I installed some Mach 6 injectors in my truck a couple of weekends ago and the injectors are awesome, very please with them, lots of power and nice smooth idle. When i step on the gas with the injectors only, NO comp box on the trucks performs awesome, no hesitations and just full out power. Now when i do the same sort of run with the comp Box on, no matter what level i use the truck seems to stutter like it is running out of fuel, or it is defueling. Anyone had any experiences like this? The Comp box is the Drag version. Could the comp box be bad? It only did it once in a while when i had the old injectors in, and it was not so apparent either. Thanks for your time and help.

 

Does it do the same thing if you "roll" into the throttle ,rather than
"mash" the pedal ?

 

Something ain't right. With your combo you should have absolutely ZERO defueling. What are the sub levels of the comp set on? Reason I ask is cause I run around with my comp on 1x1 and with the smarty turned on (which eliminates low and high end defueling) I can still get the studder and jerk of defueling. Turn the comp on 5x5 and holy dear mother of christ. The truck pulls like a freaking train.

 

i agree you shouldnt have ANY defueling. me and you have close to the same setup but your injectors are a little bigger but still pretty close. i have to say my truck runs very very well with just the injetors but when the box it on, holy shmoly, it freakin feels like a dragster lol. smoke barely if any clears up. you should absolutely move with mach 6s and a drag box.

 

Now that 480/880 run- that was with the sp66 and your old jammer (?) injectors? With the mach 6's might be close to that with the comp off- if I recall correctly Doug said he was in the 490's with the M 6's and the steriod b-1 with the comp off.

Ok the following is a personal theory and I am probably wrong, but here it goes: The drag comp compensates for the 2700 rpm defuel by adding more fuel than the ecm is taking away. Now you've removed the ecm defueling with the smarty so once you pass 2700 rpms the comp is going to be adding crazy fuel to compensate for non existant defueling and the result is,...... studder?

I'm not sure if this is the source of your problem, but I thought I'd throw this out there and maybe someone will talk some sense into me

 

sounds like a good therory but i have talked to a few people that are running comp or drag versions and have the smarty and have no shudder. i had the pleasure to try out the smarty since Bob Wagner sent me the beta box and with my DRAG version comp and my injetors and the smarty, i never ever had any defueling, only way to much fuel for my little ATS 2000 turbo, either need twins or a BIG single for the fuel that i have. either way, you shouldnt be experiencing any defueling, i would call edge and have them check your box. dosent sound right to me.

 

Yep I get absolutely no shudder.Ive got stock injectors and turbo but run the marty on 8 and the comp on either off or 5x5.I mash the pedal as well and no studder at all.Sounds like his ip is ready to bite the dust

 

I see you are located in Maine... Does this mainly happen when the outside temp is below 40 degrees? This seems to be a common problem with the Comp box, and it shows up more with larger injectors. I've heard all kinds of theories why it happens, but I'm not sure anyone knows for sure. I do know that on a pickup that had the problem, and they changed to a TST it went away. Can't tell you if it would happen in all cases.

Paul

 

Thanks for all of your replies, just got the internet back up and running, thats why i have been absent. I was out driving the truck last night and it seems that if i roll into it nice and easy all the way to the floor, it does not seem to hesitate as bad as if i were to just flat foot it from a roll. The tempature up here in Maine has been nice, mid 70s or so, so i dont think that the tempature is the culprit. I had the Inj pump replace last summer, but that does not mean anything with those peice of junks. Thanks again for the ideas.

 

I just got off the phone with Edge products and i described to him what was going on and he said to make sure my ground was good and to make sure that my connection to the pump was good because he said that a bad connection in either one of those spots would cause the truck to do what it is doing. He said that if that did not fix the problem, he would warrenty it out and give me a new one.

 

Mike, you still running stock fuel lines on your truck? I wonder if the VP is running out of fuel?
I'm just thinking outloud.

 

hey DOUG, i was readin your sig and i have seen the MYSTERY SWITCH in some sigs quite a few times. would you please tell me what this is. i no they have a valet switch for the 12vers but i have never heard of such a thing on a 24v?

 

never mind i found out what it is, all i had to do was look a little . wow looks like a pretty neat deal. did it make a big difference in your 0 to 60 time at all? i am defiently going to put one in now.

 

Yeah, the fuel lines are stock and i look at my fuel pressure gauge and it never goes down below 15psi. I just checked my connections and made sure that they were good and then i took my truck for a ride. After she was good and warmed up i did a handful of test runs, first on level 1x5 then 2x5 and then 3x5 and so on up to 5x5. The only time that it did what i explained in my first post was on level 1x5. On each of the other runs it ran flawlessly with unreal power on 5x5, almost scary fast. ON level 5x5 i flatfooted it from a dead stop and brought it all the way to 90mph and there was no hesitations or anything of the sort, so now i am confused, maybe my injection pump is weak, it would not surprise me if for some reason it was. Anymore thoughts would be great, thanks again

 

Well, it looks like you have a SO truck so running out of fuel should be less of an issue with a good VP, but still sounds like a bad VP or fuel supply issue by my thinking.....not that I'm the most experienced on this board, but makes sense to me. I just bought a set of M6's myself and I actually expect some issue since I have an HO truck, although I haven't gotten them installed yet. I expect to have to order a Hot Rod VP shortly after although I honestly hope I don't have to for a while. Were you M6's new or used? If used, you could always send back to Don and have them pop tested. Mine were used so I sent them back just in case although it was probably a waste of freight money since they were just 2 months old to start with. I'll keep you posted if I have an issue after I get them installed if I can help. Hopefully you'll get it figured out sooner that that though.

Good luck, Matt