ORM and cold starts

DnA Diesel · **Posted:** Thu Jan 03, 2008 3:37 pm

brew1 wrote:

DnA Diesel wrote:

nix wrote:

My CRD w/o the ORM (so, my MAF is still plugged in) takes like 5 cycles normally to start in this sub 30 degree weather. Isn't this normal for a diesel in cold weather?

Not for the VMM R428. It should flash up in one glow cycle (~3-4 sec) and about 2 secs of cranking, and as UFO says, it smooths right out after a few seconds. The common rail injection makes a big difference. -15*C/5*F today and not a problem. My VW TDI will sometimes take two or three cycles of the glow plugs, but it still flashes up after just a bit longer cranking than the CRD.

Funny, my 2003 Jetta TDI starts right up, whereas the wife's 2005 CRD takes a bit more cranking time.

Brew, just found my problem on the TDI...GP's resistance (#1/2/3/4 resp.) 0.7 / 0.8 / 5.6M / 0.7 ohms...oooops! Just tucked by the stealer to get a $55 replacement GP...starts on the first cycle now. All is well in diesel land.

p.s. FWIW, I think I'm one of the few not running the ORM, re: cold startability.

Cheers,
Duey

panda-52 · **Posted:** Thu Jan 03, 2008 4:31 pm

I have been running with the ORM for at least the last 8,000 miles. Within the last month (before this thread appeared) I've begun to notice that the CRD requires more cranking than I remember last winter. I would guess 3-4 seconds on the first cycle during cold weather. But only after sitting for a long time, like over night. At first I suspected air in the fuel but when I pumped and bled, I got no air. I then checked codes and there were no unexpected (GP) codes. I suspected faultly memory (mine) and not the ORM. What makes it really noticeable is that I also have a 2002 VW TDI that starts almost immediately even in the coldest weather.

Maybe there is something to this.

weantright · **Posted:** Fri Jan 04, 2008 11:40 am

BlackLibertyCRD wrote:

check for white/gray smoke when starting and stronger than normal diesel smell. Was the engine fully warmed up when shutting off? Check how long the engine takes to warm up with and without the ORM.

Yes it blows white/gray smoke with strong Diesel smell when this hard start happens using ORM. ORM off, starts with one little puff of grey smoke. More descriptive on start up, cranking 5 seconds with no, not even a pop to start,,, cycle key and repeat. Do this 3-5 times and it will start. As for air in fuel/rail, I bleed air at filter once a week but no change to ORM and hard starting. I know this winter blend fuel sucks as my Powerstroke smokes like crazy at start-up and this never happen last year pre-ULSD. My fuel supplier has 2% soy bean bio and has a green tint to it. Washing the truck's exhaust pipe and green crap came out. I will be trying a different fuel supplier to see if the Powerstroke starts hotter and less smoke.

CRD is completely warm at shutdown (45 mile trip home from work). One more thing, if it starts I can shut it down right after and it roars to life on one cycle. Warm-up seems to be the same with or without ORM, haven't notice much different eitherway.

BlackLibertyCRD · **Posted:** Fri Jan 04, 2008 12:31 pm

Good idea to try differnet fuel supplier. I would run most of the fuel out before refilling. I only have problem such as smoke only when not letting it fully warm up before shutting engine off. I could use the grill cover if it was much colder here.

chadhargis · **Posted:** Fri Jan 04, 2008 12:59 pm

Mine used to be really hard to start when it was cold, but I just had my filter head replaced and it was 18 degres yesterday and 25 degrees this morning. I had to crank it a little longer, but I'd say after about 3 seconds it fired up.

Before I had the fuel head replaced, it would smoke badly, but now it doesn't. No really strong odor either.

I have been running the ORM for about 10,000 miles.

retmil46 · **Posted:** Fri Jan 04, 2008 1:12 pm

Got back home last night from TX. Coming back up thru Arkansas and TN, it didn't even make it into the mid 30's during the day, and into the low 20's and teens at night. Yesterday morning in Forrest City Arkansas, it was 18 F - even with the ORM, fired right up on the first try. Scanguage showed 30 F coolant temp and 31 F air intake temp after it was running.

This beast DOES NOT like cold fuel. On the first leg of my return trip up into Arkansas, the fuel mileage absolutely sucked. I stopped in Greenville TX and did a field swap on the fuel filters, as I knew before the trip they'd already caught quite a bit of crud, but that only bumped it up to 25 mpg at best, and fuel pressure downstream of the filters was a full psi low even with clean filters.

When I pulled into the motel in Arkansas, I checked the filters before shutting it off - they were cold to the touch, as was the aux tranny cooler. After seeing what the outside temp was, I could have kicked myself in the butt - everything was getting supercooled.

Next morning, dug out the cardboard and tystraps, and crawled underneath to cover over the fuel cooler and aux tranny cooler. That did the trick. Fuel mileage shot back up once the tank warmed up some, and when I pulled in about 180 miles down the road for my final fill-up, the filters were at least somewhat warm and fuel pressure was up to a full 4 psi.

Mileage dropped off somewhat later when the sun went down and temps dropped back into the 20's and teens, but still managed to pull 500 miles out of that last tank and pull into the driveway with 1/8 tank left.

I'm just glad that as a rule when I make this now-yearly trip, I always put in 16 oz of PS White, and this time 16 oz of 2 stroke oil, on every tank.

bentrod · **Posted:** Fri Jan 04, 2008 1:25 pm

What mine has done from day one is:
Starts up fast from about 55 degrees and up.
Starts like crap, a few key starts-stalls, from 55 down to 30 degrees. White smoke too.
BUT when its colder then 30 it fires right up fast (but with a loud "nailing" sound for 2-3 seconds)
This is one strange duck!

weantright · **Posted:** Fri Jan 04, 2008 2:28 pm

Retmil where is the fuel cooler? Easy to see from underneath? What did you cover it with? Do you run in the summer covered?

retmil46 · **Posted:** Fri Jan 04, 2008 3:23 pm

weantright wrote:

Retmil where is the fuel cooler? Easy to see from underneath? What did you cover it with? Do you run in the summer covered?

I've got it mounted on the transfer case skid plate, behind the transfer case, in the fuel return line to the tank. It's a Setrab oil cooler, 6" L x 3" H x 2" thick. Have to crawl underneath on the drivers side to get to it.

I cut the top flaps off of a cardboard box I had in the back and tystrapped a piece of cardboard on both sides of the cooler. BTW, those cheap colored tystraps from Wally World snap like matchsticks when it's 18 F outside - luckily I had some heavy duty NAPA tystraps left over from installing my grille blockers.

During the summer when it's up in the 80's and 90's, I run with it uncovered.

BTW, the fuel cooler is my own add-on - it's not stock OEM equipment - so if you haven't added one yourself, your CRD won't have one.

weantright · **Posted:** Fri Jan 04, 2008 4:26 pm

Why did you put a fuel cooler on?? Hot fuel is good in a diesel.

BankNote4X4 · **Posted:** Sat Jan 05, 2008 12:34 am

weantright wrote:

Why did you put a fuel cooler on?? Hot fuel is good in a diesel.

It keeps the fuel from getting too hot for the lift pump(also aftermarket). Because the high pressure mechanical pump will bypass fuel it doesn't need it sends hot fuel back into the tank. It was also said to help keep the diesel from foaming.

retmil46 · **Posted:** Sat Jan 05, 2008 11:16 am

Also, if the fuel gets too warm, as detected by the fuel temp sensor in the fuel filter assembly, the ECM will start derating the engine - it uses fuel temp to adjust timing and other parameters. And if fuel temp gets up into the neighborhood of 170 F, it will go into a form of "limp mode" to protect the engine and CP3 injection pump - fuel that's too hot doesn't lubricate very well.

This past summer, when temps were up to 100 F and above, I saw temps pushing up to 140 to 160 F on the fuel filter - that was fuel coming from the tank. Vapor point of diesel can be anywhere from 125 to 140 F depending on what blend it is.

CATCRD · **Posted:** Sat Jan 05, 2008 8:50 pm

Not trying to be contrary, but as another data point, I've been running the ORM all winter and have not had any trouble starting down to 10ºF.

onthehunt · **Posted:** Sun Jan 06, 2008 9:08 pm

Not to be contrary either but... I've never had my diesel fuel too hot (in anything) nor have I seen a diesel out of service for "too hot" of fuel. If it actually derated because of "too hot" of fuel you would get better mpg since less fuel is being burned. I've never seen a bump in fuel mileage because I changed the fuel filter.

Goglio704 · **Posted:** Mon Jan 07, 2008 12:24 am

Correct me if I'm wrong, but aren't there other HPCR diesels with fuel coolers fitted from the factory? I don't have a firm opinion on whether a cooler would benefit our jeeps, but if they are found on other platforms, I think it is fair to say they are not total snake oil.

onthehunt · **Posted:** Mon Jan 07, 2008 12:57 am

You can find them on super duty types and on modded ho diesels. All of which the kj is not. Everyone already has the most effective fuel cooler already installed from the factory- the fuel tank. I fail to see the need of a fuel cooler in the kj and think it would actually hurt the economy, as retmil46 has discovered.

ORM and cold starts

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