What could cause fast idle?

[Anonymous]

Hi all. Couple of noob questions about my 99 mrs.

Warm, it idles at 1500 rpm. But the temp gauge won't get to half way, normally about 1/3 ish. Fan works fine. Hot air from heaters so not thermostat.

Only mods are a stainless jap system and an air filter/cold air feed thing. (not done by me).

Idle control valve? Maf? O2 sensor?

[Anonymous]

Try cleaning the MAF,instructions are in my signature.

[Anonymous]

Ta  s:) s:)  I'll grab some carb cleaner then  s:) s:)

[ChrisGB]

Thermostat stuck open perhaps?

Chris

[Anonymous]

Well today i had a tinker. My fuel economy was appalling, 120km for £30 appauling and it smelled rich.

So, maf cleaned. The thermistor was black. It's now an Amber colour and I can see the wire inside. Couldn't before.

New set of plugs in, noticed a weep of oil from the rocker gasket on the coil packs. Not a load, just a residue.

Started her up and she went to 1500 rpm, then dropped to 1100-1000. I think I may have cured something   s:) s:)

[Anonymous]

A video of what it's like now. Normal?
 m http://i124.photobucket.com/albums/p29/ ... c4f8e8.mp4 m
I can't embed it on my phone  s:( s:(

[ChrisGB]

A video of what it's like now. Normal?
 m http://i124.photobucket.com/albums/p29/ ... c4f8e8.mp4 m
I can't embed it on my phone  s:( s:(

Is that fully warmed up? If so, I still have a feeling the thermostat is sticking open.

Chris

[Cap]

But the temp gauge won't get to half way, normally about 1/3 ish. Fan works fine.

I'm with Chris on this..  

I'm a little Confused..  What Fans are you talking about.. the Radiator Fans?...  If so thay are Controlled by the ECU Engine Temp..  and if the  Engine Temp never gets Warm..  then the Radiator Fans should not come on?..  

But I still agree, that Somethings Wrong..  

Cap

[Anonymous]

Yeah that's about as warm as it gets. Idle is now hunting between 1000 and 1500. It's bugging me now. And if I read correctly, there's no way of plugging an mrs in is there?

I've considered the stat, then sensors, timing being advanced, but I'm just guessing.

[ChrisGB]

Yeah that's about as warm as it gets. Idle is now hunting between 1000 and 1500. It's bugging me now. And if I read correctly, there's no way of plugging an mrs in is there?

I've considered the stat, then sensors, timing being advanced, but I'm just guessing.

If the thermostat is stuck open, the engine may never get to full working temperature, so the water temperature sender will be telling the ECU that the engine is not yet warm. Result would be that the engine stays in warm up mode (fast idle and rich mixture) and the temperature gauge does not show fully warm. You also mentioned the rad fan works OK, but if the temperature is not fully up to standard working level, the fan should never come on, unless hot water is getting to the radiator before the engine is fully warm, which it should not. For me, all this points to a thermostat fault as the first thing to eliminate.

Chris

[Anonymous]

Yeah the rad fan came on once, when I'd parked up actually and turnedthe engine off. Where is the stat then?

[Mike_V]

If the thermostat is stuck open, the engine may never get to full working temperature, so the water temperature sender will be telling the ECU that the engine is not yet warm. Result would be that the engine stays in warm up mode (fast idle and rich mixture) and the temperature gauge does not show fully warm. You also mentioned the rad fan works OK, but if the temperature is not fully up to standard working level, the fan should never come on, unless hot water is getting to the radiator before the engine is fully warm, which it should not. For me, all this points to a thermostat fault as the first thing to eliminate.

Chris[/quote]

+1

[Anonymous]

Right then, I'll get a new stat ordered. £12 odd from camskill.

Is there a way of plugging the car in? My engine management light seems to have had it's bulb removed. I could need all sorts of sensors all over the place. Could o2 sensors cause these symptoms?

[Anonymous]

Sure can.    l viewtopic.php?f=47&t=31275&p=381395&hilit=paper+clip#p381395 l

[Anonymous]

That's useful  s:) s:)  I guess I'll be getting a bulb for the cel then. Let's get that can of worms opened.

[Anonymous]

 l viewtopic.php?f=11&t=32466&hilit=+light l

 l viewtopic.php?f=11&t=25259&p=349292&hilit=j+spec+readers#p349292 l

[Anonymous]

Right an update. Thanks to Bryan, I've been eliminating a few things.

I've had the cluster off and the cel is present and looks fine. It doesn't light up, I checked for tape and took it all to bits. Nothing there at all.

I looked at the ecu. All the wires are in tact there too.

So my theory is, whatever is causing the fast running, rich mixture and poor economy also lit the light up, and it either burned out or was disabled. Probably the latter.

So fix the light, find the fault, and fix that. Simples!

So guys, possible causes of my symptoms.

Fast idle, sometimes hunting but only when warmer. Temp reading never at half. Fan not cutting in. Poor economy, smell of rich mixture.

Incidentally, the plugs weren't black or wet when I swapped them. I've ordered a stat and I'll swap
That on Tuesday or Wednesday. What else now?

[Anonymous]

So fix the light, find the fault, and fix that. Simples!
I've ordered a stat and I'll swap
That on Tuesday or Wednesday. What else now?

Stick to your plan,you look like your on the right track.Getting that EML working is the key.

[Anonymous]

Update time  s:) s:)

The fan kicks in here


So it's not the stat, but a new one can't hurt.

So I pulled the clocks apart. Can you see why my cel ain't working yet?


I'll give you a hint


And ta daaa!


I'm off to find a paper clip and report back with whichever sensor/components are broken.

[Anonymous]

Right. Error codes 21 and 28  that's all  s:) s:) .

So is that both oxygen sensors?

[Mike_V]

I assume those codes are PO021 & 28 in which case they are Camshaft Position Actuator A-Bank 2 timing over advanced and Intake Valve-Bank 2 control solenoid CKT range/performance, respectively. I'm sure that someone more learned will be along to explain those codes in more detail.

[Anonymous]

No, mine is a j spec so I'm reading flashes of the engine management light. The two codes that came up were 21 and 28. According to the link that life of bryan posted up, both those codes relate to o2 sensors.

The uk codes are different I think.

[Mike_V]

Dohh. Didn't read that post.   s:oops: :oops: s:oops:

[Anonymous]

No, mine is a j spec so I'm reading flashes of the engine management light. The two codes that came up were 21 and 28. According to the link that life of bryan posted up, both those codes relate to o2 sensors.

The uk codes are different I think.

Sounds like both your manifold sensors,with it be an import you wont have a post cat sensor,see here for sensors to buy:   l viewtopic.php?f=11&t=19412 l

1-Digit   2-Digit   Meaning
1   None   Normal -- no problem
    11   Loss of power to ECU: ignition switch/circuit; main relay/circuit; ECU
6   12   RPM signal/no-signal to ecu from distributor ("ne" or "g") after engine has been cranked: distributor/circuit; starter/signal circuit; igniter/igniter circuit; ECU
    13   Same as 12 but after engine has run at 1,000-1,500 rpm: distributor/distributor circuit; ECU
3   14   Ignition signal (no "igf" signal to ecu, no signal from igniter 4 times in a row): igniter/igniter circuit; igniter and ignition coil/circuit; ECU
5   21   Oxygen Sensor signal/oxygen sensor heater signal: open/short in oxygen sensor or signal
4   22   Water temperature sensor signal (open or short in water temperature sensor signal): water temperature sensor circuit; water temperature sensor; fault in coolant temperature sensor circuit; ECU
8   24   Intake air temperature sensor signal: open or short in intake air temperature signal; intake air temperature circuit; intake air temperature sensor; ECU
    25   Air/fuel ratio lean indicator (lean signal sent to ECU from oxygen sensor): injector fault(s); injector circuit; injector; oxygen sensor circuit; oxygen sensor; air leak; fuel pressure line; airflow meter or map sensor; ECU. Try cleaning the injectors.
    26   Air/fuel ratio rich indicator: same as 25; cold start injector
    27   Sub-oxygen sensor circuit or sub-oxygen sensor heater circuit; ECU
    28   #2 oxygen sensor/oxygen sensor heater; same as code 21
2   31   Manifold and/or airflow meter sensor signal circuit: airflow meter/circuit; manifold pressure sensor/circuit; ECU
    32   Airflow meter signal (vane-type): airflow meter/circuit; ECU
14   34   Abnormal turbocharger pressure: turbo charger; airflow meter/manifold/turbocharger pressure sensor; intercooler system; ECU
    35   Turbocharger pressure sensor signal: turbocharger pressure sensor; ECU
7   41   Throttle position sensor signal: open or short in tps signal; tps sensor; tps signal/circuit; ECU
9   42   Vehicle speed sensor signal circuit (no speed signal for several seconds): while vehicle is operated under heavy load (tps/map/air flow inputs); speed sensor/circuit; ECU
10   43   Starter signal (no "sta" signal to ecu until engine speed exceeds 800rpm): vehicle is push started; ignition switch/circuit; ECU. Not a real problem unless it recurs.
11   51   Switch signals: TPS idle switch off; neutral start switch off (automatic transmission in Drive); A/C switch on; A/C switch/circuit; A/C amplifier; TPS/circuit; neutral start switch/circuit; ECU
12   52   Knock sensor signal (open or short in knock sensor signal): knock sensor/circuit; ECU
13   53   Knock control signal in ECU
    71   EGR valve malfunction (exhaust gas tempeature below specification for EGR control): EGR system; EGR gas temperature sensor/circuit
    72   Air conditioner compressor relay/relay signal: A/C compressor relay/circuit; ECU

[Anonymous]

Brilliant. Having two knackered sensors, would that cause the symptoms I have then?