bad idle - new parts galore :( need advise please help

[aussieghostrider]

Can someone please tell me what would cause the car to idle really low that it stumbles to chase revs when sitting in traffic lights ? if I put in neutral its fine .. and may skip a little. It's a Vn V6 1990 executive series 1 with auto transmission.

the car on cold start is perfect but once it warms up and sitting in traffic lights the idle goes from good then gets lower and lower then almost stalls but skips back , the tensioner arm jumps up and down and theres a vibration.The car accelerates good so the only problems when at lights for a long period ...

I said I was gonna chuck the car a year or so ago but no I keep it and look what I get ..

Cars original owner .. oil changes every 5000km ... has around 220,000 on it .. all original engine , trans , diff ...

I have replaced ..

fuelpump , cas , coilpack+dfi , spark plugs and leads , gave the throttle body a good spray with carby cleaner , new waterpump , new thermostat , new battery , ran injector cleaner , fuel filter . new radiator , new balancer... oxygen sensor ..all in the last 2 years...

I was told by 2 mechanics it's inlet manifold but then others said no its not ... I don't know what to do .. I can throw it into Neutral at lights to avoid it but my mum drives the car and she wont like having to do that..

when my battery died and needed a jumpstart , my mates dad checked the voltage and said something to me about alternator putting out too much power and would be bad for battery so could that have anything to do with it ?

WTF do I have to do ???? inlet manifold , IAC , TPS , coolant temp sensor .. ????? I have no idea on checking error codes .. I know how to change sparkies and oil .. coolant ..basic stuff ...

 

[D3V14NT]

Theres another thread on here that gives you instructions on how to check for error codes with some pictures and what not. Should be easy enough to find with a quick search.

You'll want to check those codes before doing anything else though as it will hopefully tell you right away whats causing the troubles.

Personally though I'd change the coolant temp sensor and re do the inlet manifold gaskets just for piece of mind. They are easy enough to do if you're capable of using a spanner. Get yourself a manual just to be sure.

 

[aussieghostrider]

ok I was just driving and the lights dimmed a little as its happening ..

The alternator is like 5 or more years old ... and when I had battery replaced I was told the alternator was putting out more volts than it should so if alternators on its way out thenthat would cause power fluctuations and bad idle especially when its warm ... anyone think this might be it ?

 

[Dum*P*ster]

Hi mate, check your Coilpacks wires..And have a squizz at the Battery terminals, they might be to shity.. And ya might need new ones.

Here is a quick n' easy test to see if your alternator is ok.

1 - Losen the + (POSITIVE) Battery terminal , but enough for the car to start up.
2 - Once the car is running, take the + terminal OFF the battery (DONT let it touch ANY metal in the car)
3- If the car is still running with the + terminal off, your alternator is fine. *IF* the car stalls, then the alternator is not able to keep the car running

 

[Cheap6]

Here is a quick n' easy test to see if your alternator is ok.

1 - Losen the + (POSITIVE) Battery terminal , but enough for the car to start up.
2 - Once the car is running, take the + terminal OFF the battery (DONT let it touch ANY metal in the car)
3- If the car is still running with the + terminal off, your alternator is fine. *IF* the car stalls, then the alternator is not able to keep the car running

Sorry, but that's a great way to create a voltage spike that can damage the ECM +/or alternator voltage reg. diodes. Better to spend ~$15 on a multimeter. The voltage across the battery should be ~12.6V engine off, ~13.8V at idle => ~14.2V (and no higher) with the engine revs lifted.

Maybe try a better shot at cleaning the throttle body and IAC valve; you can't really do a good job of that without removing the TB and separating the IAC valve from it. Carb. clean isn't the best thing to use either as it tends to wash the lube out of the IAC gears and TB spindle. Use a kerosene soaked rag instead. Pay special attention to cleaning the edges of the throttle plate, the TB bore and the IAC valve port and pintle (end of the valve). The grease on the valve gears can dry out too. A squirt of Lithium spray grease might help that.

A quick, rough, check of the IAC valve operation is to remove the intake air duct (elbow) and block the port in the TB to it with a finger (or partially block - the engine may stall with it completely blocked). The ECM will open the IAC valve to correct the idle speed and when you unblock the port the engine speed should flare before dropping back to normal.

The IAC valve gears shouldn't have a great deal of play in them either.

If that doesn't help, look for loose, broken or split vacuum hoses. A leaking inlet manifold gasket should be pretty consistent in it's effect on the engine.

Also look for loose electrical connectors, including the battery terminals.

 

[vp_commo]

ok I was just driving and the lights dimmed a little as its happening ..

The alternator is like 5 or more years old ... and when I had battery replaced I was told the alternator was putting out more volts than it should so if alternators on its way out thenthat would cause power fluctuations and bad idle especially when its warm ... anyone think this might be it ?

that sounds like a common alternator/regulator (same unit) issue, as stated above check the volts when the engine is running, they should be 14 or over.

Cheers
Dan

 

[aussieghostrider]

Ok I went to a mechanic who repalced coil pack and he said the the idler arm spring is stuffed and its causing that vibration and bad idle ... told me to spray heap of wd 40 in and around it to clean it out ..

seems to have helped ....

he told me $80 in labour and then whatever it costs for the part , he said he could get but he told me to have look at ebay and get the part for as cheap as I can.

can anyone tell me where I can get a new tensioner arm assembly for a vn v6 series 1 ??

I looked on ebay stil not found anything ... I want a new one .. not one from the wreckers ... I found one thats for a vs v6 $176 <-- a vs idler arm would fit the vn ok??

can anyone help me locate this part at a fair price ?

 

[wildss]

bursons, repco, r&e autos or a holden dealer

 

[Dum*P*ster]

Sorry, but that's a great way to create a voltage spike that can damage the ECM +/or alternator voltage reg. diodes. Better to spend ~$15 on a multimeter. The voltage across the battery should be ~12.6V engine off, ~13.8V at idle => ~14.2V (and no higher) with the engine revs lifted.

Maybe try a better shot at cleaning the throttle body and IAC valve; you can't really do a good job of that without removing the TB and separating the IAC valve from it. Carb. clean isn't the best thing to use either as it tends to wash the lube out of the IAC gears and TB spindle. Use a kerosene soaked rag instead. Pay special attention to cleaning the edges of the throttle plate, the TB bore and the IAC valve port and pintle (end of the valve). The grease on the valve gears can dry out too. A squirt of Lithium spray grease might help that.

A quick, rough, check of the IAC valve operation is to remove the intake air duct (elbow) and block the port in the TB to it with a finger (or partially block - the engine may stall with it completely blocked). The ECM will open the IAC valve to correct the idle speed and when you unblock the port the engine speed should flare before dropping back to normal.

The IAC valve gears shouldn't have a great deal of play in them either.

If that doesn't help, look for loose, broken or split vacuum hoses. A leaking inlet manifold gasket should be pretty consistent in it's effect on the engine.

Also look for loose electrical connectors, including the battery terminals.

LOL didint no that!

thanks