Can the idle speed be adjusted?

[SASQCH]

Can the idle speed on a 24 valve 2nd gen cummins be adjusted? If so how? My truck idles at 740-750 rpm, I would like it to idle around 800 rpm so it don't die when shifting into drive. The truck has a Low Stall TC and it is causing the truck to die when shifted into drive. If I hold the rpm to around 800 it don't stall. Does it warm or cold. Yes, fuel pressure is there (17.5), CKP was replaced 15 months ago, IAT and MAP are new, grounds and batt connections are clean and tight, batteries are well charged, alt is putting out 13.58 volts at the batt. See this thread for history: http://forum.mopar1973man.com/showthread.php/1584-Problems-Stalling-when-shifting-to-drive-and-hard-starting-when-hot.-Ideas Thanks Jim

[Mopar1973Man]

You could crank up the APPS sensor but now you'll have problems with the idle validation switches... So I not sure how you would get it idled up more without making a new problem... Vp44?

[SASQCH]

You could crank up the APPS sensor but now you'll have problems with the idle validation switches... So I not sure how you would get it idled up more without making a new problem... Vp44?

VP44 was replaced in AUG 2007 and has always had at least 13 psi fuel pressure and 2 cycle oil.

Mike, you said in my other thread (Problems - Stalling when shifting to drive and hard starting when hot. Ideas?????) on this issue and other issues that have been fixed, referring to my idle speed of 745 rpm "The idle speed is low compared to mine at 880 RPMs and factory setting or programming is typically 850 RPM."

What did you do to get your idle speed up that high and how did you resolve the issues with the validation switches?

Thanks

Jim

[Mopar1973Man]

That's the problem if you increase the signal voltage out of the APPS the voltage would most likely cross the printed voltage on the APPS if your stock. So this would trip the switches to reverse (off idle).

I'm wondering what your at for voltage now (APPS Signal) and what you APPS voltage is on the tag?

http://forum.mopar1973man.com/attachment.php?attachmentid=699

[SASQCH]

That's the problem if you increase the signal voltage out of the APPS the voltage would most likely cross the printed voltage on the APPS if your stock. So this would trip the switches to reverse (off idle).

I'm wondering what your at for voltage now (APPS Signal) and what you APPS voltage is on the tag?

http://forum.mopar1973man.com/attachment.php?attachmentid=699

OK. The APPS data sticker says it should read 0.633 volts it reads 0.334.

I found installation instructions for the apps sensor that says this about the idle adjustment screw.

"Using a digital voltmeter, set the idle voltage by adjusting the idle stop screw. This screw also has Loctite on it from factory, so make sure the T20 torx bit is fully engaged into the head before attempting to turn it. If you think it may strip, carefully heat the screw area with a propane torch. This will soften the Loctite and allow it to turn. Only heat it for a couple of seconds at a time and attempt to turn the screw clockwise. After making the screw turn, measure the voltage. Plug the sensor into the factory harness. Using the paperclip provided, insert it in between the orange seal and the green wire on the back of the APPS connector. Push it in until it stops. Or you can measure the voltage on the blue wire with a black tracer in the factory plug, the same way, whichever is easier. Make sure the paperclip does not contact ground and then turn the ignition key to the ON position. Turn your voltmeter to the low voltage DC scale. Now read the voltmeter, it should read .60 - .67 volt. If it reads higher than that, turn the idle stop screw counter clockwise until the voltage is below .60 volt. Turn the idle stop screw clockwise until the voltage begins to rise, then turn the screw counterclockwise 1/2 turn and you are done with the adjustment."

I tried the adjustment. I think my APPS is bad.

When I try to turn up the voltage with the idle screw (clockwise) it don't change for several turns then it suddenly goes to 0.018. If I try to go the other way it goes to 0.334 again and don't change after that regardless of how far ccw I turn the screw.

I'm suspecting that is the cause if the 750ish idle speed and the stalling when going into drive.

I'm going to replace it with a timbo from JKIDD.

[Mopar1973Man]

You are one of the few people that was lucky enough to fail within specs and not toss codes... .334 is a bit low for volatage typically idle is right around 0.5 volts... So I can see that causing issues with idling lower. So yeah it's time to think about replacing the APPS sensor...

[SASQCH]

Jacob is usps overnighting it to me so hopefully it will be here tomorrow. I will post how this all turns out.Hopefully, it will fix the issues I'm having.Thanks guys for all the help, both here and on the cummins forum.I typically post the same thing in both forums, surprising how the advice differs.

[JOHNFAK]

I typically post the same thing in both forums, surprising how the advice differs.

Yeah you caught me once on that already. Subscribing to this also.

[SASQCH]

Got the Timbo APPS today. Took me all of 15 minutes to install and set. Instructions are included as well as a torx screwdriver bit. Did an APPS reset. Truck starts and runs, idle speed hasn't changed.Still stalls when shifted into drive. :banghead:

[ISX]

Crazy thought here, I have no idea what exactly initiates when the orange needle hits the "D", but is there any way it could do something to drain the voltage for a second that makes it pull voltage from the VP and it trips the low voltage threshold for a second, enough to make the VP give up for a second, which is enough to kill it? I don't know how the power gets fed through the VP and trans but maybe the wire is too small and the thing in the trans sucks a lot of volts, which is why revving it up a little keeps it running. I am thinking it just barely hits that threshold, so revving it up gives it another 0.1V that is just enough to keep it running. I don't know if it all feeds back to one small wire that would be susceptible to a voltage drop like that though. I know, crazy, but I been trying to think way outside the box on this one, since all the ideas inside the box haven't worked.

[SASQCH]

Crazy thought here, I have no idea what exactly initiates when the orange needle hits the "D", but is there any way it could do something to drain the voltage for a second that makes it pull voltage from the VP and it trips the low voltage threshold for a second, enough to make the VP give up for a second, which is enough to kill it? I don't know how the power gets fed through the VP and trans but maybe the wire is too small and the thing in the trans sucks a lot of volts, which is why revving it up a little keeps it running. I am thinking it just barely hits that threshold, so revving it up gives it another 0.1V that is just enough to keep it running. I don't know if it all feeds back to one small wire that would be susceptible to a voltage drop like that though. I know, crazy, but I been trying to think way outside the box on this one, since all the ideas inside the box haven't worked.

Interesting thought I'll have to mull that one over for a while. I'm wondering if it may have to do with the quality of diesel we get here in Alaska. When I added injector cleaner (which lowers the flash point of the fuel) the stalling went away. Next week I'll be traveling to Montana and back with a load each way. I'll see if the fuel difference along the way makes a difference. Thanks Jim

[ISX]

That thing drives me nuts. The little things that fix it that never seem to relate to each other. I don't know if the fuel has anything to do with it because you say it only does it in drive, and it runs fine idling nonetheless. Yet injector cleaner fixed it. I'm more curious how it stalls. Like does it just stop instantly or is it more of a smooth stop like you just turned the key off? How long after you put it in D and feel and it shift into gear does it happen? A video would be better but I know that can be a hassle. A good description of how it dies, when it dies after you feel it drop into D, and such would be good. Does it do it religiously or only when conditions are right? If it doesn't do it constantly, how often? Did the injector cleaner fix it through the whole tank of it, and did it screw up on the next tank?

[SASQCH]

That thing drives me nuts. The little things that fix it that never seem to relate to each other. I don't know if the fuel has anything to do with it because you say it only does it in drive, and it runs fine idling nonetheless. Yet injector cleaner fixed it. I'm more curious how it stalls. Like does it just stop instantly or is it more of a smooth stop like you just turned the key off? How long after you put it in D and feel and it shift into gear does it happen? A video would be better but I know that can be a hassle. A good description of how it dies, when it dies after you feel it drop into D, and such would be good.

You can see in the video when I send it to you or can get it posted here.

Does it do it religiously or only when conditions are right?

It's a rare occasion that it doesn't die. It has died going into reverse but thats like 1 out of100 times it dies in reverse.

If it doesn't do it constantly, how often?

It's like 1 out of 100 that it doesn't die going into drive.

Did the injector cleaner fix it through the whole tank of it, and did it screw up on the next tank?

Yes, worked for the whole tank then started dieing again when the cleaner was used up and fresh fuel added.

Just took a video. I don't know how to post a vid on this site.

PM me your email and I'll send it to you.

http://s1015.photobucket.com/albums/af273/jimbowe43/videos/?action=view&current=985Dodgedieseldieswhenshiftedintodr.flv

[ISX]

Now that is weird. It's just like D is the fuel shutoff solenoid. I can't figure out what you are doing to get it into D to keep it from dieing. You put it into D right after it starts as fast as you can and it doesn't die? I don't think fuel would have anything to do with that, I mean why would it run perfect and go in reverse fine and then D is like the fuel just gelled instantly, but it obviously fixed it so I'll keep thinking.

[dually]

I think you have a dead short.Do you use your tilt wheel alot? Something is shorting out.I did see your volts go down with the heater grid.What happens when you go from park to 1st gear do it fast.Reverse to 1st fast.Then try it slow.It seems like drive hits the ecm shutoff wire.I would dig into the column.

[SASQCH]

Now that is weird. It's just like D is the fuel shutoff solenoid. I can't figure out what you are doing to get it into D to keep it from dieing.

You put it into D right after it starts as fast as you can and it doesn't die?

That's correct.

I don't think fuel would have anything to do with that, I mean why would it run perfect and go in reverse fine and then D is like the fuel just gelled instantly, but it obviously fixed it so I'll keep thinking.

If you listen real close when it starts, it takes a second or so for the engine rpm to stabilize to the idle speed of 750ish rpm. If I shift it before the rpm settles down, it doesn't die. If I wait a second or two before the shift it dies.

I don't plan to do anything more to solve this issue until I get back from Montana in about 3 1/2 weeks, don't have time right now. I'll see what happens on the trip with fuels through Canada and Montana.

[Mopar1973Man]

Way you VP44 is acting you might talk to JL Welding... Seems you to got something in common... But that is plain weird everytime you hit Drive (in gear) it falls on its face and dies not unless you jump into gear rapidily... It like the governor of the VP44 isn't doing its job properly is my feeling... Because the unstable idle isn't right nor is the low idle speed... Something is for such not right...

[ISX]

If you listen real close when it starts, it takes a second or so for the engine rpm to stabilize to the idle speed of 750ish rpm. If I shift it before the rpm settles down, it doesn't die. If I wait a second or two before the shift it dies. I don't plan to do anything more to solve this issue until I get back from Montana in about 3 1/2 weeks, don't have time right now. I'll see what happens on the trip with fuels through Canada and Montana.

You've answered everything I have wondered about it. I got some ideas but that injector cleaner is throwing all of them off Oh, on what Dually said, whats the answer to that? About putting it in 1st or 2nd going past D real fast, does it still die?

[SASQCH]

You've answered everything I have wondered about it. I got some ideas but that injector cleaner is throwing all of them off Oh, on what Dually said, whats the answer to that? About putting it in 1st or 2nd going past D real fast, does it still die?

I tried that a few times and yes it still dies. Throw your ideas out here, they may spark other thoughts if nothing else.

[jetz]

my truck does the same thing but only when the a/c is on any thoughts