Peter Gidden - SBITS wrote:OP.
Has ignition timing been reset correctly?
Are cams dialled in correctly?
Yes, I have been assured ignition timing and cams are set up as per Hks datasheet, and Toyota manual.
Idle problem
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Re: Idle problem
Yes, I have been assured ignition timing and cams are set up as per Hks datasheet, and Toyota manual.
Re: Idle problem
dan4 wrote:Op also made it appear as if the engine was built to that spec before refitting?
Engine was standard, and working fine.
Was then removed and rebuilt as per mentioned spec in original post.
Re: Idle problem
ashley wrote:Nothing in there to suggest that he's changed his ISC spring
Actually- you know what? I bet he made the mistake of replacing it with a denso spring instead of getting a genuine toyota one, that would explain everything.
ISC has not been changed or touched during the rebuild.
And if anything has been replaced of this nature it has always been with original Toyota parts.
You buy cheap you buy twice (usually in past experience).Re: Idle problem
GTMatt wrote:dan4 wrote:Op also made it appear as if the engine was built to that spec before refitting?
Engine was standard, and working fine.
Was then removed and rebuilt as per mentioned spec in original post.
Exactly as I thought before the usual bum bretheren's began to comment.
The airflow characteristics have changed slightly, it could well be idle control. Or fuelling, anything changed on fuellingRe: Idle problem
dan4 wrote:The airflow characteristics have changed slightly, it could well be idle control.
Which will have absolutely no effect on the ISCV calibration whatsoever
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This could take a while.
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Last edited by ashley on Sat Apr 13, 2013 8:54 am, edited 1 time in total.
Re: Idle problem
GTMatt wrote:Mechanic ensured me the isc valve was removed cleaned and is functional.
Might be worth checking that he didn't inadvertently adjust the iscv spring when he did this
Re: Idle problem
The TPS tells the ECU to go into closed loop mode and adjust the fuel from the feedback from the O2 sensor. As soon as you open the throttle quite a small amount the ECU will go into open loop and run off the map in the ECU
There is a make and break switch in the TPS that turns closed loop on and off
This is not easy to set up, takes some time with feeler gauges, but it has to be right
The ECU adjusts the ISC to give the correct air to match the fuel and give an idle of 900 rpm when the engine is hot.
When the engine is cold the idle speed will be higher but not too much.
Check the engine temp sensor, it may be telling the ECU the engine is cold all the time and putting in too much fuel.
This is not the same sensor as used for the gauge in the car
As soon as you open the throttle quite a small amount the ECU will go into open loop and run off the map in the ECUThere is a make and break switch in the TPS that turns closed loop on and off
This is not easy to set up, takes some time with feeler gauges, but it has to be right
The ECU adjusts the ISC to give the correct air to match the fuel and give an idle of 900 rpm when the engine is hot.
When the engine is cold the idle speed will be higher but not too much.
Check the engine temp sensor, it may be telling the ECU the engine is cold all the time and putting in too much fuel.
This is not the same sensor as used for the gauge in the car
Designer for turbo set ups on F1 cars, and Nitrous Oxide Systems of the USA in the 80s