engine randomly dying while driving. HELP!!

[dkim1985]

So last night I was driving home from the movie theatre..and my idle starts fluctuating. then eventually dies AS I'm driving. even when I'm stepping on the gas it was hesitating and then just died.
I had to start it back up in the middle of an intersection and eventually made it home. Not sure what was wrong.

I have a stock KA24DE, with just an exhaust.
Cleaned MAF, New O2 sensor, injectors have even Ohms, new fuel filter, new fuel pump..
s13, with only 130k miles..

I have an AFC Neo on it but I don't think thats an issue cause its been on there for awhile, no problems. Going to pull it out today anyways.

Any ideas or suggestions I should check??
I need my car for work tomorrow! Please help!

[SofaKingFast]

Have you checked for vacuum leaks, specifically for the IACV?

[duafacia]

TPS sensor. Mine died while driving with a heavy idle dip. Adding power didn't help I had to downshift to keep it fired.


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[dkim1985]

TPS sensor. Mine died while driving with a heavy idle dip. Adding power didn't help I had to downshift to keep it fired.


Posted from Zilvia.net App for Android

Is it easy to replace the TPS?
A little earlier, as I was driving/cruising, it would just start to die and wouldnt fire even when I would step on the gas. any other thoughts??

EDIT:
after doing some research, doesn't look like the TPS would cause the problems im having..
is it possible i can have a short somewhere? how would I test that?

[hOngsterr]

i say its still your maf

[TougeSR20Kid]

i say its still your maf

This... Just cus you cleaned your maf doesnt mean it's good

[dkim1985]

yeahhh.. i had a feeling.. i'll see if I can find someone with a good one.
Thanks guys.

[duafacia]

i say its still your maf

While it idles tap it with a wrench see if it bogs/misses. Does it smell rich when it happens? Like its pouring fuel into the chambers.

[dkim1985]

It's definitely pour fuel because it'll spike back up when it catches.

[GroundPerformance]

If this is a bonestock KA.. Cleaning AIV helps as well.

[dkim1985]

If this is a bonestock KA.. Cleaning AIV helps as well.

I cleaned the throttle. but the IACV wouldn't kill the engine, right?

[dkim1985]

boom. switched the MAF. running good now~
thanks guys!

[dkim1985]

sooo..apparently i still have a bogging issue? the engine will idle fine, though you can feel a slight hesitation.
but when i step on the gas, it seems like it has lost power and just doesn't pick up like it used to.
it only feels this way usually once the engine has warmed up a bit.
definitely smells like it's burning up more fuel.
i dont know if this has to do with anything but..after driving for a little bit, the engine gets really hot. without even opening the hood, i can feel the heat from the engine just standing near the car..as if i was just at the track or something even though i've only been driving for about 10 mins local streets.

im thinking about checking the TPS tonight. any other suggestions?

[dkim1985]

TPS seemed a little low. was at around 0.41v.
I had a new TPS on hand so decided to just switch it out completely.
Set it at 0.45v for the time being. Will probably raise it up a bit more.
FYI, when replacing the TPS, you need to unbolt the Throttle Body so make sure you get a new throttle body mounting gasket.

Engine's running fine now. no bogging, no issues with anything.

I was wondering though.. the FSM says the TPS voltage should be .45v to .55v closed throttle.
From your guys experience, would setting it at .50v be ok?
I know it sounds like a stupid question but at .43-.44v my engine seems to be running ok and im just wondering if setting it at .5v will be giving it too much air..
:hs:

[cotbu]

Set it to factory spec! if, you are not tuned and the car runs fine with slightly higher tps voltage go ahead, as long as the TPS registers the closed signal your fine. If you happen to exceed the wot voltage you may see some problem, in that case lower the tps voltage back down. if you are tuned don't adjust it beyond factory specs or ask you tuner what the tps voltage was when he\she tuned you.

[dkim1985]

Set it to factory spec! if, you are not tuned and the car runs fine with slightly higher tps voltage go ahead, as long as the TPS registers the closed signal your fine. If you happen to exceed the wot voltage you may see some problem, in that case lower the tps voltage back down. if you are tuned don't adjust it beyond factory specs or ask you tuner what the tps voltage was when he\she tuned you.
not tuned, stock.
if my TPS is running at 0.41v..would that cause a high idle?

[cotbu]

No, not necessarily. Follow this, if the tps is at .41v and the throttle is cracked open or the IACV is adjusted incorrectly then yes. Get that? In other words everything has to be in sync or adjusting the wrong thing will make identifying the problem worse. It's why we suggest setting everything to factory specs.

[dkim1985]

No, not necessarily. Follow this, if the tps is at .41v and the throttle is cracked open or the IACV is adjusted incorrectly then yes. Get that? In other words everything has to be in sync or adjusting the wrong thing will make identifying the problem worse. It's why we suggest setting everything to factory specs.
ugh~ looks like more work this weekend~ fun! lol

[steve shadows]

GET RID OF THE AFC NOW...it's crap and it just adds in line resistance to your MAF sensor and hacks up the most important wires and inputs for your ecu.

If you need to be able to tune look into some of the AEM piggy backs or just spring for a real EMS and save yourself the trouble now, especially if you're planning bigger mods later. AFCs + Hot Wire Maf cars usually means all kinds of crap idle, dying bogging issues mostly because the instals are not done properly and the AFC is just crap in general. IMHO of course....:bow: