Engine "Miss" @ 2200 RPM, 3/4 Throttle??? & Help!

[Buffalo]

I have an '03, HO with a Van Aaken C-3. 2 (duration-only) box, Tone Ring Mod, AFE ProGuard-7 air intake system, & a 4" Magnaflow muffler.



On, only, the HIGH level (130 HP), the engine has a "Miss" @ 2200 RPM's & 3/4 or more throttle. This "Miss" lasts for only a fraction of a second & goes away. Does not do it on the 65 HP or stock settings. You can hear it in the exhaust note & feel it, slightly. Also, on the Dyno, @ the 65 HP setting, I made 341 HP & on the 130 HP setting, the truck only made 6 more HP (347).



In researching the problem, it seemed that this was the point which the engine was running out of fuel. So, I just installed a Glacier Diesel Power GFS-392 (Walbro) fuel system. The new pump seems to move a lot of fuel. However, I still have the "Miss"!!! The engine does seem to have a slight bit more power at the higher RPM's, though.



I've sent the VA C-3. 2 back to VA & it checked out fine. They added a few newest programming upgrades, at that time.



What are the chances that the small, stock turbo is running out of air at this point?



I'm a bit lost as to what to do next. Sure would appreciate any suggestions.



Thanks.



Joe F. (Buffalo)

 

[R_Painter]

130 hp is too much for the stock trans could it be trans slipping a little. just because you put a walbro pump on does not mean the truck is running out of fuel. the walbro keeps the cp3 injection pump happy but the pump may not be able to keep the rail up to the demand of the duration box. you could be running the rail pressure low and that is why loss of power and a miss

 

[DCreed]

on other year trucks this has been the result of loose electrical connections(grounds),the IAT, and also the MAP sensor. Let us know!

 

[Buffalo]

Thanks for the replies.



R Painter: You're theory is interesting. I never thought of my truck as being a higher HP truck. Thought my mods were pretty mild in comparison with what many others have done. In fact, at May Madness '06, which is where I ran it on the dyno, my truck was the lowest HP, 3rd Gen. on the rollers. BTW, I don't know if it matters but, I have the NV-5600, 6-sp. trans with the stock clutch. I pull a 7000 lb. travel trailer, in the mountains, & it doesn't seem to slip as far as I can tell. I'm only guessing here but, I would imagine that that would put quite a bit more stress on the clutch than the dyno run (Dynojet) that is not a "load dyno", as far as I can tell.



Is the VA (duration-only), 130 HP setting considered to be 'high fuel usage'? Enough to lower the rail pressure to the point of causing the kind of problem I'm experiencing?



Thanks.



Joe F. (Buffalo)

 

[R_Painter]

I would ask area your area to see if you can find a friend that has a module that does pressure and timing or duration. to see if the added pressure will help. if you find one and run the truck without a miss I would say rail is running dry if it still happens you may have a slight problem that is yet to be found.

 

[MMeier]

Joe, see if you can "borrow" a rail pressure gauge and see what you have. I know when I made my 551 HP run, it dipped a bit at first then recovered. If you don't mind, shoot me your number in a PM, kinda sorta drove over the cell with the '93 a few weeks back, didn't fare to well!!

 

[betterthanstock]

I have an '03, HO with a Van Aaken C-3. 2 (duration-only) box, Tone Ring Mod, AFE ProGuard-7 air intake system, & a 4" Magnaflow muffler.



On, only, the HIGH level (130 HP), the engine has a "Miss" @ 2200 RPM's & 3/4 or more throttle. This "Miss" lasts for only a fraction of a second & goes away. Does not do it on the 65 HP or stock settings. You can hear it in the exhaust note & feel it, slightly. Also, on the Dyno, @ the 65 HP setting, I made 341 HP & on the 130 HP setting, the truck only made 6 more HP (347).



In researching the problem, it seemed that this was the point which the engine was running out of fuel. So, I just installed a Glacier Diesel Power GFS-392 (Walbro) fuel system. The new pump seems to move a lot of fuel. However, I still have the "Miss"!!! The engine does seem to have a slight bit more power at the higher RPM's, though.



I've sent the VA C-3. 2 back to VA & it checked out fine. They added a few newest programming upgrades, at that time.



What are the chances that the small, stock turbo is running out of air at this point?



I'm a bit lost as to what to do next. Sure would appreciate any suggestions.



Thanks.



Joe F. (Buffalo)

One of my friends let me try one on my 03 about 3 years ago, and it did exactly the same thing, It scared me when at 70 mph I stepped on it and it felt like I had switched the ignition off for a fraction of a second. That's when I decided to go for bigger injectors. I liked the throttle pedal feel on the low setting though. Very linear.

I recall reading (probably on DTR) a thread on the VA 3. 2, and everybody said that's how it works around 21-2200.

 

[Buffalo]

Thanks for the replys.



If, infact, the VA 3. 2 is running the rail dry, what would the fix for that be? A high performance CP3?



I wonder if replacing the VA 3. 2 with something like a Smarty might be a more economical & better choice?



Since I'm now pumping more fuel to the CP3 with the GFS-392 (Walbro), is the CP3 running dry or just the rail? When the miss is occurring, am I risking any damage to fueling system parts from running the rail low on fuel & lubrication?



RPainter: In your last reply, you suggested running a "pressure module", stacking it with the VA3. 2, I presume? Do you feel that the "extra" pressure will provide 'more fuel' to the rail & overcome the negative effects of the VA3. 2?



Betterthanstock: Thanks for the 'heads-up' on the VA3. 2 thread on DTR. I'll try to find it.



Thanks, everyone, for your help.



Joe F. (Buffalo)

 

[R_Painter]

If you put a pressure box on it will fool the ecm to think the rail pressure is low on pressure and the ecm will tell the fca to increase flow increasing pressure hopefully raising rail pressure. on my set up with my triple dog racing program without my quad box I get a high rail pressure code with the quad box o I dont throw the code due to the pressure fooling.