My new motor idles a bit high..ideas? Pro's come on in?
06-26-2012, 08:53 PM
#1
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My new motor idles a bit high..ideas? Pro's come on in? Forged 383 lt1,42# SVO's,Le1, 236/238 .555/.561 110lsa...
i have triple checked for vac leaks...have re-torqued the manifold
,My IAC counts are in the 20-40 range, i've drilled the IAC port to 1/4 in the stock but bored 52mm TB after being advised to by tuner and per this thread http://www.camaroz28.com/forums/lt1-...ameter-699051/
and doing so has helped somewhat ..mostly with the blms and smoothing idle and throttle response,My TPS is adjusted to .49-.51 for some reason it wont register at .50 like 93's should read its either .49 or .51....
has had a ton of email fine tuning and reflashes... it has been converted to a heated o2 system W/brand new Bosch O2's (i know use delcos right?)... it stays in closed loop like its supposed to.....NO DTC's. I've even used a propane torch (NO not ignited) to check for an indication of a vac leak with no such luck..
its commanded to idle at 875 but dances between 950-1050, when u shift outta park into gear it will idle at 8xx then slowly idle back up to 950-1050...
i dont ******* get it...
i have logs but cant figure out how to post them here..
i guess the idle could be worse but damn.
i have triple checked for vac leaks...have re-torqued the manifold
,My IAC counts are in the 20-40 range, i've drilled the IAC port to 1/4 in the stock but bored 52mm TB after being advised to by tuner and per this thread http://www.camaroz28.com/forums/lt1-...ameter-699051/
and doing so has helped somewhat ..mostly with the blms and smoothing idle and throttle response,My TPS is adjusted to .49-.51 for some reason it wont register at .50 like 93's should read its either .49 or .51....
has had a ton of email fine tuning and reflashes... it has been converted to a heated o2 system W/brand new Bosch O2's (i know use delcos right?)... it stays in closed loop like its supposed to.....NO DTC's. I've even used a propane torch (NO not ignited) to check for an indication of a vac leak with no such luck..
its commanded to idle at 875 but dances between 950-1050, when u shift outta park into gear it will idle at 8xx then slowly idle back up to 950-1050...
i dont ******* get it...
i have logs but cant figure out how to post them here..
i guess the idle could be worse but damn.
Last edited by defaultexistence; 06-26-2012 at 09:35 PM.
06-26-2012, 09:55 PM
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When i first had mine tuned by pcmforless mine did the same thing. Kept idling up to about 1100 and would not come down. I called them and they said send it back. They said that the 93 had more than one base program and some of the 93's did not like some of them. So i sent it back and a week later i was all good. Who does ur programing?
06-26-2012, 10:16 PM
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When i first had mine tuned by pcmforless mine did the same thing. Kept idling up to about 1100 and would not come down. I called them and they said send it back. They said that the 93 had more than one base program and some of the 93's did not like some of them. So i sent it back and a week later i was all good. Who does ur programing?
It would be nice to hear it idle as commanded..
I wonder why the tps won't register at .50..? Bad maybe ? Bad IAC? ...
Last edited by defaultexistence; 06-26-2012 at 10:22 PM.
06-26-2012, 11:01 PM
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I just did a cc503 and heads, my tps registered .59-.61 consistantly with 0% throttle angle. Do u have 0%? then i did the swap and i am in the .89-.91 range with 0%. I do not have the computer tuned yet, i will be sending it in next week. But mine changed for some unknown reason. Send ur memcal chip to pcmfor less or give them a call, they do great work i' sure they can help u.
06-27-2012, 05:10 AM
#6
Don't sweat the TPS voltage that much. The PCM will target anything between .23v and .9v at closed idle then prorate the +4v from there. Most people (unwillingly) target .5-.6v simply because it puts the voltage in the range with the largest margin of error.
Last edited by RamAir95TA; 06-27-2012 at 05:22 AM.
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06-27-2012, 10:29 AM
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It was a tad worse at stock diameter ..and BLM's wERe worse..IAC's were 60+, At 1/4" It helped lower the idle by about 75rpm, cleaned up the BLM's...
Just like in Jake JR's thread in post #1..
I'll try restricting it but IAC's counts will rise and BLM's split again...
Just like in Jake JR's thread in post #1..
I'll try restricting it but IAC's counts will rise and BLM's split again...
06-27-2012, 11:01 AM
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PCM can read 300 rpm off I have been told by madtuner and pcmforless that the idle range can be set in the tune but may idle 300 rpm higher than it asks for.
when asked if I could lower it in the tune Ion said in gear it would drop to the desired computer rpm but in neutral it revs up to 1000+.
So Im in the same game as you, my idle is around 1000 computer set to 900.
So I have been having issues with my plugs fouling and O2's going bye bye within a hour of install. ( Yeah Bosch, I know Delco's) but am in the process of hopefully working with Ed Hitechtuning to re format my tune.OL,SD
wonder if Ion is doing something in the tunes, I compared mine to a stock tune and some of my tables are still same as stock but a lot of fuel was added along with timing. funny how you had the same issue.
maybe big cams don't like CL,MAF tuning?
when asked if I could lower it in the tune Ion said in gear it would drop to the desired computer rpm but in neutral it revs up to 1000+.
So Im in the same game as you, my idle is around 1000 computer set to 900.
So I have been having issues with my plugs fouling and O2's going bye bye within a hour of install. ( Yeah Bosch, I know Delco's) but am in the process of hopefully working with Ed Hitechtuning to re format my tune.OL,SD
wonder if Ion is doing something in the tunes, I compared mine to a stock tune and some of my tables are still same as stock but a lot of fuel was added along with timing. funny how you had the same issue.
maybe big cams don't like CL,MAF tuning?
06-27-2012, 11:19 AM
#11
FWIW...my 383 with lunati voodoo 60122 (231/239) idles right at 850-900 with a stock TB bored out to 52mm....the IAC port has not been drilled. My mail order PCM for less tune is pretty good.
How soon does the high idle happen? After it goes into closed loop and the O2's start working? As you know, the Boschs don't like LT1's very much, I would strongly consider the right O2's that came from the factory AC Delco
Not sure why anyone would NOT run a factory O2 sensor when they are cheaper than any O2s you get at a part store that are known to give issues. My 2 cents
^Both you guys have Bosch O2s and high idle....coincidence?
How soon does the high idle happen? After it goes into closed loop and the O2's start working? As you know, the Boschs don't like LT1's very much, I would strongly consider the right O2's that came from the factory AC Delco
Not sure why anyone would NOT run a factory O2 sensor when they are cheaper than any O2s you get at a part store that are known to give issues. My 2 cents
^Both you guys have Bosch O2s and high idle....coincidence?
06-27-2012, 11:22 AM
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Yeah only mine drops to commanded idle at first when put into gear then almost instantly begins to rise back to the higher idle, take it outta gear it shoots up to 1075-1150 for a couple seconds then settles back at 975-1050ish .. In OL it idles high cold..like 1000-1150 As soon as it hits temp & CL it settles down to the 975+^^^^ ...And yes I plan on getting the delcos... Payday ain't here yet
06-27-2012, 11:32 AM
#13
PCM for less
06-27-2012, 07:42 PM
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Welp.. Slowly restricted the IAC hole and just as I thought... Iac Count went up to 100's and idle dipped to near commanded then crept back up as it settled.. So the hole don't mean ****, ultimately the iac does what it must to hold idle @ 950-1125+/-
06-27-2012, 10:27 PM
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Many things can cause the idle to not properly be at the set rpm. Timing has a large effect on how well it idles and maintains that idle. A motor with different displacement and a different cam can greatly change how much timing is needed to keep the rpms up when a load is applied, and also how much needs to be retarded when a load is taken off. A good bit of logging is required to get a new setup working properly.
Get a good set of o2's on the car and let your tuner have time to get it right.
Get a good set of o2's on the car and let your tuner have time to get it right.
06-28-2012, 08:24 AM
#19
