2002 Hard start, occasional stall, not fuel related (this time)

[DanKnoch]

Hello, I am new to this forum.  I spoke to Mopar1973Man on the telephone, Thanks to him for sharing his wealth of knowledge.

 

 

 

Here is the info I provided to the service facility: 

 

"Vehicle information:

2002 Dodge Ram 2500, 5.9 Cummins HO, 6 speed manual, 4x4.

 

Modifications:

Injectors-Formula 1 Mach 2 105hp, Smarty S-03 programmer, FASS.

 

Symptoms:

                For the past 2 months, truck has had issues starting ranging from a hard start to stalling nearly a minute after being started.  This all seems to take place when the temperature is below the operating temperature of 190.  If I make several stops before the truck is at running temp, it usually has trouble every start.  It has not failed to start, just takes longer, and when it has stalled, it has restarted on the first revolution.  When it is trying to start but is having problems, if I back the key from the start position and try again, it starts instantly.  Often, to put it simply, engine will crank-crank-try to start-crank x3 and start and run great. 

 

What I have tried:

                Found a bad relay for the grid heater, replaced the grid heater relay (only code this whole time).  Replaced the Cam position sensor below the VP44.  Took the truck to a local shop who stated they “think” it is the computer but they could not find anything wrong and they didn’t sound convincing enough for me to drop $1000 on an ECM because they “think” that is it.  Tried starting the truck with the lift pump relay pulled so there was no initial fuel pressure-no change.  Per a conversation with Doug of Blue Chips Diesel, I put a heat gun to the VP44 for about 10 minutes one morning and it started and idled good with no symptoms.  Not enough to convince me since sometimes it will start and run without incident. However at that temp, I went about 10 mornings in a row with starting problems, only started good with the heating.  Initially, the symptoms seemed worse with the Smarty programming, after trying different things and stock software, problem was still present. 

 

At this time, I suspect either the ECM or the VP44 but since you guys are the pros, I leave it to you.  Call if you have any questions.  VP44 is the 3^rd one, about 9 years old with 110,000 miles.  ECM was replaced about 5 years ago with a rebuild.

 

Thanks You,

 

Dan Knoch"

 

 

 

 

Also, the truck will only have these symptoms one per start.  Once running, it runs fine.  If it starts without an issue and drives 300 yards without an issue, it will be fine until the next time I try to start it.  A second Service facility had the truck for 3 weeks, replaced the VP44 without resolving the problem.  

 

Mopar1973Man advised to test the Alternator for AC voltage and have the ECM tested.  I will advise what I find.

 

Thanks,

Dan

[Mopar1973Man]

We had a wonderful conversation about this and the strange thing is the VP44 is already been replaced and still acting up. 

[diesel4life]

Dan lives near me and I suggested a shop (Action Auto) that I have dealt with before when my PCM went bad. If I remember correctly they had the truck a few days and felt like it could possibly be the ECM but weren't comfortable enough with the diagnosis to spend his money on a guess. This is where having a spare ECM out of a similar truck would be handy as heck. A quick swap would confirm/deny this. He's covered nearly all the bases up to this point including the 2nd shop throwing a VP at it, I'm not real sure what else it could be.

JR

[Yankneck696]

Could it be something in the ignition switch, by chance?

 

Ed

[DanKnoch]

Hi guys, Thanks for helping me out.

 

No updates yet, going on Tuesday to pick the truck up.  I thought and pondered the ignition thing for a little while, however, when it stalls, all the accessories stay on.  I would think those would die, too.  I am thinking when I get it back, maybe pulling the ECM and putting it in the freezer (am sure the wife will love that) and plugging the block heater in.  In the past it has always started fine with the block heater plugged in.  If it gives me trouble with a warm block and cold ECM, 100% the ECM.  I am somewhat afraid sending the ECM out for testing won't be conclusive since the problem is intermittent and temperature related, any suggestions.  Mopar1973Man, you mentioned Klein-Bottle computer when I spoke with you on the telephone, I have read mixed reviews on them, do you have any personal experience with them?  I know not to believe everything I read online.

 

Thanks again,

Dan

[Yankneck696]

There are several circuts in the ignition switch. Look at the schematics for it in the FSM & you may decide to look into it further.

 

Ed

[Mopar1973Man]

There are several circuts in the ignition switch. Look at the schematics for it in the FSM & you may decide to look into it further.

 

Ed

 

Here is the Dodge FSM for your truck.

http://forum.mopar1973man.com/index.php?/files/file/68-2002-dodge-ram-fsmzip/

[DanKnoch]

Thanks, I could not get the FSM to download.  I downloaded the manual and the WinMD5.  When I try to put them together, it tells me I have the wrong verification number.  I may be doing it wrong, haven't had the best luck with computer stuff lately.

 

Thanks

[DanKnoch]

Just an idea, Would it be possible that the issues are in the relay box???  Relay struggles to contact at 12v but works well at 14v when the truck is running.  Could also explain the stalling which seems to only happen when the grid heaters drop the voltage down.  The fuel pump relay would be the only one that could cause this since I don't have a security system to affect the ASD relay, right.  I have replaced a couple of relays and moved some around with no cure.  

Edited April 6, 2015 by DanKnoch

[DanKnoch]

OK, got the truck back, not fixed.  Truck sat in the drive for a few hours, had trouble starting.  Unable to do too much since the kids are sleeping and the truck is quite loud.  Clue: noticed that when I cranked the engine and it stumbled, I let up on the started but kept the ignition on.  The lift pump stopped as is things were shut down.  If I crank the started any other time and release it without starting it, the lift pump runs for a little while, 25 seconds I believe.  Also, checked power at the VP44 harness and it was good, ignition on and cranking.  Also, very little current through pin 5, the shut down pin, until I turned the ignition off, then 12v for 2 seconds.  The schematic shows everything, ignition too, controlled by the ECM which also controls the lift pump.  Any thoughts???  More testing to follow when I do not have to fear waking the kids and angering the wife.

 

Thanks for the help, 

Dan

[DanKnoch]

What is the knock sensor rtn???  does it do anything  Pin 33 on the ECM, pin 5 on the VP44.  I am suspicious of this and will keep and eye on it.  

[Yankneck696]

We have no knock sensor on our trucks. I still say to investigate the ignition switch.

 

Ed

[DanKnoch]

I am definitely with you on the ignition system, maybe not so much the switch as everything else stays on unaffected.  Is there a good place to probe for power from the ignition to the ECM?  Where does the wiring off the ignition split between the PCM and ECM or is that right at the switch?  How would the block heater make this not be affected?  And why only once per start?  Coincidence???  Ignition circuitry inside the ECM perhaps?

 

Thanks a ton for the help and suggestions.

Dan

[Mopar1973Man]

http://forum.mopar1973man.com/index.php?/topic/9875-2002-hard-start-occasional-stall-not-fuel-related-this-time/#entry109134
 

 

Thanks, I could not get the FSM to download.  I downloaded the manual and the WinMD5.  When I try to put them together, it tells me I have the wrong verification number.  I may be doing it wrong, haven't had the best luck with computer stuff lately.

 

Verified the file on the server is still good and functional. It must be something anti-virus or Windows wise causing your problem.
 

 

How would the block heater make this not be affected?

 

Possible that the ECM tables are screwed up  and the data for cold coolant and IAT temps are screwed up. Possible there is a cracked solder joint maybe causing issues and does better when its warm.

 

 

2002-Dodge-Cummins-power dist.pdf

[DanKnoch]

Thank you for the info. I am not very good at reading those, but based on page 3, can I safely conclude that the fuel pump relay should have power to it whenever the ignition is on? I have worked on small engines that would turn off or not start as a safety if it read no oil pressure, I have good readings at the dash, could it be something like that? Also, 1 of the pins to the VP44 enegizes to turn off the engine. Is there any good place to probe for this with out pulling the harness? Tried checking the other evening and everything looked fine. Had a mechanic, friend of a friend, suggested the coolant temp sensor. Stated mixed readings may cause it to confuse the ECM and shut down. The gauge however reads good, unless for a split second at starting it goes nuts, hard to tell. Spoke to a computer remanufactuer, they said if I purchase an ECM from them and it does not correct the issue, they would refund the the money minus shipping and a $75 test fee. I am a little bit afraid to send the current ECM in for testing for fear of it falsely testing OK due to the inconsistancy of the problem. The past couple of cold starts have been without incident, has had problems after sitting for an hour or 2 and cooled down a bit.

Thanks again for the help on this issue.

Dan

[DanKnoch]

OK, did some messing around and found when the truck stumbles while trying to start, that I am getting a voltage spike at pin 5 to the back of the VP44 harness.  It spiked and went away faster than my meter could keep up, but I hit over 3 volts, probably more, meter reacts kinda slow.  When I started cranking again, there was next to nothing in millivolts and it fired right up.  I ordered the ECM I posted about earlier, didn't seem like too much to lose.  Have good power to the VP44 harness whenever the key is in the run position.  I heard I could cut the wire, but I don't really want to band-aid fix it.  Is there an easy way to pull that wire from the harness to test run without it, I can't seem to find images of the loose connector terminals or the cummins tool to do it.

 

Thanks,

 

Dan

[Mopar1973Man]

Ok. The lift pump should not run all the time with the key on. The lift pump only runs if the crank sensor detects RPM's then it activates and shuts down after loss of RPM's. This is a safety thing.

 

As for the VP44... Here is the wiring diagram. As for the ground that is the battery cable not anything tied to the body or frame.

[DanKnoch]

Thanks, I have studied the wiring diagram. Lift pump runs for a short burst when the key is turned to 'run'. If I bump the starter, lift pump runs for 20 seconds or so. When the truck is having it's problems, try to start it, it fails to start, back the key from the start to run position, lift pump runs for a very short burst and stops. Seems the ECM is shutting everything it controls off. Heard I could cut the 'shut down' wire to the VP44 but I hate cutting things. Any idea how to pull the wire and connector terminal from the harness? Tried a hollow piece of brass tubing down around the outside of the terminal with no luck.

[Mopar1973Man]

Just probe the wire with a test light to see whats going on.

[diesel4life]

Any updates?