need advice for 402 drivability
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TECH Apprentice
Joined: Aug 2009
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From: NB Canada
need advice for 402 drivability has anybody ever come acrosse a combination of parts that could not be tuned, i have bucking or surging at aprox. 2300 rpm and below depending on tune it is worst or less, it's been 7 times at tuner, 3 of them times were 3 full(10 hours) days of tuning , last time he did a enhanced speed density tune, it's even worst got a maf code on way home( i taught sd tune got ride of maf)?? my tuner is 3.5 hours each way away from me, starting to lose patients and money and time. no other tuner in erea, something like 1400km to the next one, and then i start over again, here is my combination 402 ls2, patriot stage 3 72cc,10.6cr, ls6 intake, pacesettre long tube and caths, ported tb , truck maf,cam is 236-242 and close to 650 lift with my crane adj. 1.85 rockers, 42lb inj., new o2s, any help would be verry apreciated, and making 457hp and 442 tq by the way.
Kinda hard to help you unless you have your own tuning software... Anything we tell you that might help, you can't change... and you can't post or send a tune file so anyone can help you out. If you are that far away from anyone to help you, you may want to think about purchasing your own software and learn...
Thread Starter
TECH Apprentice
Joined: Aug 2009
Posts: 389
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From: NB Canada
it is more of a question if anybody came acrosse a combination that was not tuneable for driveability( heads-cam- intake-inj.) tuner says fuel trim, timming etc is all were it needs to be, he has even went in all directions+- makes no change or verry little, just creats more issus like sarting, idling... other codes...
There is nothing about your combination that is "untunable"... I've never seen a combination that is "untunable". Now, if you have some other mechanical or sensor problem, it may be effecting the ability to tune the car - but a good tuner would see that and advise you what needs fixed...
Thread Starter
TECH Apprentice
Joined: Aug 2009
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From: NB Canada
what equipment would i need to do it my self and aprox prices, and brand, where to buy, i do understand data and have acesse to 2 otc scanners and snap-on scope, lab-top, no dyno but don't think it is necessary, if i do decide to go that route i would take all winter to study and understand, it will also help me at work to better myself in diognostics ,
BLACK02WS6 nailed it perfectly. Buy the software and learn to tune (scan tools are included). Even though it's a steep learning curve, it's well worth it especially with a set up like yours. I also use EFIlive and really like it.
I prefer EFILive myself. I would recommend EFILive and an Innovate LM-2 wideband along with a serial cable to hook the two together. I got my complete setup from Powrmax.com - good price and free shipping, but I'm sure there are others out there that sell packages as well...
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Thread Starter
TECH Apprentice
Joined: Aug 2009
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From: NB Canada
just came back for the 8th time from tunner(last one) i think i'm back to day one with tune
,he has taken out the speed density tune, he said that he has informed with experts and with that cam i am going to have to live with the surging-bucking. i am going to have to find a tuner in the montreal or toronto area(probrobly at champion motors ) were i bought most of my parts, i think its like 1600km one way trip
,he has taken out the speed density tune, he said that he has informed with experts and with that cam i am going to have to live with the surging-bucking. i am going to have to find a tuner in the montreal or toronto area(probrobly at champion motors ) were i bought most of my parts, i think its like 1600km one way trip LS1 Tech Stories
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If you buy your own tuning software, there are several people on here, including myself that can help you out. I can even remote tune it for you from here. For the distance you're traveling, and the money you're spending, your own software package is well worth it.
just came back for the 8th time from tunner(last one) i think i'm back to day one with tune,he has taken out the speed density tune, he said that he has informed with experts and with that cam i am going to have to live with the surging-bucking. i am going to have to find a tuner in the montreal or toronto area(probrobly at champion motors ) were i bought most of my parts, i think its like 1600km one way trip
,he has taken out the speed density tune, he said that he has informed with experts and with that cam i am going to have to live with the surging-bucking. i am going to have to find a tuner in the montreal or toronto area(probrobly at champion motors ) were i bought most of my parts, i think its like 1600km one way tripLast edited by DrkPhx; Sep 13, 2010 at 09:48 PM.
If you decide to go with EFILive, let me know - I'd be willing to help you out! I've done my share of email tuning... takes a little more time, but it works! Time to seriously consider doing it yourself - You won't be getting ripped off by idiots anymore, and you will have the satisfaction of accomplishment.
I'm running a very similar cam and I was able to tune it myself. All I've done so far is a good bit of MAF tuning and went ahead and did a quick RAF tune as well and it idles pretty well at 900 rpm. My point being I would think that if a first time noob like myself can get a similar setup to run well, it must not be impossible 
I do have a little surge below 1800, but not bad at all.
If all mechanical possibilities have been ruled out, maybe the new larger injectors are not setup properly?
I do have a little surge below 1800, but not bad at all.If all mechanical possibilities have been ruled out, maybe the new larger injectors are not setup properly?
Thread Starter
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From: NB Canada
i am going to consider the option of byuing the equip. to do myself, and study it over the winter and try in spring, one question- when i go to tune, i would be strarting with the tune thats in it know and not with the stock tune? when i had the enhanced speed density tune the car was perfect for starting and would never stahll anytime(never) but had bucking and surging, now that he put it back on the regular tune it doesn't start great and idle sounds 
like if timming was way back, so it goes to show that with the proper tunning idle and start can be achieved, its the frigen surging im after, the specs on cam is comp cam 236/242 .590/.612 lift with 1.7(i have 1.85) and 112.
like if timming was way back, so it goes to show that with the proper tunning idle and start can be achieved, its the frigen surging im after, the specs on cam is comp cam 236/242 .590/.612 lift with 1.7(i have 1.85) and 112. Last edited by 35th camaro; Sep 14, 2010 at 10:53 AM.
I'm at the opposite end of the country, there were no tuners within 6 hours of my location.
If you have the PE part of your tune done by others you won't hurt the motor, you can work on the hardest part......drivability.
The good part about working in that area of the tune is you most likely won't hurt the motor.
You have had good advice here, you don't have any choice as it seems you don't have have a good tuner nearby.
Make the investment in the future, this **** is not going away. Also don't worry about the cost of the software & hardware to tune, your education to learn how use it properly is much more important & costly.
If you have the PE part of your tune done by others you won't hurt the motor, you can work on the hardest part......drivability.
The good part about working in that area of the tune is you most likely won't hurt the motor.
You have had good advice here, you don't have any choice as it seems you don't have have a good tuner nearby.
Make the investment in the future, this **** is not going away. Also don't worry about the cost of the software & hardware to tune, your education to learn how use it properly is much more important & costly.
Your combo sounds like an easy tune, so I would be willing to bet there is a bad sensor or something isn't put together right. Could be as easy as the wrong cam gear/reluctor wheel. Seen that a few times in the past.People build these with a 08+ cam gear which makes drivability/startup problems.
Thread Starter
TECH Apprentice
Joined: Aug 2009
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From: NB Canada
in no way i am putting down my tunner guy, just that i can't afford to keep going , i have lost my whole summer travelling and not driving car to mutch in between trips, until i get it tunned by someone else or myself or find a probleme with my setup, then i will be able to comment on his ability.
Just keep in mind that sometimes, no matter what you do, you cant get the bucking and surging all the way out. You can soften it but it will ultimately depend on your definition of acceptable. When mine was a M6 402 on spray, I ran a 242/252 cam. It wanted to buck and surge between 1700-1900 RPM. The way that I was able to soften it up was taking out a shitload of timing in that area (stock has like 40*IIRC and I had it down to 17*) and run a little richer than stoich (like 13.5 ish).
The first thing that I would do If I were you is take those rockers off and put the stockers back on. .650 lift is not helping your valvespring life and is likely not getting you much in the way of extra power either. The stock rockers are also much lighter and will likely provide better valve control over 6500 RPM due to the weight savings.
Another option is to switch to an auto with a decent stall. This problem will disappear completely and the car will perform better.
Hope this helps.
The first thing that I would do If I were you is take those rockers off and put the stockers back on. .650 lift is not helping your valvespring life and is likely not getting you much in the way of extra power either. The stock rockers are also much lighter and will likely provide better valve control over 6500 RPM due to the weight savings.
Another option is to switch to an auto with a decent stall. This problem will disappear completely and the car will perform better.
Hope this helps.
Thread Starter
TECH Apprentice
Joined: Aug 2009
Posts: 389
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From: NB Canada
going to a auto is not a option, i have the 1.85 because they came with crans adjustable kit i had for my ls1, if i go back to stock then i loose my adj.. the last time at tunner he tried taking out lots of timming at that rpm and it got worst, then added some and stayed the same as before???