ORM and cold starts

weantright · **Posted:** Wed Jan 02, 2008 11:20 am

I have done the ORM (disconnecting the sensor) and have notice hard starting. 45* or lower starting becomes difficult and at 20* or less 4-5 cycles are needed to start. Anyone else notice this? Undo the ORM and cold starts are a lot better and starts on the first cycle.

gmctd · **Posted:** Wed Jan 02, 2008 12:17 pm

Sounds like you're pulling the AAT sensor rather than the MAF sensor..............

nix · **Posted:** Wed Jan 02, 2008 12:58 pm

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?

UFO · **Posted:** Wed Jan 02, 2008 1:12 pm

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?

No, I don't think so. Ours catches immediately and smooths out in 2 or 3 seconds, even in the teens F. And the MAF is disconnected. Maybe you have a glow plug problem....

nix · **Posted:** Wed Jan 02, 2008 1:57 pm

Very strange.. My friend's powerstroke takes longer to start in cold weather.. of course, it sounds like its starter is faster than the one on the CRD. Once my CRD is up to operating temps it starts up on the first try. I always wait for the glowplug light to go out before cranking it over. I haven't thrown any codes yet.

DnA Diesel · **Posted:** Wed Jan 02, 2008 2:17 pm

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.

weantright · **Posted:** Wed Jan 02, 2008 2:46 pm

gmctd wrote:

Sounds like you're pulling the AAT sensor rather than the MAF sensor..............

UFO 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?

No, I don't think so. Ours catches immediately and smooths out in 2 or 3 seconds, even in the teens F. And the MAF is disconnected. Maybe you have a glow plug problem....

No problem when it is warm or a warm motor. It is only when the air box sensor (MAF) is unplugged that the problem rises. No codes thrown so this is why I feel there's a link. When MAF is plugged in it will take 2-3 sec after light goes out, single cycle. Rough running for about 3-5 sec then smoothes out. Glow plug were changed last year and they also triggered a CEL when bad. I have other Diesels so I understand the cold weather starts. Just looking for others that have this issue.

dgeist · **Posted:** Wed Jan 02, 2008 3:18 pm

weantright wrote:

No problem when it is warm or a warm motor. It is only when the air box sensor (MAF) is unplugged that the problem rises. No codes thrown so this is why I feel there's a link. When MAF is plugged in it will take 2-3 sec after light goes out, single cycle. Rough running for about 3-5 sec then smoothes out. Glow plug were changed last year and they also triggered a CEL when bad. I have other Diesels so I understand the cold weather starts. Just looking for others that have this issue.

Is the evidence anecdotal or have you tested it both ways under nearly the same conditions (leave overnight at close to the same temps, etc)? Unless the ECM is doing something to artificially delay startup or using the EGR to smooth things after crank, the disconnect MAF just doesn't lend itself to any kind of causlity... Anyone want to comment on the Bosch controller and/or program?

litton · **Posted:** Wed Jan 02, 2008 4:41 pm

weantright wrote:

gmctd wrote:

Sounds like you're pulling the AAT sensor rather than the MAF sensor..............

UFO 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?

No, I don't think so. Ours catches immediately and smooths out in 2 or 3 seconds, even in the teens F. And the MAF is disconnected. Maybe you have a glow plug problem....

No problem when it is warm or a warm motor. It is only when the air box sensor (MAF) is unplugged that the problem rises. No codes thrown so this is why I feel there's a link. When MAF is plugged in it will take 2-3 sec after light goes out, single cycle. Rough running for about 3-5 sec then smoothes out. Glow plug were changed last year and they also triggered a CEL when bad. I have other Diesels so I understand the cold weather starts. Just looking for others that have this issue.

When I was in MT, the temp got into the single digits and it started about the same as when the temp is in the 50's. Just took a few seconds for all cyliniders to wake up and sing the same song. Sounded like a real diesel for a little bit. Of course the one time I forgot to wait till the glow plug light went out it took a bit longer. FYI, my wife still doesn't ever ever wait til the light goes out.

weantright · **Posted:** Wed Jan 02, 2008 5:03 pm

dgeist wrote:

weantright wrote:

No problem when it is warm or a warm motor. It is only when the air box sensor (MAF) is unplugged that the problem rises. No codes thrown so this is why I feel there's a link. When MAF is plugged in it will take 2-3 sec after light goes out, single cycle. Rough running for about 3-5 sec then smoothes out. Glow plug were changed last year and they also triggered a CEL when bad. I have other Diesels so I understand the cold weather starts. Just looking for others that have this issue.

Is the evidence anecdotal or have you tested it both ways under nearly the same conditions (leave overnight at close to the same temps, etc)? Unless the ECM is doing something to artificially delay startup or using the EGR to smooth things after crank, the disconnect MAF just doesn't lend itself to any kind of causlity... Anyone want to comment on the Bosch controller and/or program?

Yep I sure did. Overnight, cold 20* and I was not the tester. She didn't know what I was doing so the test was as true as I could make it. She reported after 2-3 start-ups when she saw the CEL (ORM) it was hard starting. Then I switched back and she mention after the light was off if became easier to start. I thought it was hard starting when the ORM was done and she backed my feelings. It is noticeable harder to start so it is not in our heads. This was done several times over the past month, temps between 45-15* and tonight it will be 0*.

I didn't think the ORM would change the starting but my test shows different.

UFO · **Posted:** Wed Jan 02, 2008 5:11 pm

Last week I had a interesting starting experience. It was single digits over night, and the CRD was not plugged in. I also had biodiesel in the tank (B20). On starting, it rattled badly and idled very rough. Off idle it ran nice and smooth. Idle was horribly noisy until the engine warmed up, and then it has been totally fine. But on these cold nights now the CRD is getting plugged in.

BlackLibertyCRD · **Posted:** Wed Jan 02, 2008 5:52 pm

Mine was only hard to start when I take to work on a very cold day and gets just half way warm before clocking in for the day. At the end of the work day it would crank a few seconds more with a puff of white smoke from the exhaust then start. Thats properly because there still raw fuel left in the cylinder when I shut it off. It takes longer for the engine to warm up with the ORM because the exhaust is not flowing through the egr and heat exchanger connected to the cooling system. Also the intake temperature stays lower because of no exhaust gases not flowing into it. It's a trade off with the ORM and I can understand why some don't like it. The ORM is not good for short trips in the winter.

railguy · **Posted:** Wed Jan 02, 2008 6:07 pm

I have had the MAF unplugged for several months now. The other day I went out and started the CRD after it had been sitting out in 0 to 20 degree temps for about 3 weeks without being started. One glow cycle, turned over about three times and started right up. I think the OP has an issue other than the MAF being unplugged.

gmctd · **Posted:** Wed Jan 02, 2008 6:20 pm

Barring the cold numb fingers snagging the wrong plug in the wintery dark scenario, you might give the fuel manager head a close inspection, see if the heater plug is melted and leaking Diesel fuel - might also give the primer button a few good pumps to see how long B4 it gets difficult to push as pressure and fuel volume increases

brew1 · **Posted:** Wed Jan 02, 2008 8:56 pm

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.

yakers · **Posted:** Wed Jan 02, 2008 9:10 pm

UFO wrote:

Last week I had a interesting starting experience. It was single digits over night, and the CRD was not plugged in. I also had biodiesel in the tank (B20). On starting, it rattled badly and idled very rough. Off idle it ran nice and smooth. Idle was horribly noisy until the engine warmed up, and then it has been totally fine. But on these cold nights now the CRD is getting plugged in.

Sounds like my experience. I am usually in warm Southern California but was visiting Flagstaff & Grand Canyon a couple weeks back and it was about 10 degrees. Usually I don't even see the glow plug light, this time I did, waited till it went off and the CRD rumbled into life but it turned over several times rattled and ran rough until it warmed up. I have the ORM and 5W40 Mobil TTD. Other cold days (but probably 20+ degrees) it was just normal. Still a better experience than long ago starting my 1966 MB 200D.

litton · **Posted:** Wed Jan 02, 2008 9:39 pm

Is it possible that the original problem is with the glow plugs themselves. I have no idea what turns the little light off, but if a plug or two wasn't working, then it should take a bit more to get it started. One other thought that pethaps the fuel isn't quite winterized.

nix · **Posted:** Thu Jan 03, 2008 12:18 pm

This morning I woke up and it was in the 20's F. I tried turning the key to the "on" position twice.. both times waiting several seconds after the glowplug light went out.. then tried starting the beast. It fired right up immediately. Does that still sound like a glow plug problem to you guys?

weantright · **Posted:** Thu Jan 03, 2008 2:36 pm

railguy wrote:

I have had the MAF unplugged for several months now. The other day I went out and started the CRD after it had been sitting out in 0 to 20 degree temps for about 3 weeks without being started. One glow cycle, turned over about three times and started right up. I think the OP has an issue other than the MAF being unplugged.

gmctd wrote:

Barring the cold numb fingers snagging the wrong plug in the wintery dark scenario, you might give the fuel manager head a close inspection, see if the heater plug is melted and leaking Diesel fuel - might also give the primer button a few good pumps to see how long B4 it gets difficult to push as pressure and fuel volume increases

Can glow plugs work intermediately?? This morning it was 10* and the CRD fired up in one shot (ORM off). ORM on now and tonight it will be 15*. Anyone want bet it will take 3-4 cycles to fire???! No other changes and it will be warmer to boot.

BlackLibertyCRD · **Posted:** Thu Jan 03, 2008 2:52 pm

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.

ORM and cold starts

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