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Discussion Starter · #1 ·
I bought a 98.5 24V couple days ago and it has a few weird issues. Pretty sure some kid had it before the person I bought it from. There was a couple amps and random stereo parts everywhere. Also a hot wire coming off the battery that was just hanging out under the rear seat.
That said everything has been fine the last few days. Then today it started having a weird issue like its in limp mode.
The oil pressure, coolant temp, and tach sensor stopped working. It also started feeling like it was in limp mode. Wouldnt go above 40mph and would sputter. Also got a Poooo code in the milage window. Looks like and the guy said it has a new VP44 pump on it. Also found this sheet tucked under the carpet. Any thoughts?
 

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Yikes...

P0000 means the PCM detects a problem but doesn't know what it is. Sorry, but I'm pretty sure the PCM is toast.
 

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The 40mph problem getting up to a specific speed and then just loss of power not able to gain anymore speed along with the rpms not getting above 2k is EXACTLY the problem I had when I bought my 98 12v back in january.

Fix for this was:
Drilled 1/4" hole in bottom of tank and after 4hrs of draining 30gals i put a self tappin machine screw with a rubber washer and some tank sealer to seal it back up.
Added Clear Diesel Additive from Power Service (Tank cleaner / water seperator)
Replaced Fuel Filter
Replaced Fuel Pre Screen (One that is next to the lift pump that is below the fuel heater on 12v)

You have some air heads that think once the WiF light comes on you can just drain the water out of the fuel filter housing and not replace the fuel filter. Well once water hits the DIESEL fuel filter it limits the Diesel that can pass thru it even after draining the canister.

After the above I went from 6-10 pounds at the Injection pump to 15-20 pounds.

Ive also read that some people put a lock up switch for there converter to aid in that issue depending on the job they are doing.

I would highly advise to put a fuel pressure gauge on your fuel filter to injection pump line. I bet your not even getting 10pounds of pressure after the fuel filter.

Trans/Boost/Fuel Pressure & Trans Temp gauges even thou they cost nearly $500 with me installing them, they have saved me already 2 possible tow bills.
 

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Discussion Starter · #6 ·
Thanks for the response. Where would i put a fuel psi gauge on this one? And why does it look different then all the ones i see on 24v fuel psi videos?
 

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Don't start replacing parts and computers with out a lot more diagnosis an clean up. Secone 98.5 to 2000 do not give codes in the dash. It will only do a cluster test. You have go get a scan tool and pull codes with that every time. Deos not have to be an expensive one.start by down loading a wireing schematic. Then Thoroughly clean all battery terminals an cables and and check harness plugs for corroded pins. Remove all non factory unused wiring except certain ground additions. Take itall out and leave onluy clean working wiring. Do an apps reset. Check alt DC ouitput and also AC output lervel. DC shouoldba be about 14v and AC should be under .03 to .05v AC. If you do ont understanjd what I am talking about as far as AC ;let me know later.

Start there and get back before all other. Things are not half as bad as you think damage wise but may be a bit complicated.
 

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Thanks for the response. Where would i put a fuel psi gauge on this one? And why does it look different then all the ones i see on 24v fuel psi videos?

Mine is permanent fuel pressure gauge i installed on the dash pillar. The (aftermarket)fuel pressure sensor is on the injection pump side of the line that goes from that fuel filter housing to your vp44. The threaded set of connections replaced the original banjo bolt that was thread into the injection pump.

Ontop of your fuel filter housing (The picture from your last post) there are 2 lines that come in. One on the right goes to your lift pump which is your supply line on that housing. The one on the left with the Eiffel Tower banjo bolt assembly goes to your injection pump. If you rent a gauge say from Autozone etc the smaller bolt head ontop of the left outlet should unscrew(Bleeder Bolt "Just like a brake line caliper") to allow you to connect a rented mechanical fuel pressure gauge.

Remember i have a 12v so it might be different however you have the exact same fuel filter housing I have even with yours being a 24v.
98 Dodge 5.9L 12v 2WD P7100 Injection Pump

I also completely agree with bigfish's reply above regarding your electrical.

Might be a stupid question but have you checked your cab & engine bay fuses?
 

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You can screw in a gauge fitting in the pipe plug in top of the filter housing. Most problems are electrical some way. Pull codes with scan tool.
 

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Also why does my fuel filter canister look different?
That is the correct filter housing for an early truck. After 99 (I think) they switched from the aluminum one to the cheap plastic one.
 

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Thanks for the response. Where would i put a fuel psi gauge on this one? And why does it look different then all the ones i see on 24v fuel psi videos?
Looks like there was a gauge on it at one time by the looks of that brass doohickey on top of the out going banjo bolt. The 2 brass plugs on top are test ports. My gauge is screwed into one of those. I believe (I have to look to be sure) the one behind the wires in your pic. is the post filter port which is the one you want.
 

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Discussion Starter · #12 ·
Thanks for all the info and help everyone. I really appreciate it.
I havent done anything with it yet. But just like all the previous days it cranked up and has been driving just fine all day. The problems i got arrose right after i pressure washed the truck.
The guy before me said it had a previous pcm problem and got the codes i showed on 12/5/2020.
Either way Im sure i still have work ahead of me.
 

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Discussion Starter · #13 ·
Ok so for this on going sogga ive learned a few things. 1 that i have a brand new fuel pump, filter, and fuel overflow valve. Im getting 14-16psi at idle and im dropping down to 9psi when i accelerate. So with this information and with the knowledge that this is an acceptable psi range. Im now moving on to the next stage. Electrical. Does anyone know if a bad and or just a PAC ECM bypass would cause these issues? I also go this code and limp mode today after driving for a bit and knowing that my fuel pressure is good. It only happens once the truck is warm. If its cold outside I can floor it multiple times before it goes into limp mode. When its hot I can do it once. I also have a edge insight CTS2 that I was able to read RPMs with. But my dash doesnt show it.
 

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What is a PAC ECM bypass? Codes are no shown on a 98.5 or 99 with the key trick. Use a scan tool on the obd port. With electronics mods it is hard to tell. On stock trucks and most modded ones the Crankshaft position sensor shows in tach and running issues. Replace it.
So pull codes and replace the crank sensor(beside the starter). If that is not successful put other things back to stock and see if mods are causing the problem.
 

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Discussion Starter · #15 ·
Well today was an interesting turn. Found a loose terminal clamp on the pass side. It was cracked and shaking. I got it swapped out and tightened. Now my brake light and abs is always on and the wait to start light comes on every time.
So after that i got it warmed up and got in and drove it around. Was fine at first but then I floored it and the damn thing tried to run away from me but kept sputtering at the same time. Even with my foot off the throttle. Turned it off and started it back up. Ran like it had a dead pedal and would sputter rev for a bit. Then parked it and it would randomly rev up while idling and sputter and go back to idle withing 2-3 seconds.... WTF??
 

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Pull codes again with a scan tool and see what you have. Then clear and drive again at least 5 starts and stops.and pull again. Recheck rest of cables. What is maximum rpm now?
 

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Discussion Starter · #17 ·
What is a PAC ECM bypass? Codes are no shown on a 98.5 or 99 with the key trick. Use a scan tool on the obd port. With electronics mods it is hard to tell. On stock trucks and most modded ones the Crankshaft position sensor shows in tach and running issues. Replace it.
So pull codes and replace the crank sensor(beside the starter). If that is not successful put other things back to stock and see if mods are causing the problem.
 

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Discussion Starter · #18 ·
Pull codes again with a scan tool and see what you have. Then clear and drive again at least 5 starts and stops.and pull again. Recheck rest of cables. What is maximum rpm now?
Not sure what maximum RPM is right now. Ill have to hook up my cts monitor to check. Ill do all that when I get back home. Thank you sir.
 

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If it is not going over 1600-2600 and doing the other things you describe it is a bad VP.
 

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Discussion Starter · #20 ·
Mine is permanent fuel pressure gauge i installed on the dash pillar. The (aftermarket)fuel pressure sensor is on the injection pump side of the line that goes from that fuel filter housing to your vp44. The threaded set of connections replaced the original banjo bolt that was thread into the injection pump.

Ontop of your fuel filter housing (The picture from your last post) there are 2 lines that come in. One on the right goes to your lift pump which is your supply line on that housing. The one on the left with the Eiffel Tower banjo bolt assembly goes to your injection pump. If you rent a gauge say from Autozone etc the smaller bolt head ontop of the left outlet should unscrew(Bleeder Bolt "Just like a brake line caliper") to allow you to connect a rented mechanical fuel pressure gauge.

Remember i have a 12v so it might be different however you have the exact same fuel filter housing I have even with yours being a 24v.
98 Dodge 5.9L 12v 2WD P7100 Injection Pump

I also completely agree with bigfish's reply above regarding your electrical.

Might be a stupid question but have you checked your fuses
yes sir I did. They all lit up like they were good.
 
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