Dodge Cummins Diesel Forum banner

1 - 20 of 48 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
I have a 98.5 24v. I’ve read the dead pedal threads but my issue seems different. On occasion, I’ll have no throttle response but only after starting the truck. It hasn’t happened driving down the road. And if I shut the truck off and restart, it usually works fine. I do have the P0122 code (I believe) low voltage for Apps. Anyone have any idea? The APPS was replaced not long ago. Thanks
 

·
Registered
Joined
·
7,723 Posts
The codes need checking with a code reader to see if anything else is going on now.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #3
I got the P1693 and the P0122. I just adjusted it to show .60 volts so we’ll see if that helps
 

·
Registered
Joined
·
19,156 Posts
.60 output on #3 wire is not the one being measured, but it is the idle voltage. It should actually be about .5v, under .529, unless you have a Timbo, and if so that may be he problem.
Low voltage to sensor is the input and should be 5 volts on a different wire. Occasionally the problem is a bad APPS. More often it is dirty corroded, even mildly, battery terminals(often driver neg) or cables. Clean all terminals for perfect metal to metal connection and check cables for corrosion.

Do you have a Timbo apps, the one with a pigtail hanging down 2"?
They are especially an issue on 98.5 and 99 trucks casueing the truck ECM to think it is accelerating when it is not, surging at idle and other wise sometimes.

Also does the tach always look like it is accurate, not bouncy or low? If either you have a bad Crankshaft sensor.

The truck starts and runs for about 5 seconds from a computerized Crank signal for timing, the the sensor takes over. Does not sound like your problem, but.

It could be an ECM problem. What does the wait to start light do when you turn the key to ON? Does it always come on for at least a second?
 
  • Like
Reactions: Clunk

·
Registered
Joined
·
83 Posts
I just replaced the batteries 2 weeks ago but I'll check the cables. I don't have a Timbo. The tach looks accurate, however I've had an issue with the truck loping on first start up and then dying. It's not every time and I've never had dead pedal while driving. Only on start up. The wait to start always lights, sometimes it seems like its on for too long, but it's been a while since I've been in a 2nd gen so maybe not. So I should adjust the number 3 wire down to .5? Thanks for your time and trying to help.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #6
Sorry for any confusion, I see sometimes this logs me in as NukeBrigade, other times as Eric. They are both me.
 

·
Registered
Joined
·
19,156 Posts
Just close the Nuke account becasue you have more posts and privileges on Eric. Send a note to admin if you have to.
 
  • Like
Reactions: Nukebrigade506

·
Registered
Joined
·
19,156 Posts
Couple of ways but best is to upload a link.(cut and paste to body or upload box below.) Yours will have to be approved by Admin before it will post becasue you are a newbie. May take a couple of hours or couple of days.
 

·
Registered
Joined
·
14 Posts
I haven't had a chance to look at the responses but have checked the lift pump? I always look at ground connections too but this sounds like it's starving for fuel.
 

·
Registered
Joined
·
7,723 Posts
I know it's not acting right but that lope sounds wicked.
 

·
Registered
Joined
·
83 Posts
Haha, yea it does! And I haven't checked the lift pump, it does have a FASS150 on it and I can hear it running. I'm going to check the grounds and replace the fuel filters this weekend. I left it parked for now. Hopefully I can get it figured out before it snows again.
 

·
Registered
Joined
·
19,156 Posts
That looks like either and air fuel leak letting air into the VP or a bad Crankshaft sensor. If it repeats that way right after the first try it may be the crank sensor. If it won't start and needs bleeding it is air. It could also be a leak on top of the fuel filter canister at the heater wire plug which will often auto bleed from the lift pump..

If you have any fuel pressure it is not the lift pump. If you do not have a gauge loosen the pipe plug in top of the filter housing and hit the "starter bump" and listen for the lift pump and if it runs and see if it runs while running.
It is strange that you do not see the tach drop but it does acta lot like a bad sensor. Timing is sete by ecm first 5 seconds and then it is supposed to switch over to sensor. That is when it dies(assuming fuel is correct.)
 

·
Registered
Joined
·
19,156 Posts
Wait a minute, why did you cycle the key twice? Does the wait to start light come on with the key every time?
 

·
Registered
Joined
·
83 Posts
It can repeat 10 times, or start right up the first or second time. There's no real pattern to it. I cycled it twice just because it was like 5 degrees and windy that morning. I've read a lot of posts about the crank sensor. I'll give that a shot this weekend too. Thanks for all your help.
 

·
Registered
Joined
·
83 Posts
Pulled codes again today and it looks like you are probably right, P1690 showed up. I’ll be changing the sensor tomorrow. Should I go with Cummins or are other sensors ok?
 

·
Registered
Joined
·
19,156 Posts
Either is fine so long as it is the good/best name brands, NO second or third brands. Wells Stewart Warner, Standard, Bosch, Duralast, Autozone. etc. NO Chinese substitutes.
 
1 - 20 of 48 Posts
Top