I have posted this before, haven't really been able to resolve and now it appears to be getting worse unfortunately.


I have a VA150 box on a '02 w/ ZF tranny. I have had trouble ever since I have had it with what I thought was the electrical connections on top of the engine where the VA plugs into the engine's electrical system. I am now not so sure this is the problem. I have been through the route of ensuring all the pins are straight, have used dielectric grease etc etc, but still have the problem.


The problem is that ever so often, seems to be occuring more often now (every couple of days or so), I get what I have heard described as "bursting" but only between idle and about 1/2 way down on the pedal. What happens is, I am stopped idling, ready to pull out onto a road/highway from a parking lot, and when I give it the throttle, I get a huge hesitation, like no fuel basically, it'll die completely if I let it.


I have back off the clutch, give it nearly full throttle and slip the clutch in order for it to stay running to get out of the way of oncoming traffic. Then I have to drive it like a hot rod to keep it alive. And the whole time it sounds like an old diesel, no pilot injection at all at any RPM except idle and black smoke, more than normal I would say. It'll idle just fine, just as quiet as normal like there is nothing wrong. But as soon as you touch the pedal, it'll die unless you give it nearly full throttle, then the bursty sound of it coming back to life w/o pilot injection.


I can wiggle the wiring harnesses till he11 freezes over and it does nothing. I can disconnect all 4 connectors, reconnect, still have the problem. If I disconnect, go back to stock, all is well. Then reconnect the box, all is still well. What gives?


A new piece of information I have learned since the last 2 times it has done this is that when I first start the truck (before it does this), it'll start up and immediately shut right back off. Then I restart (no long start or anything, it fires right back up), then I have this problem. If I don't get the immediate quit when starting, I don't seem to have the problem. They seem to be related I think. It does this with a hot and cold engine.


I vaguely remember having the immediate shutting off problem at stock when I first bought the truck once in a while, dealer said it was nothing and don't worry about it, but never had the problem with it hesitating and sounding like an old diesel w/o pilot injection and being a sitting duck in traffic. This has become a safety problem I'm afraid.


I have thought this problem was due to the connectors not seating good, but am starting to think it is something else now.


Btw, I have good clean (recently replaced) filters, good fuel, and no codes thrown (yet). 52K miles on the engine.


One other thing I have noticed recently, not sure if it's related or not, is driving down the highway say at 70 or so, and it feels like it might be oscillating a little with the throttle, like it's not as smooth running as it ought to be, but it doesn't do it all the time and I can barely notice it. At first I thought I was imagining things, but I think it's there. My wife thinks I am imagining things.


If anyone has any ideas or has been through something similar, any help would be appreciated. I think I will remove the VA box and drive it stock for awhile just to see if anything funky happens at stock, but I am guessing it won't. Not sure what else to try and/or look at other than point at the VA box since I never had the hesitation and pilot injection disabled before the box and I ran a Quad135 before that never had this problem.


Am starting to think I should have went w/ the Edge. :-( I have been through 2 boxes now, not going for a 3rd... This is it.


Thanks,
Tim

I'll see what I can dig up from VA. I recall a couple of complaints about the ZF being hard to drive in a parking lot/traffic due to surges/jerkiness.





It wouldn't hurt to return it to stock and have the dealer check for any programming updates, especially since you possibly recall having the problem early on.

Thanks John. I guess it wouldn't hurt to take it in to see if they can find anything etc, although I doubt they will.


Btw, the jerkiness/surges is not just in the parking lot, it's there right off idle on the pedal all the time. There is idle, then a big gap of nothing, then no-pilot near full throttle on the pedal, and that's it. It's nearly like a big on/off switch on the floor rather than a throttle.


Thanks,


Tim

Big programs freak out the cruise controll. Gives it a surge type feeling. Duno if this is maybe causing your surge at 70 mph?


Other wise hope you get it figured out.

Nope, I never use cruise control, not even on long distance trips. I like having control over the throttle. I doubt the cruise on my truck has ever been used to tell you the truth.


Tim

goes to show you different strokes, I cant stand not having cruise


I get a slight "surge" sometimes with the TTS cranked up since it has a real touchy pedal.....allthough this dont sound like your problem.


How long have you ran around lately with it VAless to see how it acts?

I have had similar problems with my truck before, it feels to me like the pedal has a dead spot in it. It does it when I come up to a stop and then take off, I can push on it and nothing happens and then the farther down I go it will take off all at once. It doesnt do it all the time, and wont do it if I take off really easy and feather it. I have a VA box also, but it does it when stock or with any of my boxes on. I feel it has something to do with the pedal/wiring or sensors.

Sounds about the same but I also lose pilot injection cause it's extremely noisy and also doesn't seem to have the power it normally would have at near full throttle and a little more smoke. There is a huge gap of nothing between idle and nearly full throttle. I pretty have to run it with the hammer down all the way and slipping the clutch to start as well as going from 2nd to 3rd to keep it running when it does this.


Today when it did it, I drove it back to work from lunch, it did it all the way back. I parked it and when I went home about 5 hrs later, it was fine, I didn't disconnect/reconnect anything (this time).


I haven't had this problem w/o the VA box (that I know of), but time will tell if it shows up or not w/o the box.


Thanks,


Tim

Try switching the box off and leaving installed.





One thing to remember is that a box can amplify a pre-existing condition, making it more noticeable. We'll see where this goes, then we'll consider experimenting with different hardware/programs etc.

John,


We're thinking alike, I did just that yesterday when I got home from work. I never had the switch installed, I just ran the 150 setting. Now I have the switch, albeit under the hood, but it is there now. So the next time it happens, I will turn the box off with the switch and see what happens.


I appreciate your help, and look forward to resolving this issue. I really like the box, it is exactly what the dr ordered, it has plenty of power, and is very smooth with the ZF/6 if only I could figure this problem out.


I have not yet taken it to the dealer, am a little scared to actually since I have an aftermarket exhaust, cheesebox air intake, gauges, Nicktane CAT pre-filter setup, and 265 tires. I could just see them pulling the ole GM void-o-warranty on me. I would like to keep the 200K fuel injector warranty if you know what I mean. But I may have to bite the bullet and take it in just to see if they can find anything. Although like I mentioned before, I took it in right after I bought it for the immediate shutoff upon starting issue which happened once in a while. They never saw a code, and of course it wouldn't happen for them. I still have no codes set btw.


I think I'll wait and see what happens with switching the box off next time it happens, then assuming that doesn't fix it, I'll run stock for a while to see if anything wierd happens there. A few weeks oughta tell the story if it is anything stock related or not.


Thanks,
Tim