Could anyone advise please, I have recently had my rev 3 turbo engine rebuilt, it is still with the garage as have reached the last hurdle of starting it up and it won't self sustain itself on idle (aka no throttle input and it stalls).
Engine has got Hks 264 cams
86.5mm cp pistons
Eagle rods
All bearings and studs replaced by the usuals (arp etc)
Currently running with standard fuelling, ecu and turbo.
Runs very smoothly when any throttle is engaged, even just holding the throttle to run it at 850-1000 rpm and it runs fine, but as soon as you let off the throttle it will stall.
Cam and ignition timing is set as it should be, injector seals have been replaced as believed it was a leak from around that area, all pipes have been checked and checked again, and no engine error codes being displayed when you perform the diagnostics trouble code procedure.
Can anyone suggest anything/ experienced something similar?
Cheers
Matt
Idle problem
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Re: Idle problem
Check operation of ISC.
Re: Idle problem
That will be next on the check list then. Hopefully will report back with good news.
Thanks
Thanks
Re: Idle problem
Mechanic ensured me the isc valve was removed cleaned and is functional.
I forgot to mention in the original post it has a fidanza lightened flywheel, would the reduced inertia from a lighter flywheel be the cause of it stalling perhaps?
I forgot to mention in the original post it has a fidanza lightened flywheel, would the reduced inertia from a lighter flywheel be the cause of it stalling perhaps?
Re: Idle problem
GTMatt wrote:Mechanic ensured me the isc valve was removed cleaned and is functional.
I forgot to mention in the original post it has a fidanza lightened flywheel, would the reduced inertia from a lighter flywheel be the cause of it stalling perhaps?
No
If the isc is working ok it must be the o2 sensor if the TPS is working and set up
Designer for turbo set ups on F1 cars, and Nitrous Oxide Systems of the USA in the 80s
Re: Idle problem
You could try adjusting the idle control valve to attempt to bring up the idle speed
Re: Idle problem
bobhatton wrote:GTMatt wrote:Mechanic ensured me the isc valve was removed cleaned and is functional.
I forgot to mention in the original post it has a fidanza lightened flywheel, would the reduced inertia from a lighter flywheel be the cause of it stalling perhaps?
No
If the isc is working ok it must be the o2 sensor if the TPS is working and set up
I advised him to reset the TPS just to make sure. And will try to get my hands on an O2 sensor asap. To be so close yet so far is killing me!
Re: Idle problem
dan4 wrote:You could try adjusting the idle control valve to attempt to bring up the idle speed
That is what the ECU does
Designer for turbo set ups on F1 cars, and Nitrous Oxide Systems of the USA in the 80s
Re: Idle problem
bobhatton wrote:dan4 wrote:You could try adjusting the idle control valve to attempt to bring up the idle speed
That is what the ECU does
To a point, there is also adjustment on the idle control valve
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Re: Idle problem
I've never had an ECU not control idle on a properly working engine.
Toyota make no mention of ISC adjustment either:
Toyota make no mention of ISC adjustment either:
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Re: Idle problem
OP.
Has ignition timing been reset correctly?
Are cams dialled in correctly?
Has ignition timing been reset correctly?
Are cams dialled in correctly?
Re: Idle problem
They dont specify adjustment in the workshop manual however there is an end stop adjustment and adjustment of the bimetallic spring placement. Dropped my cold idle speed to 1400 from 2000. Still specialists know best....
Re: Idle problem
dan4 wrote:They dont specify adjustment in the workshop manual however there is an end stop adjustment and adjustment of the bimetallic spring placement. Dropped my cold idle speed to 1400 from 2000. Still specialists know best....
The problem with that is that you've potentially cured the symptom, but not the problem...why was your cold idle speed so high in the first place? That's the question I'd be trying to answer.
Re: Idle problem
dan4 wrote: Still TOYOTA know best....
yes, they designed the system to work in an intentional way, if you 'adjust' you are just masking the fault, it'll always be present.
quite simple really, just like Denso supply parts in Toyota boxes, You couldnt grasp that concept, so you've little chance with the above.
Re: Idle problem
ashley wrote:dan4 wrote:They dont specify adjustment in the workshop manual however there is an end stop adjustment and adjustment of the bimetallic spring placement. Dropped my cold idle speed to 1400 from 2000. Still specialists know best....
The problem with that is that you've potentially cured the symptom, but not the problem...why was your cold idle speed so high in the first place? That's the question I'd be trying to answer.
Wear on the spring, which in turn changes the scope the ecu has to open/close the valve. Slotted holes must be for something other than adjustment, silly me Its not a new thing, its been implemented in the states for a while
Re: Idle problem
As long as you're happy dude, far be it for me to try to give you advice
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Re: Idle problem
dan4 wrote:Wear on the spring, which in turn changes the scope the ecu has to open/close the valve.
Of course! Stupid me!
OP removes engine, dismantles, rebuilds. Idle perfect before removal. Bad on refitting.
ISC spring has gone bad whislt engine out!
Toyota not so stupid after all. Shame they left it out of BGB though.
Re: Idle problem
Op also made it appear as if the engine was built to that spec before refitting?
Re: Idle problem
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...damn these cheap replacement parts!
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...damn these cheap replacement parts!
GTMatt wrote:Could anyone advise please, I have recently had my rev 3 turbo engine rebuilt, it is still with the garage as have reached the last hurdle of starting it up and it won't self sustain itself on idle (aka no throttle input and it stalls).
Engine has got Hks 264 cams
86.5mm cp pistons
Eagle rods
All bearings and studs replaced by the usuals (arp etc)
Currently running with standard fuelling, ecu and turbo.
Runs very smoothly when any throttle is engaged, even just holding the throttle to run it at 850-1000 rpm and it runs fine, but as soon as you let off the throttle it will stall.
Cam and ignition timing is set as it should be, injector seals have been replaced as believed it was a leak from around that area, all pipes have been checked and checked again, and no engine error codes being displayed when you perform the diagnostics trouble code procedure.
Can anyone suggest anything/ experienced something similar?
Cheers
Matt
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Re: Idle problem
What a load of tosh.
Moving the throttle stop will change the idle but also willy up the tps calibration.
You've got a 0.5mm parameter on the iscv, and the spring wore this much? lol
Clearly the engine isn't getting the air it requires on idle. Just find out why. simples.
Moving the throttle stop will change the idle but also willy up the tps calibration.
You've got a 0.5mm parameter on the iscv, and the spring wore this much? lol
Clearly the engine isn't getting the air it requires on idle. Just find out why. simples.