Vague Idle Issue
- Thread starter Entaran
- Start date
Help Support 4GTuner:
I'm not sure if someone has already has said this (I may have missed it) but have you checked the setting of your idle position switch?
I've had two cars with very bad idle and fitting FIAV bypass plate is the best thing I've ever done to those cars! After many hours pulling my hair out trying to find vac leaks etc
Good luck
I've had two cars with very bad idle and fitting FIAV bypass plate is the best thing I've ever done to those cars! After many hours pulling my hair out trying to find vac leaks etc
Good luck
Entaran
Well-Known Member
Thanks baz and trav.
And yeah trav, I'm gonna start looking for a proper harmonic balancer as I'm not sure this crank pulley is properly balanced anyway, it makes some pretty fucking awesome vibrations at like 7200 rpm which I initially thought was the diff, but it's coming from the front of the car somewhere.
Had also thought maybe it was gearbox bearings, but the gearbox shifts silky smooth and doesn't whine or otherwise make noise.
And yeah trav, I'm gonna start looking for a proper harmonic balancer as I'm not sure this crank pulley is properly balanced anyway, it makes some pretty fucking awesome vibrations at like 7200 rpm which I initially thought was the diff, but it's coming from the front of the car somewhere.
Had also thought maybe it was gearbox bearings, but the gearbox shifts silky smooth and doesn't whine or otherwise make noise.
Entaran
Well-Known Member
MDK87 said:I'm not sure if someone has already has said this (I may have missed it) but have you checked the setting of your idle position switch?
I've had two cars with very bad idle and fitting FIAV bypass plate is the best thing I've ever done to those cars! After many hours pulling my hair out trying to find vac leaks etc
Good luck
The idle stepper controller? It's brand new mate, fitted 5 weeks ago. And I have bypassed the FIAV too. That fixed 3 issues just by doing that on its own
Gooch
Member
Solution
Here I have a solution and I know I am great!!
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C problem solved :lol:
Here I have a solution and I know I am great!!
Your forged motor goes into my Track car and you get my track car motor :thumbsup:
C problem solved :lol:
Entaran
Well-Known Member
lol
Entaran said:The idle stepper controller? It's brand new mate, fitted 5 weeks ago. And I have bypassed the FIAV too. That fixed 3 issues just by doing that on its own
Nah mate I meant the idle switch screwed into the back of the throttle body. It's a switch that is grounded when the throttle plate is at idle position. It's position is adjustable, maybe it somehow came out of adjustment, or the switch contacts are dirty. Sometimes it doesn't ground properly and the action of tapping the accelerator quickly gives the spring enough return "oomph" to properly connect the switch to ground telling the ECU that the engine is in idle state.
I thought there was a writeup on setting it on vfaq but I can't find it atm.
The switch I'm talking about can clearly be seen in the 8th picture from the bottom -
http://www.plymouthlaser.com/tbor.htm
The switch I'm talking about can clearly be seen in the 8th picture from the bottom -
http://www.plymouthlaser.com/tbor.htm
Entaran
Well-Known Member
Thanks mate, I'll have a looksee. That may very well be it because if you lightly tap the throttle it generally sorts itself out. And today it's generally been idling fine
boostboy76
Member
Yeah, reading the DSM forums, a lot of people tend to block or bypass the FIAV (Fast Idle Air Valve) in an attempt to cure erratic idle problems.
You can buy custom made blockoff or bypass plates from the states, don't know about here?
http://www.slowboyracing.com/product.php?productid=6012&cat=4673&page=1
You can buy custom made blockoff or bypass plates from the states, don't know about here?
http://www.slowboyracing.com/product.php?productid=6012&cat=4673&page=1
Entaran
Well-Known Member
Again, have long since blocked off the FIAV.
Do you still have the small bracket that bolts onto the top left hand bolt on the trottle body elbow, with the other end having a screw going through it, to screw to the throttle body? (i took picks but cant find the cable to upload them).
Its thin, doesn carry a load just links the two for a ground from what i can gather.
The 'throttle closed switch' just grounds when your off the throttle compleatly.
If this cant ground the idle races.
On my car we thought it was the switch, tried a few things...
It turned out the little bracket provided a solid path for the ground. with out it the ground was inconsistant probably because of the gasket ect.
The ecu couldnt see the switch at times and raced up and down, soon as i bolted it back on it was perfect and the ecu must have setting for when it know yous off the throttle.
I think it ignores alot of the air reverbiration at idle from the afm and holds a steady idle..
Its thin, doesn carry a load just links the two for a ground from what i can gather.
The 'throttle closed switch' just grounds when your off the throttle compleatly.
If this cant ground the idle races.
On my car we thought it was the switch, tried a few things...
It turned out the little bracket provided a solid path for the ground. with out it the ground was inconsistant probably because of the gasket ect.
The ecu couldnt see the switch at times and raced up and down, soon as i bolted it back on it was perfect and the ecu must have setting for when it know yous off the throttle.
I think it ignores alot of the air reverbiration at idle from the afm and holds a steady idle..
If you took the bracket off doing other stuff, just try having some wire go from the throttle body elbow to the throttle body to link the grounding path for the switch.
Theres an engine bay ground coming off the throttle body so it just links to the elbow and the switch.
Theres an engine bay ground coming off the throttle body so it just links to the elbow and the switch.
Entaran
Well-Known Member
Gah. FFS. I took that bracket off ages ago because I thought it was irrelevant.
Entaran
Well-Known Member
I put the bracket back on. didn't fix it, but it did make it better.
Next step, intake leak testing. But 48 hours away from the car first. Before I throw a match down the fuel tank.
Next step, intake leak testing. But 48 hours away from the car first. Before I throw a match down the fuel tank.
Entaran
Well-Known Member
Ok Problem Fixed.
Issues were:
Idle switch -way- out of adjustment.
Idle switch contacts completely black, barely getting any current through.
Idle switch loom connection rooted, had to rewire.
TPS totally out of adjustment. 0.5k resistance closed, 4.3k open. Now 0.9k closed, 4.7k open. 4.7k is as much as it gets, don't know if this means a broken TPS but meh, it works now.
BISS was out of adjustment once I cleaned everything up. Idle now way back down at 770rpm +/-. Was at 1200rpm
Intake elbow -> TB gasket was blown, made a new one.
Refitted that bracket thing that milkandoj talked about.
FIAV was already bypassed.
Need to take off those coolant hoses and loop them around in a circle I think. They are damaged so won't hurt to remove them.
Issues were:
Idle switch -way- out of adjustment.
Idle switch contacts completely black, barely getting any current through.
Idle switch loom connection rooted, had to rewire.
TPS totally out of adjustment. 0.5k resistance closed, 4.3k open. Now 0.9k closed, 4.7k open. 4.7k is as much as it gets, don't know if this means a broken TPS but meh, it works now.
BISS was out of adjustment once I cleaned everything up. Idle now way back down at 770rpm +/-. Was at 1200rpm
Intake elbow -> TB gasket was blown, made a new one.
Refitted that bracket thing that milkandoj talked about.
FIAV was already bypassed.
Need to take off those coolant hoses and loop them around in a circle I think. They are damaged so won't hurt to remove them.
Congrats, i bet those cams sound good now! And the car doesn sound sick. When my idle was up the shit it sounded like the car was farked.
(this is a bit random...)
Do they just throb like rut, rut, rut, rut.
Or more like the lopey/ jumpy idle like rutt ta ta, rutt ta ta
i LOVE the sound of cams:lol:
(this is a bit random...)
Do they just throb like rut, rut, rut, rut.
Or more like the lopey/ jumpy idle like rutt ta ta, rutt ta ta
i LOVE the sound of cams:lol:
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