Iregular idle

[Slow355Participant Victoriahectic spec 355 vs ss ute View build HERE Member since: March 2, 2015 Posts: 322]

So for the last year (yes i am lazy) every now and then my ute refuses to idle. No idea why, as has done 400000 kms as a new 355 and same tune throws no fault codes etc. Started doing it after had ute resprayed, panel beater let the batterie go flat as a tac and had to replace as brand new batterie now.

Sometimes it drives fine, start it drive it, thrash it, cruise it runs like a charm. Will be fine for weeks.

Then ill randomly get in, start it idles fine, then drive out of car park and stalls as soon as i stop, unless i catch it and hold brake and hold revs around 900.

If i dont it will drop to 200 than flare to 1500 do this a couple of times then cut out, if for example you were at the lights or cruising with no load on the motor. However idles fine if in park.

I have just learnt to deal with it, ie drive with two feet as if i catch it and hold idle steady with my foot, and slowly release foot from the loud pedal it will idle fine at lights, until the next set.

Any ideas? Was fine before respray then started doing it? Thinking maybe try changing filter as in past has run shit with dirty filter.

 

 

munch munch ls1s for lunch
Best 1/4 mile 13.1@105mph 60ft-1.8sec Reaction time .8 sec 0/100-4.8sec

[ImmortalityParticipant 97 HSV Senator 185i 02 VX L67 Calais View build HERE Member since: August 31, 2015 Posts: 535]

Does it drive fine when it has this idle problem?

Could be a number of things, one that springs to mind is a dodgy VSS (vehicle speed sensor) although if this is faulty it does normally throw a fault code.  The one on my Senator is a bit dodgy and won’t idle when it plays up.

[Slow355Participant Victoriahectic spec 355 vs ss ute View build HERE Member since: March 2, 2015 Posts: 322]

Na still drives fine just no ability to idle.

munch munch ls1s for lunch
Best 1/4 mile 13.1@105mph 60ft-1.8sec Reaction time .8 sec 0/100-4.8sec

[VS 355 UTEParticipant QLD96 vs v8 ute View build HERE Member since: January 13, 2016 Posts: 141]

Sounds like it could be the IAC,if your still using it.Mine used to hunt up and down at lights all the time,major pain in the arse.I pulled it apart,cleaned and checked it was working but it could never react quick enough.This was with a 286 Hyd cam in the 304.Blocked mine off and just use the adj throttle blade for idle and ecu uses timing to compensate for any load.Works great and no more up and down idling.

Might be worth giving it a clean,could be sticking every so often.

 

At first i thought TPS but it would be playing up all the time.Mine needed re setting once when battery was dead for some time.

 

• This reply was modified 8 years, 9 months ago by  VS 355 UTE.

[Slow355Participant Victoriahectic spec 355 vs ss ute View build HERE Member since: March 2, 2015 Posts: 322]

Yea thought i should give it a clean also i put it in a dumb spot i didnt want to weld the boss to plenum as was worried about warping it so it runs off a hose and i know the hose did make tuning it harder, but saying that ran like a dream for years. Maybe the fact it doesn’t get driven much allows it to stick.

Ignore the retarded intake lol was simply to get the first tune, but see how the boss is on back of catch can with a hose going to plenum.

munch munch ls1s for lunch
Best 1/4 mile 13.1@105mph 60ft-1.8sec Reaction time .8 sec 0/100-4.8sec

[VS 355 UTEParticipant QLD96 vs v8 ute View build HERE Member since: January 13, 2016 Posts: 141]

Yeah,not the usual lay out for the IAC but as you said shouldn’t affect how it works.

I,d give it an inspect/clean/lube and see if it makes any difference.When running cams with more overlap,the plenum can become coated in a gummy residue due to fuel drying out after  reversion.Can find it’s way into the IAC over time.

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