thanks for all these priceless information.

[DmaxMaverick]

I am glad I discovered this forum. I am a great example of how what you don't know can hurt you. I was already thinking on researching how to get the 6.5L Turbo Diesel engine in my H1 to run cooler.

Thanks for all these priceless information.

Well, there are several schools on this. A reason to want to reduce the operating temp, as I said before, is an inadequate system. A system inadequate for any number of reasons, including old, failing and in need of significant repair, or added load on an already marginal system. The solutions are simple, although often not inexpensive: Repair/replace as necessary; or increase cooling capacity and/or efficiency. If you aren't having uncontrollable overheat issues, what's to worry? If it ain't broke, don't fix it.

[omoige]

If you aren't having uncontrollable overheat issues, what's to worry? If it ain't broke, don't fix it.

You got that right buddy. Truck has only 66,000 miles on the odometer and runs like a champ. I'll just keep it that way for now. Once I learnt more tricks from guys like you in this forum, I may stat to alter things.