| Author |
Message |
David Grab
TryHard
SA
T78
Posts: 215
Reg: 01-2008
|
Hey guys my car has a bit of an idle issue since yesterday. Normally the car would idle at 600rpm but now it goes to 550/500 and as low as 400 on steady idle. The car vibrates a little bit like its going to stall but doesnt (mostly exhaust vibrations). The car is an auto TT and i just changed the oil over a few days before (Motul Turbo light W10- 40). Anyway normally the car would go to about 1600rpm upon starting on a cold morning and a second later would be declining rapidly to about 1000rpm. Now with the idle problem upon start up in the morning it goes to about 1000rpm and sits at 600 after about 30secs but once warmed up it will go to 400rpm idle. Anyone got any ideas as to what the cause may be and possible fixes. Im thinking something with the alternator and/or battery need replacing. Could also be that power steering fluid got on the battery and causing some elctrical short. |
Peter Nitschke
Junk Filterer
South Australia
UZZ30 UZZ31
Posts: 9506
Reg: 11-2004
|
David, it might be worth checking the IAC (Idle Air Control) valve.
http://www.planetsoarer.com/IAC/iac.htm |
Ryan Rankovic
Goo Roo
Victoria
Soarer TT GT-TL
Posts: 1061
Reg: 07-2005
|
thats happened to me a fair bit
ive noticed it happens only just after ive filled up with petrol
im thinking its just •••••• petrol for me as when it runs low and i put more fuel in the car will get better
have you put petrol in just before it started happening? |
Scott Gates
DieHard
SA
TT
Posts: 643
Reg: 03-2007
|
My car has exactly the same problem at the moment.
But mine actually does stall.
Still yet to figure it out. |
Scott Gates
DieHard
SA
TT
Posts: 645
Reg: 03-2007
|
I changed over the idle control valve today, and still same problem.
I don't have any leaks so mine wouldn't be leaking fluid to short anything out.
But i'm starting to think it may be alternator issue. |
Peter Nitschke
Junk Filterer
South Australia
UZZ30 UZZ31
Posts: 9511
Reg: 11-2004
|
Guys, thinking out loud, the alternator simply charges the battery, the battery runs the car.
So if the battery has enough grunt to start the car, it should have enough to keep it running.
If the battery goes flat from the alternator not charging it, then the car won't start next time, but in your case it does.
I don't see how a dodgy battery/alternator would cause low idle. |
Scott Gates
DieHard
SA
TT
Posts: 647
Reg: 03-2007
|
It really only just starts.
When it starts and i rev the engine to 1000RPM it goes to normal 14V
As of today i have had the charging malfunction error come up. And then you see the power gets low and idle is low and stalls.
Then it will start again, but just do the same thing.
I thought the same thing before Peter, that's why i didn't think the battery/alternator was the problem as otherwise it wouldn't start again.
So i don't know.... still thinking alternator. |
David Grab
TryHard
SA
T78
Posts: 220
Reg: 01-2008
|
Fuel wise ive got about 1/4 of a tank of BP ultimate and wanted to get it as empty as possible before filling up. Normally i fill up each week but the last few weeks each time i fill up ive got more than half a tank. So this week wanted a full tanks of fresh juice. So in theory it could be stale fuel, im about to fill up on Shell fuel so ill see how we go.
Also the voltage is fluctuating so when the revs drop to 400 the front lights emit slightly less light thats why i was thinking something electrical. |
Peter Nitschke
Junk Filterer
South Australia
UZZ30 UZZ31
Posts: 9512
Reg: 11-2004
|
Scott, OK, how about this then?
What if the battery is a bit stuffed? It only just has enough power to start the car, and when idle drops to the point that the alternator isn't really doing much, then the battery can't keep the car alive, so it stalls. After a brief rest, it recovers just enough to start again.
When the engine is revving, the alternator has enough speed to supply the volts/current that the engine needs.
Tried a different battery? |
Peter Nitschke
Junk Filterer
South Australia
UZZ30 UZZ31
Posts: 9513
Reg: 11-2004
|
David, revs dropping and lights going dim is normal as the alternator isn't going fast enough to keep things fully charged. |
Scott Gates
DieHard
SA
TT
Posts: 648
Reg: 03-2007
|
Peter, that makes sense.
I'm going to get the RAA to come check it tomorrow, and i'll see if it's the battery.
So if the battery is weak it could cause it to idle low.
David, i tried different fuel also, had no effect. |
Peter Nitschke
Junk Filterer
South Australia
UZZ30 UZZ31
Posts: 9514
Reg: 11-2004
|
Scott, I still don't see why it would idle low however. It should either run or die, but there could be things happening that I don't know about, eg sensors or ECU might go a tad odd if the voltage drops.
Any chance you guys use the same service station?  |
Scott Gates
DieHard
SA
TT
Posts: 649
Reg: 03-2007
|
I'm pretty sure David lives up north. So a fair way just for petrol.
Also i have filled up with different fuel since the problem started. So it can't be a fuel issue for me. |
David Grab
TryHard
SA
T78
Posts: 225
Reg: 01-2008
|
I use the BP at Prospect and also my work Premium at Liberty (rebadged BP ultimate). Thinking i might see how i go with V-power for a full tank and see the economy.
Also the story behind powersteering fluid on the battery. Paid $200 for my leaking powersteering pump to be fixed but the guy didnt fix anything. When to a motorkhana and from turning around at speed some fluid leaked out from what looks to be the top of the reservoir and onto the top of the battery. Now im not too sure if their is air in the system or if the powersteering pump if finally on its last legs but at low speed (less than 5km/hr) or from a dead stop the steering is the same as a car with no powersteering in it. Ive fileld up the reservoir to full and it doesnt occur too often now but ill be bleeding the system and see if that helps. So the powersteering fluid potentially linked the to terminals and shorted the battery. Thats one of my many theory anyway haha. |
Peter Nitschke
Junk Filterer
South Australia
UZZ30 UZZ31
Posts: 9518
Reg: 11-2004
|
Have you cleaned the PS fluid off the battery? |
David Grab
TryHard
SA
T78
Posts: 226
Reg: 01-2008
|
Yeah of course that was the first thing i did. |
David Grab
TryHard
SA
T78
Posts: 229
Reg: 01-2008
|
Looks to be sorted with some fresh BP ultimate :-) |
Gary Poloskei
Tinkerer
A.C.T
Soarer TT
Posts: 39
Reg: 01-2008
|
just a side note:
Peter you mentioned that the battery runs the car?
This must be a soarer thing. coz every other car iv owned I call pull the battery out of the car while it's running and it will continue to run. in fact you can replace the battery with a flat one if you want to charge it!
Someone clear this up for me please coz it's real weird. |
Gary Poloskei
Tinkerer
A.C.T
Soarer TT
Posts: 40
Reg: 01-2008
|
And to the people having this problem I suggest you replace your fuel filter.
$135 geniune. |
Peter Nitschke
Junk Filterer
South Australia
UZZ30 UZZ31
Posts: 9524
Reg: 11-2004
|
Gary, it will if the battery is removed, but likewise the car will run without an alternator - at least until the battery goes flat. |
David Grab
TryHard
SA
T78
Posts: 230
Reg: 01-2008
|
Yeah Gary potentially it could be the fuel filter however so many people having the same issue would be highly unlikely. Im putting my idle issue down to stale fuel even though it was old so even a bad batch possibly. Ill let you guys know if it comes back when i get back to around the same level of fuel i had when the problem was occuring. |
Gary Poloskei
Tinkerer
A.C.T
Soarer TT
Posts: 41
Reg: 01-2008
|
how long does fuel take to got stale? |
Scott Gates
DieHard
SA
TT
Posts: 650
Reg: 03-2007
|
Ok i had the RAA come to check it out yesterday.
The guy said it is the regulator on the alternator, as the volts were all over the place.
Any good auto-electricians in SA people would recommend? |
David Grab
TryHard
SA
T78
Posts: 231
Reg: 01-2008
|
Fuel usually goes bad after 5-6 weeks after getting it from a servo, well its still usuable to a decrease but after this time period the octane rating will have started to decrease. So mine probably wasnt stale as its my daily and the fuel was around a week or week and a half old. Probably just a poor batch from the refinery.
Hey Scott does the RAA come out for free to do those check when your a member or does it cost you something? |
David Tra
Tinkerer
qld
TT
Posts: 75
Reg: 11-2007
|
David Grab wrote on Monday, June 09, 2008 - 08:42 pm:Anyway normally the car would go to about 1600rpm upon starting on a cold morning
is this normal as sometimes mine revs up to 2k rpm |
Scott Gates
DieHard
SA
TT
Posts: 719
Reg: 03-2007
|
Ahh for F*** sake, today i changed over my alternator and guess what still have the same issue. Car starts and after a little while the idle goes really low around 400rpm then stalls....
Ok guys i'm really stumped now.
Parts i have checked/replaced or tested with other parts on working cars:
ISCV
Fuel filter
Coil packs
Spark plugs
Battery
Alternator
Fuel pump ecu
Reset ecu
Changed over fuel
Any thing else i can try??
Or should just give in and attempt to get it down to mechanic. |
Brian Kelly
TryHard
Colorado USA
SC300 5-speed
Posts: 323
Reg: 04-2007
|
I have the same problem on the 1j i just put in. Could spark plugs be the problem? |
Scott Casey
Tinkerer
nsw
soarer v8
Posts: 85
Reg: 02-2008
|
ign leads, check the ohms with a multimeter
check all the earths
do you have an alarm (incorrect wiring, dodgy connection)
aftermarket sub amp
$100 ebay voltage stabilizer
some more suggestions |
Damian Ware
DieHard
Victoria
UZZ32
Posts: 711
Reg: 10-2005
|
I would check the TPS.
Then try another ECU. |
Scott Gates
DieHard
SA
TT
Posts: 740
Reg: 03-2007
|
If i adjust the idle higher by putting a nut on the idle screw, and raise it to around 700rpm which was my normal before, it works fine.
So it has to be something linked with the idle setting.
Brian, it is not spark plugs as i changed them to new ones to be sure.
Scott, i do have an alarm, and i installed it so i know its schmick. lol Also disconnected my stereo system for the time being.
Will test other parts today.
Damian, I thought of the TPS the other day, but never got around to testing it. But its a good idea to give it a test. |
Scott Gates
DieHard
SA
TT
Posts: 774
Reg: 03-2007
|
 Finally found the problem yesterday arvo.
It ended up to be a pinched hose.........
At least now i know EVERYTHING else is working great.
Well it gave me more experience in taking my car apart and testing stuff, rather than depending on a mechanic and emptying my wallet. |
Peter Nitschke
Junk Filterer
South Australia
UZZ30 UZZ31
Posts: 9676
Reg: 11-2004
|
Which hose? |
Brian Kelly
TryHard
Colorado USA
SC300 5-speed
Posts: 324
Reg: 04-2007
|
I found the problem to be a hose too. For me it was one of the ones off the bypass valve. Someone had Tee'd off a hose for a boost guage and I had blocked off the nipple for the hose. When I took off the tape covering the hole, it began sucking in air and idle'd really high. (1700rpm). I ended up putting some heat shrink on it, and shrinking the end until it idled at around 700. |
Scott Gates
DieHard
SA
TT
Posts: 780
Reg: 03-2007
|
Yeah mine was a vacuum hose of sorts.
Just replaced the hose and bam perfect. |
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