iac and stall during cold
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Joined: Feb 2001
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From: canada
iac and stall during cold
when i started the engine this morning, temp outside 8deg cel., and drove down my 300ft driveway and when i stopped, the engine rpm drops and the engine almost stalls. the ecm responsed and jumps the idle up to prevent stall. this only happens for the first while until the engine starts to warm up. on warm idle my iac is at about 50 and the rpm is about 750 as per the command setting. in closed loop my idle fuel is at 128 and my fuel curve is tuned with the blm locked. the chip did have the blm locked during this episode and the laptop was beside me. i did watch the iac counts when this happened and they did jump from 85 to 146. i am sure i have no vaccum leaks, i checked with propane. this will happen on for the next several intersections unit the coolant temp gets warmer. at engine operating temp this is not a problem.
if i set the iac vs coolant temp to 0 for a warm engine then adjust the throttle plates to get may command idle would this be the proper way to set the iac vc coolant chart after programmed for cold coolant?
by the way i removed my performer intake and replaced it with the weiand single plane and pablo was right about not loosing any torque at low rpm. i retuned my fuel curve and intake is much better for response than the dual plane was at all rpms! just an aside to my cold idle problem. i had this cold idle problem with both intakes.
383 stroker, 64cc 23deg trickflow heads c/w weiand xcelerator single plane, adapter, cam is an extreme 4x4 comp. Cam. 12-235-2 grind ( .447/.462 lift, duration 210 218 lift @50, 111 lobe separation) . unit has hypr. Flattop floating pistons, eagle cast crank, 5.7eagle rods. 10.2:1 comp. Headers c/w 2.5” flowmaster exhaust. 16147060 pcm, $85def
454tbi 80lbinjectors
if i set the iac vs coolant temp to 0 for a warm engine then adjust the throttle plates to get may command idle would this be the proper way to set the iac vc coolant chart after programmed for cold coolant?
by the way i removed my performer intake and replaced it with the weiand single plane and pablo was right about not loosing any torque at low rpm. i retuned my fuel curve and intake is much better for response than the dual plane was at all rpms! just an aside to my cold idle problem. i had this cold idle problem with both intakes.
383 stroker, 64cc 23deg trickflow heads c/w weiand xcelerator single plane, adapter, cam is an extreme 4x4 comp. Cam. 12-235-2 grind ( .447/.462 lift, duration 210 218 lift @50, 111 lobe separation) . unit has hypr. Flattop floating pistons, eagle cast crank, 5.7eagle rods. 10.2:1 comp. Headers c/w 2.5” flowmaster exhaust. 16147060 pcm, $85def
454tbi 80lbinjectors
Thread Starter
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Joined: Feb 2001
Posts: 166
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From: canada
<font face="Verdana, Arial" size="2">Originally posted by prscarf:
when i started the engine this morning, temp outside 8deg cel., and drove down my 300ft driveway and when i stopped, the engine rpm drops and the engine almost stalls. the ecm responsed and jumps the idle up to prevent stall. this only happens for the first while until the engine starts to warm up. on warm idle my iac is at about 50 and the rpm is about 750 as per the command setting. in closed loop my idle fuel is at 128 and my fuel curve is tuned with the blm locked. the chip did have the blm locked during this episode and the laptop was beside me. i did watch the iac counts when this happened and they did jump from 85 to 146. i am sure i have no vaccum leaks, i checked with propane. this will happen on for the next several intersections unit the coolant temp gets warmer. at engine operating temp this is not a problem.
if i set the iac vs coolant temp to 0 for a warm engine then adjust the throttle plates to get may command idle would this be the proper way to set the iac vc coolant chart after programmed for cold coolant? also, my iac steps vs coolant temp chart is much lower than what the iac is doing at warm closed loop idle, why? chart at 83deg c is 18 and my iac is at 36 on the scanner at 675rpm
by the way i removed my performer intake and replaced it with the weiand single plane and pablo was right about not loosing any torque at low rpm. i retuned my fuel curve and intake is much better for response than the dual plane was at all rpms! just an aside to my cold idle problem. i had this cold idle problem with both intakes.
383 stroker, 64cc 23deg trickflow heads c/w weiand xcelerator single plane, adapter, cam is an extreme 4x4 comp. Cam. 12-235-2 grind ( .447/.462 lift, duration 210 218 lift @50, 111 lobe separation) . unit has hypr. Flattop floating pistons, eagle cast crank, 5.7eagle rods. 10.2:1 comp. Headers c/w 2.5” flowmaster exhaust. 16147060 pcm, $85def
454tbi 80lbinjectors
</font>
when i started the engine this morning, temp outside 8deg cel., and drove down my 300ft driveway and when i stopped, the engine rpm drops and the engine almost stalls. the ecm responsed and jumps the idle up to prevent stall. this only happens for the first while until the engine starts to warm up. on warm idle my iac is at about 50 and the rpm is about 750 as per the command setting. in closed loop my idle fuel is at 128 and my fuel curve is tuned with the blm locked. the chip did have the blm locked during this episode and the laptop was beside me. i did watch the iac counts when this happened and they did jump from 85 to 146. i am sure i have no vaccum leaks, i checked with propane. this will happen on for the next several intersections unit the coolant temp gets warmer. at engine operating temp this is not a problem.
if i set the iac vs coolant temp to 0 for a warm engine then adjust the throttle plates to get may command idle would this be the proper way to set the iac vc coolant chart after programmed for cold coolant? also, my iac steps vs coolant temp chart is much lower than what the iac is doing at warm closed loop idle, why? chart at 83deg c is 18 and my iac is at 36 on the scanner at 675rpm
by the way i removed my performer intake and replaced it with the weiand single plane and pablo was right about not loosing any torque at low rpm. i retuned my fuel curve and intake is much better for response than the dual plane was at all rpms! just an aside to my cold idle problem. i had this cold idle problem with both intakes.
383 stroker, 64cc 23deg trickflow heads c/w weiand xcelerator single plane, adapter, cam is an extreme 4x4 comp. Cam. 12-235-2 grind ( .447/.462 lift, duration 210 218 lift @50, 111 lobe separation) . unit has hypr. Flattop floating pistons, eagle cast crank, 5.7eagle rods. 10.2:1 comp. Headers c/w 2.5” flowmaster exhaust. 16147060 pcm, $85def
454tbi 80lbinjectors
</font>
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Joined: Feb 2001
Posts: 166
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From: canada
i resolved this problem myself. now my engine runs without ever stalling during cold coolant temp when i make a stop. the iac is at "0" when the engine is warm and at 650rpm idle. it also follows the command idle.
Thread Starter
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Joined: Feb 2001
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From: canada
<font face="Verdana, Arial" size="2">Originally posted by afgun:
What did you do to resolve the problem? Share with the group
</font>
What did you do to resolve the problem? Share with the group
</font>
Set the iac vs coolant to “0”.
Removed Iac and extended pintle to full out then reinstalled iac (zero iac air)
Started engine and set to desired idle at normal operating temp.
Reburned chip for desired command idle vs temp –25rpm at normal operating temp. this keeps iac at zero steps.
Changed iac vs coolants steps for just the cold coolant settings and left others at zero.
I did reply to this string yesterday but I guess it didn’t take.
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