VP44 1998.5 Eyes Burning, Bad Mileage Help

[Njbenz]

Need some help.

I’m The second owner of the truck, 175,000 miles. All originally stock, only modifications is an air dog lift pump and a heater grid delete. When I disconnected the batteries to do the lift pump install a few months ago, I did an APPS reset using the throttle pedal.

When I start and idle the truck over the past week, I can smell what seems like unburnt diesel from the exhaust pipe. After a few minutes driving down the road and at a stoplight, before the engine is it operating temperature, I can still smell the rich diesel, and inside the cab my eyes start to burn. No codes are being thrown, no check light is on. I was pulling my boat yesterday, 6500 lbs, and it didn’t seem like it had good power going up a small grade. I am not getting any black, white, or blue smoke out of the tailpipe.

what are the possible issues that I need to check?

[LorenS]

The problem may not be related to the lift pump install. So you have a live data reader of any kind? And at 175,000 miles if your injectors are factory, they may be getting weak and injecting too early. Coupled with a low engine temp and disconnected grid heater, I would think that could lead to unburnt fuel. A map sensor could be lying to the ECM and causing it to overfuel,same with an ECT sensor. This is where a live data reader would come in handy.

[Dieselfuture]

My first thought is injectors also, that or low compression. I'd start with injectors, depending on your goals and go from there.

[Njbenz]

I picked up a live data reader, But it does not auto detect my Vin number. I manually type in my Vin number into the scanner, and it still does not recognize the Vin number. I was able to go into some of the data through the scanner, but it is limited. I can see intake air temperature, manifold absolute pressure, engine coolant temperature, Calculated load value, vehicle speed sensor, etc. just the basic sensors. What should I be looking for, and is it common for the scanners to have a hard time communicating with second GEN Cummins?

[LorenS]

Do the sensor outputs seem to make sense? Like coolant is ambient first thing in the morning, and 180-200 when warm? MAP rise when boost should be coming on?

 

Is engine load at idle and in park/neutral above 0%? Preferably around 5-8%. 

[Njbenz]

I ran it for 3 minutes with the gauge hooked up. IAT and ECT seemed to be close. MAP was 14.8 at idle, and when I put in gear (nv4500) held the brake and put a small load on it, the MAP jumped up to about 18/19. 

[dripley]

This is with the engine off and cold? Cold could be miss leading depending on where you are right now.

[Silverwolf2691]

Just remember to subtract your altitude's air pressure (14.7 at sea level) so ~4-5 psi with that 18-19 psi, if you are at sea level..

 

With pressure gauges, you have 3 types:

psia - absolute pressure, includes the pressure of the atmosphere in the reading. This is what the MAP sensor is reading.

psig - gauge pressure, 0 psi is atmospheric pressure, anything else is above atmospheric pressure. this is what our boost gauges are.

psid - differential pressure, pressure on one side of something against the other side. Usually upstream and downstream of a filter. This is part of how DPFs know when they are getting full.

 

 

[Njbenz]

This is after running the engine for 3 minutes, and with it running at idle. Ambient air temp outside here in NC is 90 degrees today. 

[dripley]

What part of NC.

[Njbenz]

Raleigh. 

[dripley]

I am in Charlotte but live in Hickory. Raleigh is bit out of the way.

 

It is odd to see the ect and iat the same except on a cold startup where they would be the same ormvery close. And the rpm is at 0 if reading the above right. Not sure about reference and value but I am assuming the value is what the tool is seeing. 

 

Do you knowmthe previous owner somyou could ask him ifmthe injectors are OE?

[Njbenz]

I have all the device records from the previous owner, and they are OE injectors. 

[Silverwolf2691]

My brother had a similar issue with the smell and burning eyes with his truck. Turned out his ppump needed an overhaul. Needed machining too apparently. Dont know/remember on what but I think it was in the governor spring area.

 

If the VP44 failed advanced or retarded, not sure which, I think retarded, it could also have the unburnt smell and the lower power like you described. You might have joined one of the unlucky few to have a VP44 fail without a engine code. Depending on the state of your lift pump when you swapped it and if/how long it couldn't produce the proper amount of fuel, it might have munched the timing piston.

 

Injectors are another possibility, popping too low due to wear and tear. When the engine is at an idle can you tell us what the engine load is? It's the readout just above coolant temp in the photo above. At an idle, if its below 5% you should start looking for new injectors. If its around 0-1, you need injectors pronto. the other sign with out the scan tool is your idle speed. If its higher than like 875 ish RPM, the injectors are shot and need to be replaced. This is end stage though, you wouldn't know they were going bad prior to the raised rpm unless you had a scan tool        

[Doubletrouble]

All good advise. I'll be watching this thread.

[Njbenz]

Thank you all for your advice and help. Being that the injectors are original and 23 years old, I’ve decided to order some 50HP Ducky’s and replace them. 
 

Could the VP44 still be in issue in terms of timing going bad? 

[dripley]

Yes, it could. But I would wait and see if the injectors clean up the problem. Either way you needed some new injectors. I ran my OE`s near 200k not knowing any better but did not experience what you have. I did that in about 8 years and not 23.

[IBMobile]

3 hours ago, Njbenz said:

Could the VP44 still be in issue in terms of timing going bad? 

A  P0216 VP44 Fuel Injection Pump Timing Failure code would pop up.

[Tractorman]

On 6/29/2021 at 6:18 AM, Njbenz said:

When I start and idle the truck over the past week, I can smell what seems like unburnt diesel from the exhaust pipe. After a few minutes driving down the road and at a stoplight, before the engine is it operating temperature, I can still smell the rich diesel, and inside the cab my eyes start to burn

 

If I was experiencing fumes getting into the cab to the point of making my eyes burn, I would be looking for a an exhaust leak in the engine compartment.  A cracked exhaust manifold or leaking exhaust manifold gaskets could cause this.  The air intake for the cab ventilation is in the cowling just behind the hood.  A cracked in the exhaust manifold can close up as the the engine warms.  If the crack is large enough, the turbo could be losing drive pressure, which could account for low engine power.

 

Another source for fumes inside the cab could be engine oil leaking on the exhaust manifold while shut down, then burning off for awhile after the engine is started and the truck is driven.

 

- John

[Mopar1973Man]

100k to 150k you just need the change out injector they are wasted. Even though it still starts and runs fine.