Cold start problem help request

dh100m · **Posted:** Sat Nov 14, 2015 10:34 am

I use a amp volt meter inline with main battery for glow plug draw very accurate for on off times and can tell if 1 or more are faulty
in the winter below -10c i have a 2nd battery in the back connected to starter motor direct with welding cable disconnects for
summer use sit in tupper ware container might help you never had trouble starting last winter coldest in north east for years

rankom · **Posted:** Sat Nov 14, 2015 1:14 pm

OK so after my jeep spent a night outside (temp 2c or 35 f) started after 3-4 sec delay same as before , so new ATS (grill location) so replacing it does not improve cold start, i will order boost - air intake sensor , and try that one day ,, if would help? i don't think GDE eco tune or pilot injection is the issue , it could be e-tecno GP . but some guys starting with them NO PROBLEM.

Yeti · **Posted:** Sat Nov 14, 2015 1:43 pm

I think the problem is the glow plug , especially if you have the last revision , I think is the same of the 5v Bosch technology

rankom · **Posted:** Sat Nov 14, 2015 2:38 pm

thanks Yeti , like i said it does not bother me much because i can plug it block heater but like another friend said if i want to go skiing and park it at the ski resort I'm screwed ,

Yeti · **Posted:** Sat Nov 14, 2015 3:00 pm

mmmmm no , you can start the engine , but you need to cycle the key 2-3 time ........ps parking with the nose at south , adding some fuel antigelling and you are ready

dyneq · **Joined:** Tue Feb 19, 2013 1:01 pm **Posts:** 22

OP here. First, I had this problem (no start at >9,000 ft elevation with very low temps <10F) before I flashed the GDE Eco tune, so I doubt that's the issue. It has never left me stranded, but it takes 15-20 mins of start attempts before it will just barely start. I have tried experimenting with double key-ons, but it makes no difference. Once it does start, it produces thick, black smoke and runs poorly until I drive slowly (feathering the accelerator pedal) for a while.

My goal here is to get it to start on the first or second crank. I would expect it to be a bit rough at first at that low of a temperature and I'd be OK with that. I'd rather not install an intake air heater or carry a generator, etc. It seems reasonable to me that it should start in these conditions.

I have some new readings from my OBD2 reader after leaving it parked outside overnight:

Intake Air Temperature 42.8F (actual ambient temperature 29F)
Coolant Temperature 38 (actual coolant temp was the same)

According to the manual (page 1605), air intake temperature is monitored by the MAP sensor. Is it possible that the air temp in the intake manifold was still that warm after sitting overnight, or should I replace it?

The other thing that seems logical to look at is how the CRD monitors barometric pressure (BP) to calculate altitude since it starts fine at home (~5,500 ft). From the 2005 manual at http://colorado4wheel.com/manuals/Jeep/KJ/

Page 294:

Quote:

The ECM also incorporates the barometric pressure sensor in it’s housing

Page 1560 (gas engine)

Quote:

At key-on, the PCM powers up and looks at MAP voltage, and based upon the voltage it sees, it knows the current barometric pressure (relative to altitude).

And, most interestingly, (from that same page):

Quote:

As the altitude increases, the air becomes thinner (less oxygen). If a vehicle is started and driven to a very different altitude than where it was at key-on, the barometric pressure needs to be updated. Any time the PCM sees Wide Open Throttle (WOT), based upon Throttle Position Sensor (TPS) angle and RPM, it will update barometric pressure in the MAP memory cell. With periodic updates, the PCM can make its calculations more effectively.

Questions:
Are there really 2 BP sensors in Libertys (ECM and MAP)? If so, how is the one in the ECM used? I couldn't find any mention of the ECM one other than page 294.

Does the CRD's PCM also use the MAP to determine BP? It doesn't talk about that in the diesel sections of the manual at all, so I'm not sure.

CRDs don't have a throttle valve, so there's no way to measure a WOT. How (if at all) do they calculate altitude?

rankom · **Posted:** Sat Nov 14, 2015 8:46 pm

OK i think ,like i said before , I'm going to try one more sensor replacement (air intake temp - boost sensor)if this does not help faster cold start , ill put in old ceramic gp to see if they can start this thing quickly i have 3 good ceramic GP , i need to get one more just for test.

nursecosmo · **Posted:** Sat Nov 14, 2015 11:35 pm

I too have had trouble with cold starts ever since the 5 volt lug recall fiasco from Jeep. When I got the hot tune from GDE, Keith put the 7 volt logic back into the tune. It worked better than ever for one winter but last winter a couple of the 5 volt plugs burnt out as I knew they would because of the over voltage. Anyway, When I took it to the dealer to reinstall 7 volt plugs, they only put 3 plugs in because they couldn't get the #3 plug out. Of course 3 7V plugs and 1 5V plug do not play well together and I was really tired of arguing with them and so I just left it that way instead of chancing their monkey breaking the plug off in the head.

I got tired of messing with hard starts and GP issues every other winter so I installed this a couple of months ago...
http://www.ebay.com/itm/Ether-Start-Kit ... ag&vxp=mtr

Because of the unusually warm fall we have had here, I have not been able to use it until this morning with temps in the 20s (put warm temps and ether together and bad things happen). Well, it popped right off beautifully. I believe that my cold start issues are cured forever. BTW, I unplugged the glow plugs so that my manifold doesn't blow up. I need to give Keith a call to see how much it would cost for a tune update to eliminate the CEL because of unplugged GPs, but will have wait until I'm rich an famous.

flash7210 · **Posted:** Sun Nov 15, 2015 8:09 am

Quote:

Does the CRD's PCM also use the MAP to determine BP? It doesn't talk about that in the diesel sections of the manual at all, so I'm not sure.

The main purpose of the MAP sensor is to tell the ECM the boosted air pressure from the turbo. What role this plays in extreme cold weather starts I do not know.

Quote:

CRDs don't have a throttle valve, so there's no way to measure a WOT. How (if at all) do they calculate altitude?

The accelerator pedal is the throttle. Mash it to the floor and you will be at WOT.
Use torque pro to check MAP sensor pressure at idle. At your altitude this should be a negative value or vaccuum.
Here at sea level, my idle MAP sensor reading is about +0.2 psi.
And the max MAP pressure I have seen (stock ECM tune) is 22 psi, under hard acceleration.

Its certainly pssible that you have a bad MAP sensor. But before you buy a new one, pull out the one you have and see if it needs a cleaning.

dyneq · **Joined:** Tue Feb 19, 2013 1:01 pm **Posts:** 22

Thanks, I understand the MAP's role once the Jeep is started. I was wondering if, like is described for the gas engines in the service manual, it's also used to determine altitude for the CRD (since that's my main reason for creating this thread). There is nothing about that in the diesel section of the manual, but doesn't it seem logical to want to know what kind of air is coming in so it can adjust the fuel/air ratio optimally?

I've read in other threads that the MAP is a delicate item and can easily be damaged (there's a post on this forum by GDE warning about this) and it's the original, 10 year old sensor. I found one for a reasonable price and will most likely go that route this time. I just replaced my crankshaft position sensor (no start condition) and was thinking about replacing the camshaft position sensor too since it's one of the sensors used for starting. I don't usually throw $ on parts without testing, but it seems like cheap insurance for a vehicle that we use to access remote areas (sometimes extremely remote!).

I will post back with any significant findings. Considering a trip next month where I'd be leaving it at a 10,000ft trailhead overnight (I've had trouble starting it there before).

olypopper · **Posted:** Sun Nov 15, 2015 2:44 pm

Diesel engines are not the same as petrol fired engines. Air fuel ratio swings wildly in a diesel as fuel delivery is what controls rpm. Gasoline engines must maintain correct ratio or they run rich or lean, not diesels.

Yeti · **Posted:** Sun Nov 15, 2015 2:52 pm

the altitude is read by the barometer in the ECU , you can see it outside the ECU is a black plastic round , and when you are in closed loop ..........1st start after .......like 8 hours .......the barometer do not influence the engine managment until the water temp arrive at 21 Celsius or the intake temp arrive at 10 celsius ......or what comes first.........approximately afther that you are in open loop and the barometer influence the quantity of fuel and rail pressure ......etcc

Silverbullet · **Posted:** Sun Nov 15, 2015 10:31 pm

rankom wrote:

OK i think ,like i said before , I'm going to try one more sensor replacement (air intake temp - boost sensor)if this does not help faster cold start , ill put in old ceramic gp to see if they can start this thing quickly i have 3 good ceramic GP , i need to get one more just for test.

I just went to etecnos, i have 3 "good" ceramics with a date stamp of 6-2-2010 if you or anyone wants them let me know, if not I'm smashing them

dgeist · **Posted:** Mon Nov 16, 2015 10:27 am

dyneq wrote:

I've read in other threads that the MAP is a delicate item and can easily be damaged (there's a post on this forum by GDE warning about this) and it's the original, 10 year old sensor. I found one for a reasonable price and will most likely go that route this time. I just replaced my crankshaft position sensor (no start condition) and was thinking about replacing the camshaft position sensor too since it's one of the sensors used for starting. I don't usually throw $ on parts without testing, but it seems like cheap insurance for a vehicle that we use to access remote areas (sometimes extremely remote!).

I had turbo actuation issues recently and replaced the MAP as part of my troubleshooting. Most of the issues were gone. Frankly, it's used by a lot of systems and it's easy to reach and replace, so it doesn't hurt to try. IDParts has good pricing and great shipping on small items like this, BTW (and they support the community). Worst case: you have a perfectly serviceable spare for next time something else takes out the MAP (like oil sludge from the EGR).

Dan

95Z28A4 · **Joined:** Sun Mar 30, 2014 9:53 am **Posts:** 297

I still have the ceramics at 82k miles. I have a set of 7 volt steel Etecnos to install when the timing belt is changed (soon). The CRD is my wife's daily driver. She drives 3k miles/month. I am concerned about harder starting for her with the Etecnos. Last winter, I instructed her to wait until the chime stopped dinging before cranking. When the temp dipped below freezing, I instructed her to cycle the key twice. She doesn't mind because we live in Louisiana and the temp dips below freezing less than 10 times per year. But if the Etecnos make starting more difficult and the CRD is rough running until it warms, she may not like it.

I purchased on of these intake grid heaters from an ebay auction. The seller told me it is from a gen set with 5.9L Cummins. Unlike the grid heater on the Cummins 12 valve in my 1998 Dodge, it only has one heating element. I know it won't work without modifications. I have the weeks elbow kit. I am hoping I can install this grid heater in place of the weeks adapter at the intake manifold with minor modifications. For $30, it's worth a shot.

http://www.ebay.com/itm/252048063454?_t ... EBIDX%3AIT

rankom · **Posted:** Wed Nov 18, 2015 9:44 pm

OK this is what i discovered today,, just going through my toolbox. glow plugs that i purchase from id parts back in dec 2013 are 7v e-tecno GX3123 7 D43 brown colour ring , (skinny tip) this are bad bach , didn't last , set i got in 2014 march is GX3123 7V R94 bigger tip black colour ring , 1st set was maid in e.u. 2nd set in italy , so that is the difference and they almost look a like , i imagine 2nd set is better quality but when i spoke to id parts about it back in 2014 they didn't give me any update , so i learnt the hard way .

Joe Romas · **Posted:** Fri Jan 01, 2016 9:23 am

My cold start seems to be worse this year than previous. Recap.

It's always started but has not been given the chance not to. (never left outside)
06 bought new, now has 67k miles, problem recognized the second winter I owned it.
GDE tune since the second summer I owned it.
Takes several revolutions to start beginning previously in low 40f's but is getting closer to 50f.
06 original GP's.
Same with original and GDE updated ECM eliminating internal baro sensor.
Has temp sensor on passenger lower inside radiator mount and NO evic.
I have the GDE "Full Torque" tune and I think it "pounds" more than I think it should all the time.
It's a "Garage Queen" in a garage that's heated to 40f and rarely outside.
I have a VAG-COM that recognizes the ECM but I've not seriously checked readings so far.

Reading through this thread it appears the MAP is the good suspect but no one has indicated finding a cure on this thread.

So I ordered a MAP from ID parts, $25 plus $5 S&H, and will try that first.

Silverbullet · **Posted:** Fri Jan 01, 2016 12:01 pm

Would love to know what your MAP looks like when you pull it, if you haven't already

rankom · **Posted:** Fri Jan 01, 2016 6:35 pm

Joe i did replace MAP and ambient sensors , didn't help cold start , I'm using block heater , make sure the battery is good , if i leave it outside just to test it in the cold mornings , it starts and dies few times i have to cycle key again , my engine compression is good i done tons of work to it, i seen some crd (cold start videos) start right up , with 7v etecnos GP mine won't start without fight , I'm just going to call it good as it is.

dntlkbak · **Posted:** Fri Jan 01, 2016 7:45 pm

Mine basically wont start in cool weather after installing Etechno's, It's fine when the block heater is plugged in but in cold weather forget it, The old ceramic GP's worked fine, I dont believe the 7V metal Etechno's do anything?

Cold start problem help request

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