Engine/Transmission (1998.5 - 2002) Feeling Lost, major issue (to me)

[bikinjoe]

It seems like I've replaced about everything we can think of for the Fuel system so far. My previous thread helped, or so I thought. https://www.turbodieselregister.com...002/197278-studdering-missing-hesitating.html



Now we've replaced the Injection Pump, added a FASS 95 system to the truck and now it's worse than it ever was.



It's to the point where it is hesitating at almost every rpm now, with the new FASS it got worse, the shop said it's the VP44, took it off, tested it, said it was bad and replaced it, now it's getting worse again.



Before it was intermittent, now it's consistent. #@$%!



So far replaced.



MAP

IAT

APPS

Lift Pump

VP44



I'm looking for some help, the shop seems to be at a loss, Oregon Fuel Injection (which seem capable) can't pull any code, say everything checks out.



Tonight when I drove it home it was fine the first 2-3 miles, it sat for about 1/2hr after the short drive, I got in to drive the rest of the way home and the problem started again. Basically it's a really bad hesitation, like it's starving for fuel, or a bad short, or????



Anyone have any thoughts? suggestions? whatever?



Thank you for any and all help.

 

[JLandry]

bikinjoe,



These are long shots, but worth tossing out...



Have you replaced the air filter through this ordeal? A plugged air filter can lead to low power.



What about replacing the engine coolant temp sensor... have you done that? The ECU does alter the fuel injection based on the engine temp, and what if it's sending some screwy signals I could imagine symptoms like you've been experiencing.



Also, have you tried unplugging and replugging in the ECU connectors a couple of times just to make sure all the pins are making good contact?



Good luck,



John L.

 

[rkressg]

Maybe a bad injector or leaking fuel delivery tube???

I am assuming that you have changed the fuel filter.

Beyond that, you have changed almost all the common culprits.

 

[ThrottleJockey]

Jeez, did you check the old fuel filter or does your FASS have a new larger, dedicated fuel line?

If you plumbed into the stock fuel line, your'e now dealing with pumping fuel through 3 filters.



When I installed the FASS on mine with big fuel line from Autozone, I was finally able to break the tires loose.

 

[JFaughn]

Fuel pressure at VP ?

 

[LowFly]

Whats your fuel pressure doing?

 

[JLandry]

One other idea to check (from the Dodge Powertrain Diagnostic Manual):



Check the power and ground circuits connected to the PCM (Powertrain Control Module). The PCM is located on the passenger side engine compartment firewall and has 3 each 32 pin connectors plugged into it.



To check these circuits, make sure the ignition key is off and the negative batter cables are disconnected (to prevent dangerous voltage spikes from damaging the PCM), then disconnect the PCM connector 1, which is the connector closest to the engine. IMPORTANT NOTE: The PCM receives unswitched power from the battery at all times no matter what position the ignition key is in. This is why you should disconnect the batteries before attempting to unplug PCM connectors.



I'd examine the PCM connector pins carefully to make sure all the pins look good and aren't corroded, etc.



Using an Ohmmeter, verify that pins 31 and 32 of PCM connector number 1 are grounded to the truck body with low resistance. If the pin numbers aren't marked on the connector, the two you're looking for are together on one corner of the connector and both are connected to 14ga Black/Tan wires.



Leaving the PCM connector disconnected and the ignition key off, reconnect the negative battery cables. Check that 12 volts (battery voltage) is present between pin 22 of the PCM connector and a truck body ground. Pin 22 is on the same row and opposite the ground pins mentioned above and is connected to a 14ga Red/White wire.



Now turn the ignition key to the run position (do not start). Check for 12 volts (battery voltage) at the pin 2 of the PCM connector. Pin 2 is in the opposite corner of the ground pins tested earlier and is connected to an 18ga Light Green/Black wire.



Turn the ignition key off, disconnect the negative battery cables, reconnect the PCM connector, and reconnect the negative battery cables.



Even if you don't find anything wrong, it's possible just unplugging and replugging in the PCM connector might help pins make better contact. For that matter, while you have the battery disconnected, you may want to go ahead and unplug the other two PCM connectors, examine the pins, and plug them back in... can't hurt.



Let us know how things progress.



Good luck,



John L.

 

[Chief USA]

Do you know if they by chance replaced the Cam Position Sensor when you had the IP replaced?

 

[aircop]

When you installed Fass pump are you drawing threw stock fuel pickup or have you installed a draw straw. If using stock pickup you may be sucking in air, somewhere.

 

[bikinjoe]

Thanks for all the suggestions so far.

The Cam Position Sensor was not replaced, it was tested with no problems.

Fuel Filter: I'm on the 3rd filter in 1 month, it's the first thing they do when you take it in, it was also the first thing I did...

They did put in a larger fuel supply line, and according the the gauge it is running between 10-12psi, it dropped to 9 when I slammed the pedal to the floor to test it.

It was supposed be checked out completely, Injectors, ECM, PCM, pressure at the VP, etc... and I am pretty sure they checked it out. The shop does a lot of diesel work and I am pretty confident in them. At this point though they seem to want to play a guessing game as nothing is throwing a code.

I have not replaced the air filter for a about 3 months, I'll look at that tonight, I have not replaced the temp sensor either. It's wierd is that it does not do anything wrong until it gets warmed up so you may be onto something there, temp sensors are cheap so I'll pick one up and try it.

I did unplug the ECM and check the connections but have not done anything on the PCM yet.

I am getting a list going, the shop sais they will figure it out for free now, then we'll talk about fixing it...

Thanks again, it's been a lot of good ideas.

 

[aircop]

Just thought of something my truck was running like that the other day. I got a crank position sensor code. Changed sensor that fixed it.

 

[Misenheimer]

Could it be the BIO you are running?

 

[AllianceDiesel]

Did you replace the apps or just adjust it, the reason I'm asking is that the apps isn't adjustable, sounds like you have an apps problem.

 

[aircop]

Apps is adjustabe I can't remember the procedure but it involves a volt meter. You have to set the voltage correctly. There is a set procedure for it.

 

[aircop]

Bikinjoe is the tach jumping around alot when the motor is acting up.

 

[bikinjoe]

I adjusted the APPS, then replaced it, still no go...

The Tach is acting up, in the beginning it was only jumping 50-75rpm, after the FASS it is up to 150-300rpm.

I doubt is the BIO, it is commercial grade and this time of year if I run it, it's only 20% mix with the cold weather. But the last couple tanks where straight from the regular diesel pump.

We are going to try the Cam Sensor, it's pretty cheap compared to the rest of the stuff replaced. The shop has it back in again, the are focused on finding out what is wrong and hopefully done guessing!

thanks.

 

[aircop]

It cost me $60. 00 for the crank position sensor. When it was acting up tach would jump all over. With new sensor tach is steady as a rock never idled so smooth.

 

[dpease]

Would you consider it surging? ToolManTimTaylor had a surging issue about 5yrs ago. When through everything only to find bad battery cables and bad terminals connections causing his problems... . do a search on surging

 

[DMannon]

Are you getting air in the fuel? Pull the fuel line at the filter, or the VP. Run it into a bucket and bump the starter. Is it coming out clean and even, or foamy? Foamy = air entering somewhere. Have you checked the fuel pickup in the tank? Mine was separated and sucking some air when the tank was less than 1/2 full.