RB20 idle problem

[Nic_A31]

hey dudes, check this.

hard to start, especially cold.
idles at 1500 to 2000 rpm until warm up.
sometimes will drop down to 1000 or so once warm, otherwise need to be adjusted.
despite adjust, and warm start straight after being turned off, again idles at 1500 to 2000 rpm until adjusted.
Intermittent miss at idle and becomes much worse once throttle opens.

ideas??

reset computer, replaced AFM, adjusted ignition timing, to no avail.

[magic1]

have you got a wolf?

i really have no idea

[evoeata]

do they run an IACV like sr's? inside the intake manifold. my old sr would do this, took it out and cleaned it. problem solvered.

[Jiblet]

do they run an IACV like sr's? inside the intake manifold. my old sr would do this, took it out and cleaned it. problem solvered.

^this

[DCEVO]

I have bits you can swap out to eliminate if need be:)

[zeroyon]

As said the IACV is either stuck or the sensor that tells it to stay open is failing.

So if cleaning out the IACV doesnt work or changing it, then change the water temp sensor(the ecu one, not the dash one).

[zeroyon]

Or you could have a big air leak also :)

[Nic_A31]

Havent checked IACV yet, didnt even occur to me.

I do have an exhaust leak, possibly two, before the O2 sensor (one at port/manifold and another possibly at manifold/turbo) but definately no intake leaks.

[Nic_A31]

I gave the IACV a very quick clean, and I emphasize, very quick, ie very half-assed to see if it atleast improved (in which I would re-remove it and clean it properly) and it runs WORSE.

Now will not start at all with AFM connected and if it does, idles at 2300 rpm, miss/backfire has become more frequent, thats if it starts at all.

Again. Any idea's are welcome.

[Nic_A31]

I'm ringing Bart tomorrow - unless someone on here wants to have a crack at it for me?
Carton of piss in it for whoever works it out.

[d1kiwi]

dunno if this helps at all but 4 the idle issue u have it sounds very famlier, was a 20det and we traced the fault 2 the idle control motor, found out out a cheat way of checking was 2 clamp pliers on the vac hose runnin 2 tha unit and tha idle changed instantly, we used a line locker on there az a tempary solution until the unit was replaced.
like i said may help the idle issue then u kn find tha missing problem, post up what the problem actually is if u find out coz my 20det is getting hard to start in the mornings and misses until warm alltho my coils are screwed, cheers

[Nic_A31]

Solved.

ECU water temp sensor by the looks of it.
Can run and rev out with AFM connected but no water temp sensor, but have to keep revs up myself. Revs fine.
Water temp sensor connected, no AFM, idles stupidly high, revs like shit.

Couldn't run with both due to conflict of AFM and water temp signal.

[DISTRBD]

So if cleaning out the IACV doesnt work or changing it, then change the water temp sensor(the ecu one, not the dash one).


Again. Any idea's are welcome.


Solved.
ECU water temp sensor by the looks of it.



Did you miss Simons post about sensor ?

[Nic_A31]

Would seem I did indeed.

[Nic_A31]

We both spoke too soon.

Replaced water temp sensor, $87 later, problem persists.

I've been told to isolate the problem before I cry out "warranty" (go figure), so yet again, if you got idea's, throw them at me.

Now hates to rev out with AFM connected.
OK with either ~10% throttle or full throttle, anywhere in between it will misfire badly and go stupid, vacuum returns to zero, it cuts fuel and spark until throttle is closed again.

I need this car running ASAP :\

[DISTRBD]

I've been told to isolate the problem before I cry out "warranty" (go figure), so yet again, if you got idea's, throw them at me.



Is this the same car you fitted 25de into and fried ecu due to incorrect wire up ?

Possible there is another issue from that little fuck up ?

[Nic_A31]

20DET is a straight plug in and everything is working fine.
I ripped everything out from dash to firewall and checked it, the whole lot.

Car was running fine and problem slowly got worse and worse.

BTW where's my receipt? and panels?

[Mad_Aussie]

Vaccum leak?

[DISTRBD]

20DET is a straight plug in and everything is working fine.
I ripped everything out from dash to firewall and checked it, the whole lot.

Car was running fine and problem slowly got worse and worse.

BTW where's my receipt? and panels?

You had the complete wiring harness out from car ?

Panels here waiting for next perth run , reciept you never asked for .

send details info@swbrakes.com.au

Just get the workshop who did install to call me direct , be alot easier

[Nic_A31]

You had the complete wiring harness out from car ?

Panels here waiting for next perth run , reciept you never asked for .

send details info@swbrakes.com.au

Just get the workshop who did install to call me direct , be alot easier

Like I said on the phone, I disconnected the ECU and pulled wiring harness through firewall, lifted motor out, dropped it into car, put harness back through Cefiro firewall, connected ECU, dash plugs also connected straight in with no modifications, done. If you're referring to the body loom, yesI'd removed those as well when I tested everything.
The 25 wiring issue killed ignition switch and one fuse, that's it.

Now I'm asking for a receipt.

[kurbn]

If I was in your shoes
- Check every pipe join on your Intercooler setup
- Have you had your injector rail out at all?
- Spray some throttle body cleaner around your inlet manifold/injector rail to see if the idle picks up
- Are you running a catch can? If so make sure you blocked off the Inlet manifold properly if you're running a breather and make sure the metal pipe from the inlet hose is also blocked off.
- Check Inlet hose to compressor housing fitment/for leaks

Sounds to me like a vac leak

Check all the stupid shit.. I spent 3 days chasing an issue like this...an intercooler pipe that I neglected to tighten a hose clamp up on which allowed the pipe to slip out enough to breath but not enough to stand right out.

[supra_jza70]

check every vac hose, use carby cleaner while its running
find a spot where it gains revs and check the area thoroughly
as bangn said....
if nothing
make sure all the hoses are where they are supposed to go.
and check all electrical connections

[Nic_A31]

I'm positive about intercooler pipes as I've checked those 3 times now, and tightened them down with hardcore clamps.
I removed the intercooler - > crossover pipe, connected AFM straight to crossover pipe and pod onto that completely cut out the turbo. Same problem.

Connected up my boost gauge to a small line that runs to the canister. With the throttle body closed and the intake relying on the IACV (which is 2-3 seconds before it fails to idle) boost gauge reads 20 IN-HG, whenever the throttle body is open (even slightly) all vacuum returns to zero. Guess that narrows it to a leak somewhere on the intake manifold.

It fails to start with no TPS connected. Is that normal? I always thought they could start without a TPS...

Next question, possibly not related. Exhaust temps are a hotter going by feel. Related to intake leak or exhaust leak before O2, or both ? I'm guessing intake leak affecting fuel pressure reg ?

[DISTRBD]

definately no intake leaks.


I'm guessing intake leak affecting fuel pressure reg ?


:confused:

[Nic_A31]

OK so maybe all the oil pissing out the intake side camshaft seal made a meal of the intake manifold gasket. Good condish motor right there.

Anything before the throttle body, throttle body itself and IACV is definately all good, no leaks. If it's behind that, fuck know's.

[dose_it]

Nic you have no luck. Sell cefiros buy an excel :)

[kurbn]

Did you spray anything around the intake manifold?

[Nic_A31]

Yeah and tried the lighter trick. 4, 5 and 6 all good, bit harder at the front cos of the fan. Oil leak on the cam seal was right over 1 & 2.

[_oz]

checked base timing ?

have you tried actually replacing the iacv unit instead of just cleaning it?

tried another afm ?

checked for any damage to the wiring loom?