100hp 7x.009 injectors EXHAUST POP?

[Waydin_Stewart]

Hello, I would like to apologize for the long post!

Okay so I'll start it off with what I have done to the truck so far. It is a 1998.5 2500 5-Speed 4x4 Cummins. A little under 900 maybe 1000 miles ago I have installed a new VP44, Airdog 100, OEM Cummins connector tubes, 7x.009 100hp injectors, and I also had to have my computer rebuilt because the throttle circuit was shorted out(I may also add that the truck used to prime for 3 seconds and it no longer does, I used to be able to access system function from a scanner and no longer can, The truck sounded ever so slightly different after I installed rebuilt ecm aswell). I have a few more things coming within the next 3 days including banjo washers for the bolt at the back of the head(I may also buy the Fuel Grommets at the return T soon aswell), BD Boost Fooler, and an Adjustable Turbo Elbow. There is also a programmer for sale that I may pick up aswell next week. But anyways now to my problem. I installed the new injection pump and airdog at the same time and then drove the truck for about 2 weeks and it sounded slightly different but ran fine.Then I decided to pull the trigger on some DFI 7x.009s . I installed them and the truck started up, smoke white for about 30-45 seconds and slowly went away and the "Air-Filled" idle started to go away too. The truck still had a rough idle after letting it sit for a while. So I got into contact with Chris and he sent another set out the next day. Boom the rough idle is gone. If I am in neutral and let the RPMs climb and then hold them at a certain spot the truck will shake quite a bit or whenever I accelerate hard the truck shakes quite a bit aswell. But the acceleration could be bad u-joint on front driveshaft maybe? If I give the truck more throttle there is an odd "miss" sound coming from the exhaust(not from the motor that I can hear anyways) The sound reminds me of an old non turbo 7.3. I ordered feeler guages and they will be here Monday and I will be adjusting my valves to see if that helps as they have never been adjust before. I know of two 2002 6-speed dodges that have 100hp and 150hp injectors and they do not sound like mine. Does anyone have an answer of how to fix it? I'm guessing maybe the tune in the computer is off and I just couldn't hear it with the smaller stock injectors or maybe the valves are opening slightly off and it is doing this or something? 

[Cronus577]

I wouldn't be surprised if it has something to do with the ECM. It's been stated over and over that rebuilt units are more problems than solutions and a lot of people end up just buying new ones since some features don't work for some reason after getting it flashed. Does it sound anything like mine? Ended up being a bad injector that I had put in less than 2 months prior to it failing. Do you have a way to monitor the fuel pressure? Are you sure the key way for the VP44 was aligned correctly during the install? And in neutral the truck shouldn't shake at all since there is no connection to the driveline. A few other things to check for is all of your grounds and your alternator to see if it's putting out too much AC noise. 

Edited March 18, 2017 by Cronus577

[Waydin_Stewart]

I have no way to monitor fuel pressure.I would only assume it would be at the preset psi and isn't dropping below 10? I have wire wheeled the grounds on the engine, frame, and quarter panel. I have used electronics part cleaner on almost every connection on the truck at this point. It is a "newer" alternator so I wouldn't think it would put out that much AC noise. When I installed the first set of 7x.009 injectors it sounded like yours but now it doesn't. So is it normal for the truck to shake more with bigger injectors in neutral if I hold it at a certain RPM? If not then I know there is an underlying problem with tuning or install. I read multiple write ups before doing the injectors and this is the 4th time I have messed with injectors in this truck. First 2 times everything was fine afterwards. I have checked the key way 6 times to ensure it is in. Which it is, you can see the key clear as day in the gear slot. If it was the tune in the computer would I be able to put a different tine on it and see if it changed it? I know that smarty can build you a tune file to flash your ecm with. But then I have the problem of not having a smarty.

[Cronus577]

The first thing you should do before getting any kind of programmer is to get the basic gauges for the truck, Fuel Pressure, EGT, as a must and trans temp for auto, otherwise a boost gauge or whatever you want. Bigger injectors shouldn't make the truck shake any more than normal, in fact, I heard that with the bigger nozzles, the VP44 doesn't have to work as hard to deliver the fuel. As far as the AC noise, it really doesn't matter how old it is, it can still be an issue even with a brand new one, always good to check.

 

When you replaced the VP44, did you make sure to get the stock SO version? And did your replacement ECM get flashed with a 235hp tune or a 245hp tune? I've read some articles that a SO truck doesn't like the 245hp tune

[Waydin_Stewart]

I told the company that rebuilt the internals of my computer everything about the truck. All the way down to the vin number and 5 speed and 4x4 and SO 235hp and mileage. It is a SO pump and I actually hooked a 245hp computer up to the truck to test to see if my computer was bad and the truck ran weird. It idle rough as heck at first and then smoothed out and it honestly seemed quieter. It seemed to idle faster if that makes sense haha

[Cronus577]

I would take it to a nearby Oriley's or Auto zone and check it for any codes. Even though it may not show a CEL it may have some stored. 

[Waydin_Stewart]

I have my own code reader/Scanner that will read and erase codes, monitor live data and everything. The college I went to has a scanner that used to be able to access the system functions until i had to get a new computer for it. It does have a APPS/TPS sensor voltage too low but O'reileys says I'm not allowed to get another one until I prove mine is messed up...I have had 3 bad ones from there in 2 years and then when my computer went out I started with the APPS/TPS to see if that would fix it but I don guess that was bad. . But its a lifetime warranty haha. The one I have now has the adjustable throttle screw rounded over on both sides of adjustment and its got like loctite Red on it? So that sucker ain't moving anywhere.

Edited March 18, 2017 by Waydin_Stewart
Add-on

[dripley]

I think you are going  to need to try and solve you problems before adding any more performance upgrades. Is the ECM you had rebuilt still under warranty? If so i would contact them and try to get another. If you cant communicate with it on your scanner that worked before that is not a good sign. As far as rebuilt vs new, new ones have not been available for a quite a while. 

 Alternators can and are bad out of the box. It needs to be checked.

 Gauges are your friends. Never assume your fuel pressure is good because your system is new. A FP gauge will alert you to any problem that might arise when it arises and not after you fry a VP.  With the bigger injetors and EGT gauge becomes necessary, more fuel, more heat especially with adding a tuners.  Now you have more fuel, and more HP so you need more air so boost gauge is in order to monitor that. Most tuners do boost fooling which allow you put more air in the motor.

 You describe a vibration while free revving the engine and it continues also under load, did this start with the new injectors or the new ECM? How is your harmonic balancer? It would vibrate under both conditions. If it was the drive line it would not vibrate while free revving the engine. Never hurts to get under there a check it out.

[Waydin_Stewart]

I will be getting a gauges soon as well. The vibration started after new injectors were installed. I'm not going for high hp and black smoke I'm going for good MPG, reliability with and without a trailer. Maybe in the furture Ill get compounds and studs and a pump tap programmer but for now I'm just looking for an a-b truck. Not an A-and lets see if we can get it to b super fast.I don't dog this truck. Since the new injectors I've gave it full throttle maybe 5 times? just to see if what I "did" to the injectors helped haha.

[dripley]

i definitely like the power I have but am not interested in smoke. Mine has been pretty much smoke free until here recently with the addition of some new injectors. I need to some give love to my intake system and fix and find some boost leaks. Just not into the smoke.

[Mopar1973Man]

Time to pressure test the system. 

[dripley]

yep.

To the OP. Even if you just want a B grade you need to figure out this vibration and you have already added 100 hp injectors. If you still have the old ones pop them back in and see if it goes away. Sounds like swapping out the first ones for new ones helped. 

[Waydin_Stewart]

I don't have the originals anymore. I sent them back as a core already. I need to figure out the exhaust pop and vibration.The vibration could either be a cylinder not firing which would also cause the exhaust noise im guessing. OR the shake in neutral is just what comes with bigger injectors but the shake going don the road could be u joints or unbalanced tires?

[dripley]

You should not be shaking just because of the bigger injectors. Unless there is a problem with one them. I am thinking since it vibrates free revving and under load that it probably is not a drive shaft. But it is easy to check out the drive shafts. 

[Waydin_Stewart]

Okay I think I understand what to do! Light a match and burn it! I don't have unlimited funds so my options are limited haha. My local diesel shop charges $300 initial plus $300 an hour. I'm stumped as to what it could be. Chris sent me the first set and it had a rough idle. So he sent another set out.The rough idle went away. I cant afford to send the truck to the shop so I kinda have to figure it out at this point as its my only vehicle.

[dripley]

I cant help but think it is fuel related since the vibration started with a new set of injectors. Do you have any evidence of fuel leaking anywhere? Double check anything you messed with from the VP all the way back thru the new lift pump to fuel tank. Check the high pressure lines also at the vp and the head.

 I read your post again. You changed a lot items. Did you do it all yourself or have that local diesel shop do it? At $300 to show up and $300 an hour they ought to be miracle workers. A dealer is not that expensive. It is possible something else than injectors is causing this but it seems all was well until you added the bigger injectors. 

 The ECM could be part of the problem but I am no expert on how the VP and the ECM interact with each other. It is suspect however since you have no short prime at key on. If you bump the starter with no engine start does the lift pump run for 25 or so seconds? Does your WTS light illuminate right away or is it delayed? Can the truck be started right after inserting the keys? These are all signs of ECM problems. If yours is still under warranty you probably ought to talk with them.

 

All that being said, if this did not start until the injector install, it makes that part of the work done the prime suspect.

[Mopar1973Man]

Did you tighten the injector hold down first or the cross over tube first? If you did the hold down first then it could produce a high pressure leak between the injector to cross over tube and leak into the return rail which you'll never see.

[Waydin_Stewart]

My computer has I believe a 1 year warranty on it. The alternator has been changed so if it is causing problems I can get another one on warranty. I tightened down the hold downs first as every video I watched they did/said that. I guess I could undo the hold downs and then the injection lines and then tighten the injection lines first. Would I have to remove the whole injection line to do that or just loosen them? On a side not I'm having hard start issued but that is because its sucking air at fuel return T. I park truck uphill and it takes a while to start. Park it downhill fires right up. It has new banjo washers on the back of the head as I just installed them yesterday for the hard starts to find it was the return T leaking instead. I know its not running right. Its obvious its not by the exhaust pop and shaking. IF I romp it in neutral The truck shakes and the exhaust pops so it is injector relation or atleast injector timing related. Ill also be adjusting the valves as soon as my feeler gauges come in to quite the motor and gains my minuscule mpg back. I posted a similar thread on another forum and got minimal help. You guys are very helpful! I have a video of the truck driving and you can hear the exhaust pop if you would like to listen.

Edited March 20, 2017 by Waydin_Stewart
Add-on

[Mopar1973Man]

What you want is the injector lose so it floats in its hole so when you tighten the crossover tube lightly the crossover tube can self-center the injector to the crossover tube. Basically, you need to almost do the install all over again and tighten the crossover tubes first not super tight but enough to ensure the tube is firmly seated before clamping the injector preventing from rotating.

[Waydin_Stewart]

Well its not hard to redo the install. Ill do it tomorrow when I get time. I have the dang tools memorized to do it haha. What your saying make sense as to how it would align itself. Would you like to hear the video if I can attach it and it work right?