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+--- Thread: slow cold starting issues (/showthread.php?tid=8418)
slow cold starting issues - 50harleyrider - 10-20-2020
Cold starts are slow. Starter cranks engine fast but I have to keep it cranking for 2-3 seconds after it starts firing to get it running on its' own. Only happens when engine is totally cold. Warm starts are great. I know the 606 needs pre start glow so would this be a glow plug issue? They all show continuity when I check them at the 6 pin connector. Any ideas what to look for?
RE: slow cold starting issues - baldur - 10-20-2020
If the glow plugs weren't working it would not be slow starting, it simply would never start. The OM606 won't start without glow plugs unless it's fully warmed up to 80+ degrees C.
I would say more likely you have a small leak introducing air into the injection pump. Does it run OK once it starts cold or does it buckle and puff smoke for the first 20 seconds?
RE: slow cold starting issues - TE27Levin - 10-22-2020
I am having the same issue. I am looking to plug this thing in this evening in fact. - 13c in the rocky mountains already!
RE: slow cold starting issues - vica153 - 10-22-2020
Might just come down to slightly lower compression as the engine gets higher miles. My 606 with all new glow plugs starts ok, 1-2 revolutions. My friends freshly rebuilt 617 starts up in less than a revolution, every time, even cold.
If all your prechambers and glow plugs are good, then compression is pretty much the only thing left. Maybe a worn out lift pump not getting enough pressure quickly enough, but even with my electric lift pump it doesn't start the best.
RE: slow cold starting issues - TE27Levin - 10-22-2020
(10-22-2020, 02:15 PM)vica153 Might just come down to slightly lower compression as the engine gets higher miles. My 606 with all new glow plugs starts ok, 1-2 revolutions. My friends freshly rebuilt 617 starts up in less than a revolution, every time, even cold.
If all your prechambers and glow plugs are good, then compression is pretty much the only thing left. Maybe a worn out lift pump not getting enough pressure quickly enough, but even with my electric lift pump it doesn't start the best.
The car my engine came out of supposedly had 174 000 kms on the cluster. I never checked my compression... It did have a bad injector or two.. But then I had new nozzles installed on all and calibrated at a diesel shop up here. New dieselmeken pump too.
I checked the glow plugs individually in a vice with a booster pack and reamed the holes and shoved them back in. They were NGKs.. I imagine I can make it start better with the glow plug settings on the dsl1. It has been very cool to work with.. I have my stock in tank gas pump with a regulator to bring it down to 15 psi so i do not believe I have a fuel supply issue.. Still has lots of power. Just wont start worth a damn when cold. I am leaning on possibly compression...
RE: slow cold starting issues - X Double Dot - 10-23-2020
I would expect there to be some white smoke when it does start IF some or all of the glow plugs weren't firing. Since I know you have the dsl1, take a look at your fuel request and pump position while cranking, it should stroke up a good deal while cranking.
I experimented with reducing how much it would stroke up while cranking to avoid how high it would rev when it did fire on mine once. If I reduced it too much it wouldn't "catch" like you are describing and would take a few more revolutions of me holding the starter for it to stay running.
Maybe unrelated, but i'll share anyways, IP wise, I replaced my delivery valves due to some not sealing well. If they don't seal well they let the pressure in the lines bleed off in between firing events (or letting the car sit) and then the next time it takes a few extra strokes of the pump to build the pressure for the IP to fire. If they are really bad like mine they'll leak between firing events and cause retarded timing. I tried new crush washers twice with no luck until I tried "new" delivery valve elements from a used pump. Immediately the nailing at cold starts went away, the white smoke puff at start up went away, the car started with less cranks, and i even had to reduce the "fuel request approximation" at idle because the lines weren't bleeding as much fuel off anymore. there's a thread on peach parts that made me look in to this. some people has been able to polish the sealing face on the check valve with success too.
RE: slow cold starting issues - TE27Levin - 10-24-2020
I have also noted with my Glow plug indicator on the dash. That when the engine is up to operating temperature, if it is having a hard time idling from the alternator loading up, the glow plugs will engage and further load the alternator and cause an idle oscillation that will go out of control and make it smoke like crazy until you stab the gas pedal. I have bumped up my idle to 800 rpm to make it less noticeable.
Still some bugs I gotta work out... Have any of you also noticed this? I am running a Gm 145 amp alternator that is controlled by a GM PCM with no crank trigger though, so it is running a base (key on engine off) pwm signal to the alternator regulator.. That is most likely contributing..
Does the DSL1 use a strategy to engage the glow plug relay if the idle goes below a certain threshold to try and help it get up to idle, even though its at an after glow time of zero?
RE: slow cold starting issues - 50harleyrider - 10-25-2020
mine fires right up when warm. When cold it does seem to stumble and blow some black smoke when it does start and I have to get the revs up to clear it out and then it's fine. I've increased the pre-start glow time with no success. It's like it gets too much fuel on fully cold starts. There's probably a way to address that in DSL1. Hopefully Baldur will see this post and pipe in again. The air temperature fuel limit modifier may play in but I doubt it because mine still starts right up after the initial cold start even when the air temp is low. The DSL1 fuel limit table is controlled by boost and it goes down to 800 and 1000mb values. My starting boost is at 1082 mb so I might adjust the max fuel values down to lean the starting fuel amount. 14.7 = 1013 mb so I am showing a little boost above atmospheric.
RE: slow cold starting issues - TE27Levin - 10-25-2020
Mine fires right up when warm as well.
But know what else I found effects starting at cold temperatures? When you fasten your starter motor in between your bendstens speed gems adapter plate, and the mercedes engine and neglect to loctite them on. I discovered my starter was loose when I went to boost right to its terminal this morning. Since the block heater wasn't helping much. Now I am in the process of removing my 4l65e to tighten my starter... RAGE.
EDIT: Update: Turns out the top bolt for the starter which is about 4 inches long, fell out, and got fired out of the little sheet metal inspection hole on the 4l65 bellhousing miraculously causing no damage. If that isn't a miracle I do not know what is.
RE: slow cold starting issues - 50harleyrider - 10-26-2020
Can anyone running DSL1 check their dashboard and see what their rack command and rack positions are at initial key on? My position is 322 and my rack command is at 264. This doesn't look right to me.
RE: slow cold starting issues - baldur - 10-26-2020
The most useful information in analysing a cold start is to look at what the cranking RPM is and what rack position it goes to when cranking. Also, whether pushing the pedal to the floor aids in starting.
RE: slow cold starting issues - 50harleyrider - 10-27-2020
baldur The most useful information in analysing a cold start is to look at what the cranking RPM is and what rack position it goes to when cranking. Also, whether pushing the pedal to the floor aids in starting.Thanks Baldur.I was able to get the cranking fueling decreased a little and it starts right up cold now. Now that I am actually far enough along, I am attempting some tuning to get my fuel mileage up and had a question about decreasing the smoke map on initial takeoff. is it best to do this in the fuel request table or the fuel limit table or both? the smoking starts at about 1000 RPM where the boost is starting to build. It stops at 1400 RPM where boost ramps up a lot. It does it from 30% throttle and upward. Black smoke only so I assume fueling. It's not "rolling coal" but still probably too much.
RE: slow cold starting issues - baldur - 10-27-2020
It's best done in the limit table.
RE: slow cold starting issues - TE27Levin - 10-31-2020
(10-26-2020, 07:18 AM)50harleyrider Can anyone running DSL1 check their dashboard and see what their rack command and rack positions are at initial key on? My position is 322 and my rack command is at 264. This doesn't look right to me.
At -2 c the rack position went to 2000 ?? this morning.. I let the plugs glow six times. Misfired, stumbled, revved up and hunted a bit.. Grey smoke. But ready to roll without too much of a fuss.
RE: slow cold starting issues - X Double Dot - 11-02-2020
(10-31-2020, 05:32 PM)TE27Levin(10-26-2020, 07:18 AM)50harleyrider Can anyone running DSL1 check their dashboard and see what their rack command and rack positions are at initial key on? My position is 322 and my rack command is at 264. This doesn't look right to me.
At -2 c the rack position went to 2000 ?? this morning.. I let the plugs glow six times. Misfired, stumbled, revved up and hunted a bit.. Grey smoke. But ready to roll without too much of a fuss.
TE27Levin, I assume the 2000 was when you were cranking the engine? and 50harleyrider I assume that was no cranking, no pedal input?
I think the 264 vs 322 missmatch could be due to 332 being the lowest the rack can get to, or since the engine wasn't running, and assuming the oil was cold maybe it just didn't have enough umph to shift that small distance? If it's always the case though that it can't get to 264, then I think you'd want to reset your min rack command to match 322.
RE: slow cold starting issues - 50harleyrider - 11-03-2020
Can someone check their cold cranking RPM? I have a new battery but am thinking it and a healthy starter should spin the engine higher than 600 rpm. Baldur suggested possible air in the system. Got to figure out how to verify that. Metal contraction/expansion in the IP components may be allowing air in only when cold.
Something is wrong when you have to cycle the glow plugs 6 times, TE27Levin.
RE: slow cold starting issues - TE27Levin - 11-03-2020
(11-03-2020, 02:09 PM)50harleyrider Can someone check their cold cranking RPM? I have a new battery but am thinking it and a healthy starter should spin the engine higher than 600 rpm. Baldur suggested possible air in the system. Got to figure out how to verify that. Metal contraction/expansion in the IP components may be allowing air in only when cold.
Something is wrong when you have to cycle the glow plugs 6 times, TE27Levin.
You think? Its only when it is dead cold, like below freezing. I have a glow plug indicator led tapped off glow plug #1. So I just watch the light go on and off six times. It works different than how the factory Mercedes cluster shows the glow plug time.
I am running dual batteries. With my auxiliary battery running directly to my glow plug fuse. And I also ran an extra 2 gauge wire to my starter along side the factory GM starter cable. But Going directly from my top post. This seemed to help with engine cranking. Ill hook up the computer and monitor cranking rpm after work today. Although it is pretty warm this week.
X Double Dot.
yes the 2000 value was during cranking.
RE: slow cold starting issues - 50harleyrider - 11-04-2020
this morning at 2degrees c, my cranking speed was 350 RPM. Voltage was 13v so I don't think my battery is the problem. still would not start . I floored it and it finally started slugishly
RE: slow cold starting issues - AlanMcR - 11-04-2020
One of the four internal brushes on my starter stick. That effectively cut the starter power in half. Resulting in slow cranking and higher than expected voltage during cranking.
RE: slow cold starting issues - 50harleyrider - 11-04-2020
can anyone report cranking rpm?
RE: slow cold starting issues - AlanMcR - 11-04-2020
How are you measuring?
RE: slow cold starting issues - 50harleyrider - 11-04-2020
on the dashboard of Baldurs' BG Calibrator. With the key on, a digital or analog tach should work. I'm gonna look into two batteries.
RE: slow cold starting issues - TE27Levin - 11-04-2020
(11-04-2020, 11:34 AM)50harleyrider can anyone report cranking rpm?
With the baldur software I saw 150 rpm before it dialed to life.
RE: slow cold starting issues - X Double Dot - 11-05-2020
I remember mine cranking around 300rpm when I last looked. The I value for idle would start to ramp up the fuel considerably if it cranked for awhile which I believe led to a the high rev once the engine caught. I ended up reducing my I-value limit down some to try to reduce that.
RE: slow cold starting issues - 50harleyrider - 11-06-2020
I installed the original battery out of the donor w210 in my truck today. I had to relocate the washer reservoir as it is a group 49H8 battery but it has 900 cca at 0F and 150 amps reserve so worth trying. My F-150 cables stretched barely to fit but did. Mercedes chose it for a reason back in 1999. For the record, the fully charged state was 12.8v. It fired right up spinning the engine at 400 rpm leaving it engaged up to 700RPM starting. A little tweaking of simple rack position request and it should be fine now. Thanks for all the input and to cap the thread, I advise a big strong battery with at least 12.3 volts. Of course 2 batteries with one dedicated to starting would be ideal but room and wiring would always be a pain and MB didn't do it and there aren't too many places in NA colder than Germany lol.
RE: slow cold starting issues - TE27Levin - 11-09-2020
Any one have any clues on why the glow plugs will keep cycling after 5 minutes of run time and beyond? Specifically It seems whenever the RPMS approach idle, my glow plug relay will fire up. It loads the hell out of my alternator ( I watch the voltmeter sky dive) and makes the idle oscillate and smoke. Mr. Baldur any theory's?
RE: slow cold starting issues - baldur - 11-10-2020
(11-09-2020, 01:41 PM)TE27Levin Any one have any clues on why the glow plugs will keep cycling after 5 minutes of run time and beyond? Specifically It seems whenever the RPMS approach idle, my glow plug relay will fire up. It loads the hell out of my alternator ( I watch the voltmeter sky dive) and makes the idle oscillate and smoke. Mr. Baldur any theory's?
Are you running old firmware?
RE: slow cold starting issues - X Double Dot - 11-10-2020
(11-09-2020, 01:41 PM)TE27Levin Any one have any clues on why the glow plugs will keep cycling after 5 minutes of run time and beyond? Specifically It seems whenever the RPMS approach idle, my glow plug relay will fire up. It loads the hell out of my alternator ( I watch the voltmeter sky dive) and makes the idle oscillate and smoke. Mr. Baldur any theory's?
I have/had the same issue with my idle going crazy whenever the GP relay fired. I believe there is a correctly tuned rack PID and voltage correction table to make this go away...however I never could get one to work.
Mine was so bad that in first gear when the GPs kicked off the entire truck would buck as the rack position would considerable jump due to the voltage change.
I went to far as to add a second battery, about half size, that solely runs the GPs to avoid this. It uses a charger with a diode to keep it isolated from the main system. it works to reduce the idle oscillation and i'm just working through some issues keeping the battery charged.
If a solution is found to keeping the rack position stable with 2v spikes in the system let me know!
RE: slow cold starting issues - baldur - 11-10-2020
One thing that is important to keep the voltage compensation working right is that the low pass filter setting on the supply voltage must not be too high. I would recommend no more than 99.50%, but a little lower is better.
RE: slow cold starting issues - TE27Levin - 11-10-2020
(11-10-2020, 06:45 AM)baldur(11-09-2020, 01:41 PM)TE27Levin Any one have any clues on why the glow plugs will keep cycling after 5 minutes of run time and beyond? Specifically It seems whenever the RPMS approach idle, my glow plug relay will fire up. It loads the hell out of my alternator ( I watch the voltmeter sky dive) and makes the idle oscillate and smoke. Mr. Baldur any theory's?
Are you running old firmware?
I am running v 1.25 on serial 00268
RE: slow cold starting issues - TE27Levin - 11-10-2020
(11-10-2020, 09:14 AM)X Double Dot(11-09-2020, 01:41 PM)TE27Levin Any one have any clues on why the glow plugs will keep cycling after 5 minutes of run time and beyond? Specifically It seems whenever the RPMS approach idle, my glow plug relay will fire up. It loads the hell out of my alternator ( I watch the voltmeter sky dive) and makes the idle oscillate and smoke. Mr. Baldur any theory's?
I have/had the same issue with my idle going crazy whenever the GP relay fired. I believe there is a correctly tuned rack PID and voltage correction table to make this go away...however I never could get one to work.
Mine was so bad that in first gear when the GPs kicked off the entire truck would buck as the rack position would considerable jump due to the voltage change.
I went to far as to add a second battery, about half size, that solely runs the GPs to avoid this. It uses a charger with a diode to keep it isolated from the main system. it works to reduce the idle oscillation and i'm just working through some issues keeping the battery charged.
If a solution is found to keeping the rack position stable with 2v spikes in the system let me know!
My truck was seriously lurching and surging in drive with my foot on the brake the other day. I have the dual battery set up. As long as my volt meter is above 14v the issue does not occur. So that means with no electrical load, no defrost and no heater fan or wipers. Ill look into those voltage settings.
RE: slow cold starting issues - baldur - 11-10-2020
(11-10-2020, 07:19 PM)TE27Levin(11-10-2020, 06:45 AM)baldur(11-09-2020, 01:41 PM)TE27Levin Any one have any clues on why the glow plugs will keep cycling after 5 minutes of run time and beyond? Specifically It seems whenever the RPMS approach idle, my glow plug relay will fire up. It loads the hell out of my alternator ( I watch the voltmeter sky dive) and makes the idle oscillate and smoke. Mr. Baldur any theory's?
Are you running old firmware?
I am running v 1.25 on serial 00268
The glow plug control strategy has changed since then.
RE: slow cold starting issues - 50harleyrider - 11-11-2020
One thing I haven't had issue with on any of Baldurs' firmwares is glow plugs affecting idle. I do always upgrade to the latest firmware on his website regardless. check your PM.
RE: slow cold starting issues - X Double Dot - 11-12-2020
regardless of the firmware, any time the relay closes while the truck is running its going to cause the voltage to drop momentarily as an 80amp load is immediately applied...and (unless tuned properly) the rack position will likely move too as the PID loop tries to compensate. Unless you have a relay that slowly opens and closes I believe this is going to happen. I'm using a standard (maybe a starter relay) that is just off/on. My understanding is that the mercedes one as controlled by the DSL1 works the same, however it's probably key to note if we're using different relays.
I've had the issue on all firmwares up to v34. (Note my low pass filter voltage was 99.92% instead of the <99.5% recommendation)
Baldur, 1) thanks for making CNTL+F work for finding variables. 2) why isn't the default for the low pass voltage filter set to 99.5 or below as recommended? Noticed mine was/probably has always been the 99.92 default.
RE: slow cold starting issues - 50harleyrider - 11-12-2020
where is the low pass voltage filter in the software?
TE27Levin, have you calibrated your rack? Mine did a similar lurching in the beginning until I did per Baldurs' direction. You shouldn't need a battery dedicated to glow plugs. Maybe Baldur has an opinion on that.
RE: slow cold starting issues - X Double Dot - 11-12-2020
(11-12-2020, 09:52 AM)50harleyrider where is the low pass voltage filter in the software?the fastest way to find it is to hit "CNTL+F" on the main Screen in the calibrator, then type in "low pass voltage" and it will show up.
TE27Levin, have you calibrated your rack? Mine did a similar lurching in the beginning until I did per Baldurs' direction. You shouldn't need a battery dedicated to glow plugs. Maybe Baldur has an opinion on that.
RE: slow cold starting issues - 50harleyrider - 11-12-2020
X Double DotMine is also set to 99.92. Per Baldurs' post, I'm lowering it to 99.5.50harleyrider where is the low pass voltage filter in the software?the fastest way to find it is to hit "CNTL+F" on the main Screen in the calibrator, then type in "low pass voltage" and it will show up.
TE27Levin, have you calibrated your rack? Mine did a similar lurching in the beginning until I did per Baldurs' direction. You shouldn't need a battery dedicated to glow plugs. Maybe Baldur has an opinion on that.
RE: slow cold starting issues - TE27Levin - 11-12-2020
(11-12-2020, 10:14 AM)X Double Dot(11-12-2020, 09:52 AM)50harleyrider where is the low pass voltage filter in the software?the fastest way to find it is to hit "CNTL+F" on the main Screen in the calibrator, then type in "low pass voltage" and it will show up.
TE27Levin, have you calibrated your rack? Mine did a similar lurching in the beginning until I did per Baldurs' direction. You shouldn't need a battery dedicated to glow plugs. Maybe Baldur has an opinion on that.
Alright, so I have a few things to take care of!. Ill update my firmware first.
EDIT. I updated the firmware. The glow plugs seem to be kicking off even worse now. Even at 0.0 at x temperature they are still lighting off making my alternator load up and the idle hunt. Not sure what is going on.
RE: slow cold starting issues - baldur - 11-13-2020
(11-12-2020, 06:08 PM)TE27Levin(11-12-2020, 10:14 AM)X Double Dot(11-12-2020, 09:52 AM)50harleyrider where is the low pass voltage filter in the software?the fastest way to find it is to hit "CNTL+F" on the main Screen in the calibrator, then type in "low pass voltage" and it will show up.
TE27Levin, have you calibrated your rack? Mine did a similar lurching in the beginning until I did per Baldurs' direction. You shouldn't need a battery dedicated to glow plugs. Maybe Baldur has an opinion on that.
Alright, so I have a few things to take care of!. Ill update my firmware first.
EDIT. I updated the firmware. The glow plugs seem to be kicking off even worse now. Even at 0.0 at x temperature they are still lighting off making my alternator load up and the idle hunt. Not sure what is going on.
E-mail me your config file.
RE: slow cold starting issues - TE27Levin - 11-16-2020
(11-13-2020, 11:27 AM)baldur(11-12-2020, 06:08 PM)TE27Levin(11-12-2020, 10:14 AM)X Double Dot the fastest way to find it is to hit "CNTL+F" on the main Screen in the calibrator, then type in "low pass voltage" and it will show up.
Alright, so I have a few things to take care of!. Ill update my firmware first.
EDIT. I updated the firmware. The glow plugs seem to be kicking off even worse now. Even at 0.0 at x temperature they are still lighting off making my alternator load up and the idle hunt. Not sure what is going on.
E-mail me your config file.
Sent.
RE: slow cold starting issues - 50harleyrider - 11-27-2020
Mine is doing the slow 'sitting a day or two' start and it'd driving me crazy. I want to look for air in the pump. Baldur and xdoubledot both mention this in their posts. Should I be able to see air bubbles in one or both of the clear lines while cranking if air is intruding?
RE: slow cold starting issues - X Double Dot - 11-27-2020
(11-27-2020, 08:21 PM)50harleyrider Mine is doing the slow 'sitting a day or two' start and it'd driving me crazy. I want to look for air in the pump. Baldur and xdoubledot both mention this in their posts. Should I be able to see air bubbles in one or both of the clear lines while cranking if air is intruding?I think you'd look for the bubble prestart, after it has sat for awhile. Typically look at the lines right as they enter the filter housing, that's typically where they'll form/sit.
RE: slow cold starting issues - 50harleyrider - 11-28-2020
This morning at 9C coolant temperature, I changed my simple rack position request up to 340 at 0, and truck started in just a few seconds. That must be an important value for starting. I had my battery at about 13.2 volts but notice after a 5 second glow, DSL1 was still showing only 11.8 volts. The glow plugs really pull the battery voltage down. I don't like that so I'm considering a second battery for glow plug only also. Any hints for wiring it in to only fire glow plugs? I'm also considering changing the rack position supply voltage so the breakpoint is not at 12v but 11.5v.
RE: slow cold starting issues - X Double Dot - 11-28-2020
(11-28-2020, 08:33 AM)50harleyrider This morning at 9C coolant temperature, I changed my simple rack position request up to 340 at 0, and truck started in just a few seconds. That must be an important value for starting. I had my battery at about 13.2 volts but notice after a 5 second glow, DSL1 was still showing only 11.8 volts. The glow plugs really pull the battery voltage down. I don't like that so I'm considering a second battery for glow plug only also. Any hints for wiring it in to only fire glow plugs? I'm also considering changing the rack position supply voltage so the breakpoint is not at 12v but 11.5v.what is your rack position during cranking? if the rack position (not being high enough) was the issue you should get the same result by pressing the accelerator pedal during cranking.
my battery voltage would drop just as much, if not further, it is an ~80amp load when the GP's kick on.
Right now my second battery is just hooked directly to the GP relay (same chassis ground as the other battery). I have a diode and a ~3amp charger inline on the positive side to charge my GP battery from the main battery thats connected to the alternator. the 3amp charger isn't working well (or at all) so i'm likely going to replace it with a battery isolater than I either flip with a switch or a time delay relay triggered by the glow plugs
RE: slow cold starting issues - 50harleyrider - 11-28-2020
makes sense giving it throttle to see if it starts. That doesn't affect mine at all. I really think I have a cranking voltage drain caused by glow plug draw except this morning per my last post when the DSL1 supply stayed above 11.5 cranking volts on a fully charged battery and pre start glow set at 4 seconds. I want DSL1 to see 12 volts or more all the time. I noticed when it's cranking on a decent battery charge of 12.1, the DSL1 will drop below 11 volts and turn red on the dashboard. Obviously, Baldur didn't want that so he programmed a warning at 11 volts.
I suppose one or more of my glow plugs is drawing too much current. I have to investigate that too. No fuse melts yet.
RE: slow cold starting issues - 50harleyrider - 11-30-2020
I am going to rewire my DSL1 at the back connectors. does anyone know or can check if the 24 pin and 8 pin connectors are standard ATX connections like the motherboard and power supply ones on PC's? I just got rid of an older PC so have nothing to check by. I am probably the worst molex crimper on the planet so I want to get those connectors with pigtails and make my splices on them. baldur informed me that he does use the standard ATX connections so I ordered a connector with wire already attached so I can make easy splices.