Predator problem?

[nbloecher@yahoo.com]

I bought a VIN locked predator off ebay and had it reflashed,i programed the truck and the thing ran really well,on all levels.Since then it hasnt run 50% of what it did,i just replaced the fuel filter that didnt do a thing.When its running well itll blow smoke when its not it doesnt smoke,without changing the program.When i first got it i had a buddy twist my arm to put on the 120 level,i did for a couple of country road runs,the thing was scary fast,for a truck.It would break the tires loose till about 35mph,and blow loads of smoke.I wasnt hard on it,no boosted hole shots and no 4-5th gear.Im wondering is it possible there is something wrong w/the programer,does my ECM need to be reflashed?I had the injectors replaced about 7k ago.Im running stock exhaust&brute force intake.Ive noticed these diesels seem to be even more finiky w/atmospheric conditions,as opposed to gassers,the thing wants to scream when its humid and cool.You guys have saved my hide before,on the injectors,anymore help would be greatly appreciated.I just realized i put this thread in the wrong section,i apologize.

[killerbee]

1. scan for codes
2. did you do any other modifications at the same time (what intake are you running, etc)

[nbloecher@yahoo.com]

Thanks for the reply Killer.I have the stock exhaust,brute force intake.When its not running right i usually reload a different program,i did this the other day,and it started shifting pretty hard,harder than ever before.It also sometimes changes the rythm of the door adjar bell,thats what makes me think its the programer.There is a guy on diesel place that has a similar problem,says he doesnt think hes getting half of the advertised power,he got his ECM reflashed and said it made a difference.Ive also seen a couple of guys on the diablo website forum that have basically the same problem and the guys from diablo said this is the first time they have heard of this.Im running on the 120 right now and compared to the first time it feels like its running at about 60%,Ive heard that you need a lift pump for that kind of hp increase,but why would it run so well the first tune,and not so well after?Thanks for any help.

[nbloecher@yahoo.com]

Just did some more reading on the diesel place.Does anybody believe this could be a fuel pump or relay issue?From what ive seen the 120 tune should be blowing loads of dark smoke,im blowing smoke but the opacity is not there.A guy on there says on 65 tune hell break his tires loose from 8mph into second gear,i cant even do that on the 120 tune,granted im running 265 goodyear mtr's and their soft as hell.

[killerbee]

It could be anything, but i'd start with your intake. Is it an oiled element? if so, it is time to get rid of it, and clean your MAF sensor.

And again, scan for codes. That is the first thing you have to do.

Once you have a tune downloaded, it will always behave the same way. The tune is not the issue, though something else (physical, not digital) can kill power.

[nbloecher@yahoo.com]

Thanks again Killer,ive scanned and its not showing any codes.The brute force intake is a dry filter.I dont know diesels all that well but,even before i got the programer,this truck would run different in different conditions(hot vs cold and humid vs dry)some days the truck would run very well,others its just not as snappy,i dont know if thats normal(im talking a minimum of 20-30hp difference)I was hoping that,that would go away w/the new injectors.If this isnt normal im probably going to try dumping this truck.You would think 420hp and over 700tq would be able to break the tires loose.In short i guess i never should have tried the 120 program,for now,im hooked.

[killerbee]

I do notice that when my IAT climbs, due to design limitations, that the truck will be a slug, until it comes down. I have noticed it can really make a SOTP difference in response also, turbo lag seems to increase with the heat.

If you have the pred, you can monitor IAT. I have seen it climb to over 200 where I live. It is a real difference from 100 F, the compressor is not real happy at higher temps from my experience. Perhaps that is what you are noticing, extreme turbo lag that doesn't really kick in the power until you are down the road a piece.

[nbloecher@yahoo.com]

While its hot around here (101-40%humidity)your right it doesnt like hot temeratures,it ran alot better once it cooled down last night.After driving last night i noticed when ive turned the ingnition on last night getting ready to start it,it didnt do anything,like it was in gear.Thats about the fifth time its done that the last few days(turn the key to start and nothing happens i turned the key back to the neutral position and try again,that usually works)thats what is making me think its something w/the ECM,that and the erratic shifting(sometimes hard sometimes normal)Again thanks for your help Killer.