speedmachine

iTrader: (1)

hello there

just finished putting an ls1 into an 1989 iroc... the engine will not start by istself but with a litle throttle it willl start, however, if you do not keep you foot slightly on the gas it just dies... the ls1 as attached to a stick, and now its attached to my 700r4, maybe its not used to having a converter on it and thats why it dies??? i have hp tuners.. what should i do to try and correct this.

pdsq98gt

Need more info on the engine. Is it stock or modified? Dbw or cable throttle? If the motor has been sitting for a while, make sure the injectors aren't gummed up.

speedmachine

iTrader: (1)

1999 ls1 5.7 with tr 224 cam ported heads ls6 intake was running not 3 months ago in another car [tremec 6 speed]

did a head swap to the zo6 c&c ported prc heads, used same ls6 intake, did an asp underdrive pulley and attached it to my 700r4 in my iroc... i am using a manual tune becuase it is easier to pretend the 700r4 is a stick then deal with all of the 4l60E tables that wont be satisifed.

it will not start by itself, if i give it a little gas it will fire right up but if i take my foot off of the throttle it imediatly dies.... the most interesting part is that when i first started it it was running fine but when i added water to the engine, maybe 30 seconds later through the upper rad hose it immediatly stalled out... its almost like it was so close to stalling that with the added centrifical draw from the water against the impeller in the pump that it stalled it. Call me totally crazy but it was running and idleing just fine but only before i had the water in the engine.

speedmachine

iTrader: (1)

seeing as that it runs with throttle and ive moved the car several hundred feet i dont think the injectors are clogged.. and the car is a cable throttle

garys 68

iTrader: (1)

Is the IAC working?

pdsq98gt

You may just need to dial in the runing airflow tables. How are the fuel trims looking?

Pop N Wood

iTrader: (1)

Don't forget the basics before digging into computer tools. Vacuum leaks? Dirty throttle body? PCV and EGR working? IAC motor functioning? Fouled plugs? MAP-MAF all hooked up properly? Nothing got disconnected?

Loudpipe

iTrader: (11)

i was going to say vacuum leak. my carbed 6.0 did the same thing it was a intake leak.

Old Geezer

iTrader: (3)

You have HP Tuners, why not datalog it, and see what pops up??

speedmachine

iTrader: (1)

the iac works, how many inches of vacume should the intake have so i can check it. used brand new intake gaskets, the plugs are brand new TR55 IX NGK plugs, everything is connected, throttle body is clean, the pcv is all hooked up.

i decided to keep my foot on the pedal keeping the rpms at about 1500 to 2000 range until she warmed up to operating temperature and then she would idle nicely and run great.... it seems to idle just fine without any assistance when warm... but i let the car sit for a few hours and i was back to no idleing and cold.

i dont have any codes... not yet at least.... i will be welding 2 o2 sensor bungs into the exhaust to hook up my LM2 and check the air fuel, it seems like it might be a little rich... which tables should i try to correct this problem with?

i will check for other vacume leaks but i dont think i have any as far as i can tell so far.

pdsq98gt

Go onto the hptuners forum and look for russk's idle config. This will get your running air flow table set. Then you need to dial in he VE table and your MAF curve if you're runnng a MAF.

reidtk

What ended up being the problem I am having same issue right now getting fuel, spark, everything.

G Atsma

OP hasn't been here in 2 years

reidtk

damn yea my car isn’t firing up right now only when foot is on gas and turns off right after I let go.

01CamaroSSTx

iTrader: (3)

DBC or DBW?

reidtk

It is DBC

01CamaroSSTx

iTrader: (3)

Is this a stock engine or mods and have you checked your IAC's? You'll want your idle air control counts to be under 60 and may need to to crack the throttle blade open some more to allow more air in to get it to idle correctly. Make small adjustments like a slight turn and hopefully you have HPT so you can monitor the changes. Could also be a bad IAC or possibly the TPS or even a dirty MAF sensor..GL

Kawabuggy

iTrader: (1)

Two posters above have hit on things that are absolutely essential to check/test/verify BEFORE you start hacking away at the tune.. You MUST make sure that mechanically nothing is wrong... If you have a vacuum leak ANYWHERE and you go into the tune to try and "fix" this problem.. You will create an unsolvable problem, be chasing your tail as you descend into the rabbit hole... I know from experience. I chased a poor idle issue for MONTHS.. I made at least 50 different iterations of the tune, burning it in each time, never to achieve success.. I even had people on the web site assisting me with suggestions on changes to the tune, and even had some guys offer up another alternate tune to try.. In the end, only through sheer luck was I able to finally figure out my problem... My IAC (brand new-just installed) was faulty. I only figured this out because it would show 320 idle air counts on a cold start... I realized the computer was commanding more idle air and I stupidly believed that the IAC motor was opened all the way and the engine was still needing more.. So after countless IDLE CONFIG attempts, VE table tuning, MAF table tuning, Open loop fuel table changes, timing changes, and many other countless wasted changes did I finally figure out the real problem.. I had the throttle body off the intake.. In my hand.. With HP tuners hooked up. Through the controls on the scanner I was commanding the IAC to open and close and it would not move... I then ordered another IAC off the internet-installed it-and then the engine was idling at 3500.. nothing I could do to get the idle down.. I thought I had ruined the car... I then swapped a used GM throttle body from another engine onto the car,... Burned a completely stock tune to get rid of all the trash I introduced chasing the problem.. With that used throttle body, and a stock tune, and basic changes, I was up and running in 30 minutes, and about 5 iterations of changing the tune and I was DONE... It can't be stressed enough that if you have a mechanical problem it's easy to get lost in the tune changing fog.... I would check for codes with a REAL SCANNER.. HP Tuners is NOT RELIABLE at all as it relates to pulling codes and data from your PCM.. Use a high end, or higher end scanner such as a Snap On Solus, or Modus.. If the scanner does not cost at least $3000, you may not be getting all the data out of the PCM to drill down on your problem... Seriously.. The hand held several hundred dollar code readers typically will not show you the entire picture.. Leaving you guessing as to what you really need. Also.. every time you start to make changes on the tune.. READ and save the file at the beginning of the day so that if you need to revert back to a previous iteration you can do so easily. And.... if you make several changes and can't find success... Maybe it's not in the tune! Don't be like me wasting MONTHS of time chasing a minor idle issue that turns out to be outside the tune.

Kawabuggy

iTrader: (1)

You may be on to something here.. The STICK trans tune will have less BRAF because there is less of a drag on the engine when idling.. Going to an automatic trans with a torque converter is going to require BRAF changes as the engine will *most likely* need more idle air. You can start by scanning the engine on a cold start with the IDLE CONFIG by RUSS K and see what the engine is actually wanting to idle.. Since you are already stating the engine will not start without a little throttle pedal.. I'd start by turning the throttle blade screw in at least 1/4 turn to open the blade a little bit, and then do the idle config. OR... alternatley.. just highlight the columns for 176 and lower (as you said it idles when hot so no need to adjust the HOT columns at this time) on the BRAF table and multiply by 1.10 which will add 10%. Burn that in and then try to start it to see if will idle. Have your scanner recording your cold start attempt so that if it does idle, you can get good data to put into the BRAF table after the engine gets up to operating temp.

Keep in mind a 224 cam is going to require quite a bit LESS fueling in the 400-800-1200 columns.. If the engine was not tuned for this cam previously... You may want to reduce the 400 column by 20%, 800 column by 18%, and the 1200 column by 15%.. IF this engine was already tuned for this cam-DO NOT CHANGE ANY OF THE FUELING TABLES YET and just focus on the BRAF table... A cold start while data logging with a wideband O2 could save you a lot of trouble.... Unless... Like me... You have a wideband that will NOT give accurate data until the vehicle has been driven at least 15 minutes and gotten the O2 sensor up to full temp.. .My AEM wideband is TRASH until the car is as hot as it can get with the fans running, at thermostat operating temp.. Seriously... anything less than 15 minutes of drive time gives TRASH data that if you make changes to the tune based off of... you will be CREATING problems not solving them...

reidtk

[QUOTE=Kawabuggy;20373316]You may be on to something here.. The STICK trans tune will have less BRAF because there is less of a drag on the engine when idling.. Going to an automatic trans with a torque converter is going to require BRAF changes as the engine will *most likely* need more idle air. You can start by scanning the engine on a cold start with the IDLE CONFIG by RUSS K and see what the engine is actually wanting to idle.. Since you are already stating the engine will not start without a little throttle pedal.. I'd start by turning the throttle blade screw in at least 1/4 turn to open the blade a little bit, and then do the idle config. OR... alternatley.. just highlight the columns for 176 and lower (as you said it idles when hot so no need to adjust the HOT columns at this time) on the BRAF table and multiply by 1.10 which will add 10%. Burn that in and then try to start it to see if will idle. Have your scanner recording your cold start attempt so that if it does idle, you can get good data to put into the BRAF table after the engine gets up to operating temp.

Keep in mind a 224 cam is going to require quite a bit LESS fueling in the 400-800-1200 columns.. If the engine was not tuned for this cam previously... You may want to reduce the 400 column by 20%, 800 column by 18%, and the 1200 column by 15%.. IF this engine was already tuned for this cam-DO NOT CHANGE ANY OF THE FUELING TABLES YET and just focus on the BRAF table... A cold start while data logging with a wideband O2 could save you a lot of trouble.... Unless... Like me... You have a wideband that will NOT give accurate data until the vehicle has been driven at least 15 minutes and gotten the O2 sensor up to full temp.. .My AEM wideband is TRASH until the car is as hot as it can get with the fans running, at thermostat operating temp.. Seriously... anything less than 15 minutes of drive time gives TRASH data that if you make changes to the tune based off of... you will be CREATING problems not solving them...[/QUOTE
]


Just changed the sensors and went for the first start huge back fire. I don’t know what it is at this point smh.