surging prob on 383 lt1
Thread Starter
Staging Lane
Joined: Oct 2010
Posts: 63
Likes: 0
From: oklahoma city ok.
surging prob on 383 lt1 Ok I just installed# 42lb bosch 3 injectors had the pcm tuned by pcmforless and drove it around the block and its surging and not responding well I think it might be the plugs but not sure... I went to start it today and it wont start plz help
TECH Apprentice
Joined: May 2010
Posts: 333
Likes: 1
From: Arkansas
It could be running lean and then dumping fuel to try and correct it and is where the surge is coming from. I added a little to my maf tables at idle. Fixed my horrible surge and idle issues. Good luck
I had a LOT of problems with pcmforless before I gave up on them. Contact them and see what they say.
All we have for info on the car though is the little you have in your "my garage" tab.
I see an MSD opti, did you install a degreed damper with keyed hub and fabricate a pointer so you could verify the timing adjustment? If not the adjustment could be wrong causing the timing to be substantially different than the tuner commanded in which case it would be very hard for any tuner to get dialed in even with the car in person till they figured out the timing offset.
Depending on the intake tract a descreened MAF can messup readings, if there is a sharp curve just before the MAF the flow is not even across the MAF cross section.
All we have for info on the car though is the little you have in your "my garage" tab.
I see an MSD opti, did you install a degreed damper with keyed hub and fabricate a pointer so you could verify the timing adjustment? If not the adjustment could be wrong causing the timing to be substantially different than the tuner commanded in which case it would be very hard for any tuner to get dialed in even with the car in person till they figured out the timing offset.
Depending on the intake tract a descreened MAF can messup readings, if there is a sharp curve just before the MAF the flow is not even across the MAF cross section.
TECH Fanatic
Joined: Feb 2006
Posts: 1,025
Likes: 1
From: CT/NJ
The one experience I had with a PCMforless tuned car led me to believe that at least their mail order tunes are crap. That car would start and stay running at least though so, maybe you have something other than a tune problem going on with yours.
We need more info if we are going to be able to help you narrow it down. Now that it will not start, does it have spark? Fuel pressure? Injector pulse? Security light staying on?
We need more info if we are going to be able to help you narrow it down. Now that it will not start, does it have spark? Fuel pressure? Injector pulse? Security light staying on?
Thread Starter
Staging Lane
Joined: Oct 2010
Posts: 63
Likes: 0
From: oklahoma city ok.
Ok guys this is what I can give you it will crank but not start, and the security light comes on sometimes and I have to lock the car and leave it alone for bout 25 min then I unlock it and its fine, the time it started after intslling the new tune it idled really rough I had to keep on the throttle a lil to keep it running, and about the msd opti, all I did was take it outta the box and put it on, I didn't know I was sposed to put all that mess with it, it has a **** with a slot I did not adjust the timing yet.and with my cai it a factory intake with a k
&n air filter, maybe this will help out a little bit? If you need more spacific info let me know. Thanks for all the help
&n air filter, maybe this will help out a little bit? If you need more spacific info let me know. Thanks for all the help
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Thread Starter
Staging Lane
Joined: Oct 2010
Posts: 63
Likes: 0
From: oklahoma city ok.
ok i pulled my plugs out and they were soaked and gap was at 60 so i put new ones in with gap at .045 and it started right up but again with the rough idle... so i called pcm forless and they said its most likely a vaccum leak but i dont know where it could be leaking at i blicked off my egr whe i built the motor and i silliconed the vaccum spot above the pcv but thats the only places that i know of that could be the culprit.. if anyone has any info plz feel free to help
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Are any of the plug wires crossed? Some cars run like **** and some cars dont run.
My pcmforless tune like stated above, the car runs, it drives, but its not perfect, better then a stock tune, but not the best. I give some leeway on the mail order, you cant expect to get a perfect dialed in tune when they see the car in email form. I wouldnt think that pcmforless could have the tune so far off that your car wont run, its possibly, but theyve tune alot of cars and im sure the tune you got would make it run, just not as good as it could.
Are 42lb injectors what you need? i dont know what to large of injectors could do but perhaps thats why?
People always want to blame the tuner, But in order to do this you have to get your facts in order and make sure nothing on the car is a miss. My buddy had this happen to his mustang. Went off on the tuner...turned out one of his intercooler pipes had the bottom of a connector slightly come off, wasnt noticeable from any angle. And someone else found the problem after the tuner looked the car over for half a day.
Just saying...check check and recheck.
My pcmforless tune like stated above, the car runs, it drives, but its not perfect, better then a stock tune, but not the best. I give some leeway on the mail order, you cant expect to get a perfect dialed in tune when they see the car in email form. I wouldnt think that pcmforless could have the tune so far off that your car wont run, its possibly, but theyve tune alot of cars and im sure the tune you got would make it run, just not as good as it could.
Are 42lb injectors what you need? i dont know what to large of injectors could do but perhaps thats why?
People always want to blame the tuner, But in order to do this you have to get your facts in order and make sure nothing on the car is a miss. My buddy had this happen to his mustang. Went off on the tuner...turned out one of his intercooler pipes had the bottom of a connector slightly come off, wasnt noticeable from any angle. And someone else found the problem after the tuner looked the car over for half a day.
Just saying...check check and recheck.
More information is Needed...what size cam,converter,are you sure the valves are adjusted correctly,triple check and make sure ur wires are correct,check again for a vacuum leak..could be throttle body to intake leak..Are you 100% sure the opti is installed correctly?
Thread Starter
Staging Lane
Joined: Oct 2010
Posts: 63
Likes: 0
From: oklahoma city ok.
I have a custom ground cam from erson cams it is a 548 lift cam with a 108 lsa and I put 42s on it cus I plan on changing to a 52mm TB just not sure on brand yet.... I was thinking could my tps sensor be bad? I'm not an lt1 pro but I am willing to learn as much as I can I've done most the work myself except put the motor together, the machine shop I used did that and ajusted everything. I just installed it into the car and put the bolton's on.... I wish I had a freind that knew about this stuff and could show me and or help me... I'm a hands on learner so if there is anyone in the okc area plz contact me if your willing to help.... After I get her fixed I wanna sell her and get an ls1 there is more ppl willing to help and tune if you had an ls1... Sorry bout going on my little rant there lol.... And I will check my wires again...
Thread Starter
Staging Lane
Joined: Oct 2010
Posts: 63
Likes: 0
From: oklahoma city ok.
oh and im not running a converter i have a 6 spd and yes on the opti.. i drove the car for 3 weeks and it did fine untill the fuel filter got clogged (it was the original) and ever since then its been running like crap it didnt start surging till after i changed the filter,
does anyone know of a tuner in the oklahoma area that is worth a damn? the guy i was gonna go to sold his dyno and is workin goutta his house but only doing mail orders.. its www.fastchip.com but now i have no clue where to go.. i dont wanna hve to take my car outta state if i dont have to
does anyone know of a tuner in the oklahoma area that is worth a damn? the guy i was gonna go to sold his dyno and is workin goutta his house but only doing mail orders.. its www.fastchip.com but now i have no clue where to go.. i dont wanna hve to take my car outta state if i dont have to
