First time posting on this site, i have to say this site is amazing always have found stuff that has helped me. Well im hoping someone could explain whats houng on with my truck. First and foremost the truck is a 1999 2wd 5 speed 3500 2nd gen cummins and it has a cold air intake and a intake horn, edge ez, 50hp injectors, new H. O vp44. The truck has 307k miles and runs amazing and has no issues. But when im driving on the highway at a steady speed around 80mph the sound in the engine bay will change every 15-20 seconds it is most deffinetly the sound of combustion changing and or the injection timing changing. The truck will have the typical knocky 24v clatter that sounds kind of like a machine gun but every 15-20 seconds that knocky sound will totally disappear and the engine sounds so smooth at this point, after about 5 second, sometimes a little longer it goes back to the klattery machine gun sound for another 15-20 seconds and then back to the smooth sound. It is most deffinetly the sound of combustion and not like valves or anything like that im 100% sure of that. Its like the ignition timing is changing and changes the engine sound. Exhaust note doesnt change its all under hood noise . Has anyone ever seen this or have a clue at how and why it does this? I wish i had a way to view the timing commands in real time and see if their is a correlation in timing changing and the sound changing. It would be nice to find a way to make it have that smooth quiet tone all the time while on the high way it would deffinetly keep some decibels off  

Jesus im gone for a few hours and the whole thread blows up, but to awnser on my injector life i dont think they have that many miles on them, the truck fires so fast hot or cold, even when my grid heater was not working(which i fixed) at like 10 degrees out the thing barely cranked at all fires immediately then sounded like a bag of bolts cus the lack of a grid heater. And ive always kept good filters and ran good injector cleaners either hotshots or motul. And to awnser on the scanner question it says calculated load value and on every vehical ive ever used it on even a 2011 cummins with brand new industrial injection injectors it would say 0% at idle i dont think its very accurate on the true load value being at idle and not moving the shitty scanner probabily thinks theres no load cus its not moving, i could have a family friend of mine plug it in with their snap on or autel scanner. And how come 815 rpm is high?  And how are quadzillas injectors i saw a set of 75hp injectors from them for like 7 or 800 bucks, i was surprised at how cheap they were are 24v injectors alot cheaper than 6.7 injectors, the set we got for the 2011 work truck were like over 3grand

38 minutes ago, daav544 said:

are 24v injectors alot cheaper than 6.7

 

Common rail fuel injection started in 2003 for Dodge Cummins engines.  Each injector has an electrical coil and is fired electronically.  Every injector has fuel pressure available 100% of the time via a common fuel rail.  This is why these injectors are very expensive.

 

One new OEM Bosch common rail injector costs almost as much as 6 new OEM VP44 era injectors. 

 

- John

Mechanical injectors require pressure to open the pintle to fire. As the injector wears the pop pressure falls and timing advances. This is the down fall to 24V injector systems. To keep timing correct you need to at least have them tested to see if they qualify. Yes I know 24V injectors could be completely wore out and still run and drive. Again the only way to verify is to remove all 6 and pop test. But keep in mind efficiency will degrade and possible to blow a head gasket from the advancement of the worn injectors because your mechanical advanced timing with boost and bye bye head gasket. Because as pop pressure falks its opening early. So for longevity I highly suggest pop testing injectors. I've seen 40k injectors sink to 280 bar because of shim failure.

 

 

293 bar = 4,250 PSI lower limit

327 bar = 4,750 PSI upper limit

310 bar = 4,500 PSI set pop pressure.

Edited March 30, 20241 yr by Mopar1973Man

Would it be possible for me to do a pop pressure test with one of those table top diesel injector testers that are a couple hundred bucks? And can these be rebuilt and i throw a set of 100hp nozzels on them, im pretty mechanically inclined i rebuild that 6.7 soip to nuts myself at the last company i worked for when it needed injectors and dropped an injector tip cus my boss wouldnt listen to me when i said it needed them, also rebuilt an allison 1000 myself. If its possible on one of those table top machines id like to go that route and get it done in a day as this trucks my daily and i couldn't have it down for more than a day or 2 borrowing my g mas car or something

Sure. Just do me a favor? Please post up what you got and how you did the pop test. The article database would love to have a new one for pop testing. 

So one of those little diesel injector testors would suffice for doing the pop pressure test like the one pictured? And i most certainly will make a little write up on it. Would just be easier for me to do it and be able to have my truck back and running that day,  plus you know the saying if you want it done right you gota do it yourself sometimes lol

Tester should work but you are going to need the collar fitting for coupling you injector to the test stand.

Yea i seen those collar fittings. To be honest though i might just pull the trigger on some 150hp injectors, the dude that sold me the adrenaline has some used DAP injectors with only 4000 miles on them, hes going larger cus hes got compounds and has a set of 200hp ones waiting to go in. I can probabily get them for like 250 bucks and with the adrenaline you can set the percentage of injector you want to be used (idk the actual terminology for that setting on the tuner) but i saw you van dial back larget injectors incase you have a stock turbo and dont wana just smoke out each intersection

$250 is a good deal.  New coppers and orings are about $20.   Start the fueling at about 85% then 100% at 5psi, 125% at 10PSI and 150% at 13PSI and you will have a pretty clean tune to start that keeps moving.  Then adjust to your preferred fueling curve.

@dieselautopower where is your Quadzilla crew?

Yea i thought 250 was a great deal especially with only like 5-6k miles on them. Cant wait to feel this thing really make some power, whats you guys out look on head bolts or studs for the power level ill be at(stock turbo mind you) i saw a video power driven diesel made about these affordable head bolts i forget the brand but they seemed like a good option for my rig . And whats your opinion on doing them one at a time and what would be the best way to do them one at a time like follow the regular head boly torque sequence and just change one stud at a time? 

Edited April 3, 2024Apr 3 by daav544

@Mopar1973Man so i hooked up the adrenaline, everything aside from fuel pressure, Oil pressure, and the pump tap, i put the truck on the default v2 tunes on level 3 (can bus only) and the truck ran like a dog didnt feel like it was building any boost so i disconnected it cus i didnt want to harm anything. Now the truck every so often feels like it wont make any boost then all of a sudden kicks in and will take off like normal. Im assuming this is a map sensor issue or map plug issue, any ideas? 

@Mopar1973Man pretty sure i found my map sensor issue if you look close one of the pin tabs broke off my truck connector plus its filthy

So you need to go to NAPA and get a pigtail for the that MAP sensor. Dielectric grease is known for collecting grit too.

Yea i ordered a plug from orileys it will be here tomorrow, lucky i got a good eye for **** like that or id have thrown a map sensor in it and been pulling my hair out

@Mopar1973Man you think thats deffinetly the issue? Thats the 5v supply pin so id deffinetly assume it would frick things up. My scan tool would only read 29 in/hg which is 14psi it wouldnt move from that reading. I belive it reads 14psi being thats atmospheric pressure so really would be zero

Would of seen it in the boost value on the Quadzilla. Possibly a code could be present.

I stuffed a tiny bit of wire into the pin just to  see if it would make a difference and ease my mind that its just the plug and thats all it was, ill deffinetly have to  keep an eye out on future plugs for that. Easy to miss and start chasing ghosts

@Mopar1973Man adrenalines hooked up and working great, dont have the pump tapped yet. But any way i did a front main seal today and the mfer is leaking i should have gotten one with a wear sleeve but any way i had seen a video on installing a front main and the guy said to hit the seal in a little deeper to get it out of the groove , have you heard of this? Should i try that first before ripping everything back apart

And or do you think id be able to slip a sleeve in the existing seal? Im hoping i could do that i really do not wana do this all over again

Oh and i forgot to tell @Doubletrouble with the adrenaline hooked up the engine load at idle is right at 5% 

2 hours ago, daav544 said:

But any way i did a front main seal today and the mfer is leaking

 

Just double checking here.  Was the new seal a PTFE seal?   Was it installed dry (as it should be)?

 

Interesting coincidence - I just installed one yesterday.

 

- John