Tuning - tweaking "timing adder" to lower cold start smoke?
 

From my research, there is a SOI "timing adder" that modifies the SOI timing table when the oil temp is cold (possibly only on manual tranny models, but I'm not positive on that). In another forum, I found an older thread advising to lower the timing adder by 10-15% to alleviate cold start smoke on manual transmission models with modified injectors. The poster noted that he had lowered his by 35%. Does anyone have experience with this from a tuning perspective?

Please do not make the typical glow plug/GPR suggestions. Plugs ohm fine, wiring harness ohms fine, GPR (new Stancor) operates as designed, UVCH pins are perfect with no signs of burns/arcs.

Are you sure the glow plugs are working?


















Sorry, I just couldn't resist :)

Pikachu - go play in your ice storm. :-X04

Unless you have minotaur, this is all conversation.

Just going to ACs already bumped your SOI by default, unless your tuner retarded the SOI a little too much for a cold start. If this is the case, start the truck in stock mode and see what that does. If I can drive 400 miles on a stock tune with 100% nozzles on ACs and be fine, you can idle in the driveway with an obnoxious-rompmobile. I put the truck in Drive as soon as it started... to put a load on it, and this avoided the romps. I don't know what you'll do, other than just drive off and watch the tail pipe.

Rich, I have my ways...}>

I'm on the Swamps 175 singles, so no-go on the stock hybrid program - idles like a Harley.

There are two variables that need tweaking - the timing adder, and the offset. It'd just be real handy if someone had some values to throw out there to try.

I think you're referring to the thread at PSA...hazing at idle. I think you'd be better served asking there.

...but does it smoke?

Steve, you have the Hydra correct? Why don't you try a different tune? I believe Bill ((PHP) will e-mail you one for @ $25.

There are two maps (tables) that adjust timing based on oil temps. One looks at oil temps and engine RPM's, the other looks at oil temps and ICP. Then there's a few functions that also tweak timing slightly based on oil temps. All of these are the same regardless of transmission.

Not sure what Jonathan has adjusted on your tunes. I used to have a set of his tunes for those injectors a few years back, but I lost them when my old laptop crashed. Besides those tunes were so old I'm sure he's made quite a few changes since then.

Steve,

As you know, I'm running the same injectors. Here is a pic immediately after startup at O'dark-thirty this morning (26 degrees OAT, not plugged in & parked outside overnight) - Haven't used the truck in 10 days - but now that the snow is melting it's time to take the 2WD out...... no smoke or haze. I believe I know the thread you are talking about - but didn't that apply to the early 99 models? What PCM code do you have in the truck?

Pocket - could altitude also be playing a part in this? IIRC Steve is at @ 5,000 ft.

Nothing at all against Johnathan or Swamps - but for $25 I'd be tempted to try a different tune just to rule it out of the equation.....

Have you ever replaced your EBP sensor?


http://i304.photobucket.com/albums/n...ps145820a8.jpg

Rich, I may reach out to Bill just to give it a try - easy enough. As for the EBP sensor, I've never touched it. Though I've done quite a bit of looking and can't find an answer to the question, if I've deleted the EBPV (new outlet, blank pedestal), does the EBP sensor serve any purpose? I know it affects shift points for an auto, but that doesn't apply. I know everyone's first instinct is to say, "Well of course it smokes a lot, you took the EBPV out," but that's not causing this much smoke. I've definitely got more fuel than I'm burning at startup. I haven't checked the ICP connector for oil - I'll take a look at that as well. Finally, well, I think it's time for the AE purchase. I'm keeping this truck for the long haul, so AE will no doubt prove helpful in the future too.

I'll chime in later when I get home (others will surely as well) but I deleted the EBPV in mine also. The EBP sensor is a totally different & separate animal. Not sure if it's related to your issue. But if it's clogged it can really throw fuel economy off. You need it and you need it to function properly.


Edit : the pick I posted was with running one of Tony's tow tunes.

In my opinion - the sooner you get AE the better. I purchased mine about 8 years ago and have used it on my two 7.3L's and about 20 others. It gets used alot and makes troubleshooting a whole lot easier.

As far as the EBP sensor goes you need to remove the tube and sensor to clean it. But you also need a scanner like AE to monitor the EBP sensor, MAP and ambient pressure sensors to see if the sensors are reading correctly. Unless the sensor outright fails you wont get a check engine light or a code.

Occasionally the sensor and tube get clogged with soot because it is measuring exhaust back pressure. Some replace the tube and others just clean it out with some WD-40 and some weed trimmer string hooked up to a drill. Occasionally some have a tube that has rusted out all together.

It's only a 10 minute job to pull the tube & sensor off a cold engine.

Is this causing your haze/smoke problem? I don't know. But it is one of those items many folks have on there yearly maintenance schedule to check and it could give you some headaches and lousy fuel mileage when not functioning properly.

Along with checking your ICP and as well. It is so much easier to troubleshoot other areas when you have all the base items working & functioning correctly.

Any word on the culprit Steve? Did you replace the MAP sensor?

To bring everyone else up to speed, I've chatted with both Rich and Rich after I got my AE package. My MAP sensor is bad, reading 10.7psi on a cold engine, KOEO, while the EBP and BARO both show the proper 12.3psi for my 4800' altitude.

The new MAP sensor is one the way, and I'll drop it in next Monday and see what the difference is.

I reached out to 2000ca250, who did a lot of research on single shots and cold start smoke a couple of years ago on the PSA forum. He gave a few pointers, but we're going to hold off on tuning changes until the good MAP sensor is in place.

The MAP may have an effect on cold start smoke. According to Dieselcare's site: "The PCM monitors manifold pressure to control fuel delivery in
order to minimize smoke. It also optimizes injection timing for detected boost. It also monitor boost to limit fuel delivery to control maximum turbo boost."

Now, at cold start, there will be zero boost. With the current sensor, MAP - BARO = 10.7psi - 12.3psi = -1.6psi. I'm not sure if this would throw the PCM at all, or if the PCM would take that reading to 0. This should be the calculated MGP (manifold gauge pressure), so I was going to head out this morning and pull MGP using AE.

I'm heading into the shop on 4/12 to drop in the new clutch. I'm going to pull the valve covers while I'm there and double-check tightness of the injector bolts. I doubt that's a factor though, as the morning after injector install, I had the cold start smoke. But I've also read about Rich (Tugly's) woes with loosening injector bolts.