DOHC KA has slight misfire(?)/sputters... but not the usual culprits?

[mrgreeneyes]

My ka runs fine for the most part except for more often in warmer weather, when trying to idle it will misfire/sputter. I have a new 300zx TT fuel filter, new spark plugs/wires/dizzy/rotor, timing set to 20*, etc.

It has been auto->5spd swapped, but is running a 5spd ecu. It idles at 1100ish rpm (sucks) but on rare occasions, it will idle at 650 rpm like butter after driving the car around for a little.

I tried searching around, but got no definitive results. Could this be a vacuum prob? fuel prob? Reason I ask about those is that the electrical end is all new stuff.

NICO, help please.

[edgartheace]

I would check my IACV for excessive carbon deposits or sticking, along with your PAIR valve.

[slyedog240sx]

run a little seafoam through the booster line and see if that helps.

[mrgreeneyes]

pair is deleted. iacv would cause a sputter/misfire?

[Soravia]

Mine acts the same. I don't think it's the IACV since all it does is control the same way throttle does.

I'm going to do an oil change later and check the valve lifters. It has something to do with temp. Not the coolent temp but engine bay temp.

What is the last action you did in your engine bay before that happened? i did too many things in my to trace back.
Modified by Soravia at 11:08 PM 8/30/2007

[boriquaS13]

Definately check for vacuum leaks, also check your tps, and your maf sensor.

[mrgreeneyes]

anyone else? I went to demonstrate this to WhiteComet and LegacyOfPheonix last night... and it ran smooth as butter. failed demo.

anyone else have any ideas?

soravia... nothing has changed under the hood in over 5 months.

[Chukidori]

Mine does the same thing...

It got REAAAL bad tonight when i was at the drivethrough, it was mis firing and sputtering so bad i feared engine damage.....but it stopped doing it so bad once i drove it down the road , it will also do it some under driving i can feel the car "tug...tug ..tug tug"

iassumed it was my plug wires since they are ORANGE inside.

[Soravia]

I'm getting the same idea. It MAY BE the plug wires. The engine acts up only when there's hot weather and hot engine.Not when the coolent temp is in the mid. Not when the engine is cold start. I drove back from Wal-mart just now in cool weather after the rain, no sputter. Last night there was sputter after some driving.

Maybe spark plug wire connections are expanding under heat and losing contact?

[mrgreeneyes]

thats very outside the box thinking... but i guess its possible.

but with brand new wires? and i haven't had a prob since i last posted.... and it did the same thing with the new wires that i intentionally flared the ends to for best contact when i installed them... with di-electric gel....

hopefully that was it... thanks everyone...

[deuceforty]

650 seems low for a ka24de... mine idles at 800, 1100 when i have the AC on

[White Comet]

yeah the demo was failed, and no 650 didnt really seem low at all. it just held there perfect and sounded great. the only thing i could think of is maybe the lower trans harness like you mentioned besides that

[mrgreeneyes]

ha, i gotta hurry and order my new clutch then... get that pink camo trans in with a harness

[White Comet]

can't wait for that and i'll be interested to see if that makes a differnce or changes anything