[Stephenopolus]

1998.5 Ram 3500, 4x4 dually, 5sp 259k miles
lift pump was replaced with oem version about 50k miles ago
all filters are currently due to be replaced but I am holding off on the fuel filter so as to not mess with whatever pressure there might be until I am sure the lift pump is working.

Light normally comes on either at key turn or after key turn and diagnostic test finish.
But light and lift pump always come on at same time until 2 days ago when both stopped coming on.
Still starts within one or two revolutions
Little puff of smoke at start but not white then normal exhaust
Runs and drives like normal.
There is a leak around the top of the fuel tank that has been there for a couple of months. I just haven't replaced the gasket yet.
I am concerned that I can no longer hear lift pump working and light not telling me the intake heater is ready.

I want to drive it to autozone in the morning to try and get codes since the key trick (on, off, on, off, on) doesn't seem to work. (truck might be too old for key trick to work although it worked on my 95 intrepid)

UPDATE: Just got back from Autozone and Advanced Auto. Both stores connected code reader. Both stores said "No codes showing"

QUESTIONS:
How long can I drive it this way before it ruins the injector pump?
Is there a chance that the lift pump is still good but not coming on until after start?
Is there a relay that controls the lift pump or is that controlled by the ecm?
Will the lift pump cancel the light from coming on and the intake heater still be working or visa-versa?
Could this problem be from the leak around the fuel tank top even though I have driven it for a couple of months with the leak (I have been putting in 5 gals of fuel at a time)?

Lots of question I know. Thanks for your help.

 

[5.7 Hemi]

I think the “wait to start” is for the grid heater. Check on that.

 

[bigfish95971]

Long and short of it is you ECM has failed. Porbalby has 606 or 602 code. But your symptoms are definitive of ECM failing to boot up and power systems, Replacement needed. Sometimes caused by damage from AC from the alternator, so that needs to be checked too. Damage is not reversible.

 

[Stephenopolus]

Long and short of it is you ECM has failed. Porbalby has 606 or 602 code. But your symptoms are definitive of ECM failing to boot up and power systems, Replacement needed. Sometimes caused by damage from AC from the alternator, so that needs to be checked too. Damage is not reversible.

Just got back from Autozone and Advanced Auto. Both stores connected code reader. Both stores said "No codes showing"

 

[Stephenopolus]

I think the “wait to start” is for the grid heater. Check on that.

Grid Heater is the intake heater. Same part different name.

 

[5.7 Hemi]

Right.

 

[me78569]

the Wait to start light that comes on for a split second on key on is the ecm boot start notice.

Think of the wait to start light like this screen for a computer, but for the ecm.

no Wait To Start upon key on either means the bulb in the cluster is burnt out, which has it's own code, or the ECM is failing.

 

[bigfish95971]

Contact ACS on here and send it to them for testing and repair or replacement.

 

[Stephenopolus]

the Wait to start light that comes on for a split second on key on is the ecm boot start notice.

Think of the wait to start light like this screen for a computer, but for the ecm.
View attachment 965951


no Wait To Start upon key on either means the bulb in the cluster is burnt out, which has it's own code, or the ECM is failing.

"wait to start" light on my truck has never been a split second, It normally lasts from 2-6 seconds depending upon how cold the temperature is. Originally I thought it was the glow plug warmer but I have been told by a diesel mechanic that it is on when the engine is off and the grid heater is warming for prestart.

 

[me78569]

Key on should flash the wait to start regardless of outside temp or grids.

That's the boot notice of the ecm

 

[Stephenopolus]

UPDATE:

Out of desperation I started pulling and visually checking fuses to see if I had one blown. In the box under the hood there are two 30 amp fuses. One labeled "ignition run" and the other labeled "Engine Control". I took those out and swapped their location with each other and everything started working again. So, I thought it might be a blown fuse and I double checked by putting them back in their original locations. To my surprise. everything still worked and has kept working all day today.

I did put a trickle charger on the batteries this morning and it was showing "charging" the whole time but other than that the only thing I did was unplug and reinsert fuses.
I wonder if the alternator did spike ac for a second, just enough to scramble the settings but not destroy it, and then when I pulled the fuse and re-inserted it, the ecm reset.
Thinking that might be it, I took it back to autozone and had them test the charging system. The guy told me both batteries were getting 12.4 amps to them which he thought was a bit low for charging but his numbers were for a one battery system.

Another thing I just remembered was that a couple of days before all this started, there was a noticeable draw and release on the electrical system much like the alt is going bad or the ac compressor was kicking on and off. AC was not on. Alt was replaced in 2017 with an orileys lifetime one. (Probably means cheap Chinese one).

I think I might need to take it to someone with a better testing set up and get the alternator checked before the voltage regulator it goes out and fries the ecm. I might just be on the very start of a big problem if I don't find what caused the need for the ecm to need a reset, if that is what I inadvertently did. Anyone think I am on the right track or have I missed something?

 

[Stephenopolus]

Key on should flash the wait to start regardless of outside temp or grids.

That's the boot notice of the ecm

It does even in the summer. It stays on as long as the lift pump is running. But in the winter it stays on long after the lift pump stops.

 

[bigfish95971]

The lift pump should not be running unless you bumped the starter. maybe the fuses had a little corrosion and bad connection on the spaces.

 

[Stephenopolus]

The lift pump should not be running unless you bumped the starter. maybe the fuses had a little corrosion and bad connection on the spaces.

The lift pump always comes on with the "do not start" light when I turn the key to the run position, either right away or just after the idiot lights go out and system check is finished. Been that way since I owned the truck. It primes the injector pump before cranking to reduce wear on injector pump by turning it dry. If I don't start the truck after turning the key to the run position the lift pump goes off after it primes the injector pump usually 2-3 seconds.

 

[bigfish95971]

Yes you will get a 2-3 second run but not sit there and run for longer. Buthe lift pump is onlyh one of several functions of booting up and the others should happen almost instantly and let the truck start and the light gasohol only come on for a second if not cold or under 60* for grid heaters.