Spyder 98 4G63T idle adjustment.

[racefourfun]

I need to bump up my idle a little bit and I was told I may need a ECMLink to do that. Is that true? I don’t have access to one. If that isn’t true, can someone please tell me where the adjustment screw would be if there is such a thing on this engine.
Thanks

 

[pauleyman]

It isn't that simple. The ECU tries to set idle to 750. If you artificially try to alter that it does what it can to get to 750. Idle speed control has a range of motion to get idle where it needs to be based on operating conditions. Base idle speed set screw is on top of the throttle body to help ISC be adjusted for proper range, NOT to adjust idle speed.

Describe why you need this.

Idle speed adjustment is very well documented on this site. Again NOT to change where it is, but to give computer maximum control.

 

[racefourfun]

I have solid motor mounts and if I lightly touch the throttle it will idle much smoother. I thought if I was able to bump the idle up to 800rpm it would be easier to live with.

 

[pauleyman]

I have solid motor mounts and if I lightly touch the throttle it will idle much smoother. I thought if I was able to bump the idle up to 800rpm it would be easier to live with.

Not without computer mods, ECMLink etc. Have you considered the car has a vacuum leak? Needs a tuneup?

Just noticed the car has an AFC and 750 injectors. You might consider going more modern. AFC does not have the ability to adjust ignition. It's a piggyback. Not a true tuning solution.

 

[racefourfun]

I know it doesn’t require a tuneup. I will search for a vacuum leak.
Thanks

 

[pauleyman]

I know it doesn’t require a tuneup. I will search for a vacuum leak.
Thanks

When was your last timing belt change? Consider also your belt isn't timed right or the balance shaft belt has broken. It's happened to me before and the only symptoms was a bit more vibration. Until the belt took out the main belt and bent 8 valves.

 

[racefourfun]

I just had all of that replaced 200 miles ago. The shakes at idle started when I changed the mounts.

If I had a vacuum leak would the engine smooth out and run strong up to the rev limiter (7500 rpm)?

 

[pauleyman]

If I had a vacuum leak would the engine smooth out and run strong up to the rev limiter (7500 rpm)?

If ita a tiny leak yes

 

[racefourfun]

How do you search for a tiny leak???

 

[pauleyman]

I just had all of that replaced 200 miles ago. The shakes at idle started when I changed the mounts.

Per your other thread, solid mounts introduce vibration. It's also likely different for every car. Cars run different weight flywheel and clutches, worn harmonic or different brand harmonic balancer. One car may be exceptionally in tune while another isn't.

How do you search for a tiny leak???

Boost leak test the car.

 

[curt-s]

You'll get idle surge before rev limiter if your idle position switch works

 

[DSMPT]

If I had a vacuum leak would the engine smooth out and run strong up to the rev limiter (7500 rpm)?

Besides the throttle body adjustment. If you have a vacuum leak, that would cause the idle higher, not lower. So if you have a leak, that should be pre throttle plate

Assuming the throttle body is adjusted properly, your BOV is kinda suspicious to me. I would check it.
Do you have an adjustable BOV? If so, check if the valve is open or not at idle. If the valve is open, at least adjust the bolt until the valve gets completely closed or if it's not adjustable, make the BOV recirculated to the intake pipe again. Make it recirculated to the intake pipe is the correct way through.

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Add : I missed this.

if I lightly touch the throttle it will idle much smoother. I thought if I was able to bump the idle up to 800rpm it would be easier to live with.

Maybe the throttle plate is fully closed. The plate should be slightly open if it's adjusted properly.

 

[pauleyman]

You'll get idle surge before rev limiter if your idle position switch works

I don't think that's what he meant. I think k it was would the car running normally off idle up to redline. I replied if the leak is small then yes it probably would.

 

[curt-s]

Add : I missed this.

Maybe the throttle plate is fully closed. The plate should be slightly open if it's adjusted properly.

This is interesting, I've not actually heard this before. Only that the tension on the throttle cable should be just enough to be taught without pulling the throttle open. If you have an IPS, it should just trigger when there's no tension on the cable. You should be able to idle fine with the cable detached. With what are you able to adjust the position of the butterfly when you don't have a physical idle position switch to hold anything open? I've always known the butterfly to be allowed to remain closed on its own. The parts in the FSM I could find only talk about cruise control cable adjustment but not a non-cc cable.

I'm really curious where the adjustment steps are -- perhaps my TBs are missing something.

 

[racefourfun]

My BOV is a factory 1st gen not crushed.

 

[pauleyman]

My BOV is a factory 1st gen not crushed.

But is it recirculated? Your profile suggests it isnt.

 

[DSMPT]

This is interesting, I've not actually heard this before. Only that the tension on the throttle cable should be just enough to be taught without pulling the throttle open. If you have an IPS, it should just trigger when there's no tension on the cable. You should be able to idle fine with the cable detached. With what are you able to adjust the position of the butterfly when you don't have a physical idle position switch to hold anything open? I've always known the butterfly to be allowed to remain closed on its own. The parts in the FSM I could find only talk about cruise control cable adjustment but not a non-cc cable.

I'm really curious where the adjustment steps are -- perhaps my TBs are missing something.

No. You are missing the adjustment of SAS/Stop screw. The 1g IPS and 2g SAS is to determine how much air you want to let in to the engine through the throttle plate when fully closed. This is important to set the idle RPM properly.

Please refer the link below.

2G - Spyder 4g64 Hybrid Turbo

I must be doing something wrong. I set the TPS to .63v, and the engine stalls immediately at idle, only runs if I give it gas.

www.dsmtuners.com

 

[FIBA M - EC17PSE]

No. You are missing the adjustment of SAS/Stop screw. The 1g IPS and 2g SAS is to determine how much air you want to let in to the engine through the throttle plate when fully closed. This is important to set the idle RPM properly.

Please refer the link below.

2G - Spyder 4g64 Hybrid Turbo

I must be doing something wrong. I set the TPS to .63v, and the engine stalls immediately at idle, only runs if I give it gas.

www.dsmtuners.com

The stops are to stop the plate from jamming once snapped shut, not to allow air to bypass. That's the job of the BISS screw. The plate just cannot snap and jam otherwise you create stress on the cable and could snap or stretch it.

I never set TB's up for air flow for these parts. It's not correct and is not used for any air but some will bypass once setup correctly but it's a very small amount. If your BISS is all the way in and you idle then the plates too far open! It needs to stall out. Once it does your plates closed fully and hopefully without bottoming out/jamming.

 

[curt-s]

Ok so I've never had a 2g TB I've always ran a 6bolt with a 1g TB and more recently I've removed the IPS as I didn't figure it was useful anymore since I'm using a 2g TPS. I've always had a sticky plate when actuated by hand, but not noticeable in cabin. This is indeed a good thing that I stumbled across this conversation.

Hmm I guess I can put the IPS back in to keep the plate from going full closed and jamming but adjust it so that it doesn't hold the plate open, just to the point where the butterfly just cracks off fully closed.

That manual page doesn't state anything other than beginning to open. There's no measurement for it so, as Bobby says, it must be to prevent jamming of the valve, should it somehow happen.

I wonder if this is also related to why my ISC has been notoriously difficult to get a consistent 30 out of. The adjustment may not be so linear down that low when the plate is fully closed and not even cracked a fraction of a mm.

 

[DSMPT]

The stops are to stop the llate from jamming once snapped shut.

That's correct that the plate gets stuck sometimes when fully shut and the proper SAS adjustment would avoid that happen. That's one of purpose of the SAS adjusting.

Not to allow air to bypass. Thats the job of the BISS screw.

Bobby totally no offense, but that's not correct. The SAS is also to determine the base idle engine speed. Not only to stop the throttle plate. The BISS is to adjust the air based on it. The plate should still let some air in, if the plate shut the air completely and you have the air only by bypassing when close the throttle, you would probably have more chance to have the engine stalled in some circumstances, especially after the engine gets hot or sudden throttle closing or when you adjust the TB as factory. So to adjust the TB without setting the SAS in the right position is not correct.

Adjusting the BISS and plate position has the same effect to change the engine speed as you know but work differently. For instance, when you have a lightweight flywheel and struggling with engine stall at each stop, you would make the engine stall happened less if you have the throttle plate a bit more open by SAS. By adjusting only the BISS would be limited, it wouldn't work exactly the same as you open the throttle plate by SAS.

Usually you don't need to adjust the SAS since it's already set from factory by marking the position, but many people mess with it. So if the SAS position has been changed previously, then you would have to re-set.

 

[FIBA M - EC17PSE]

That's correct that the plate gets stuck sometimes when fully shut and the proper SAS adjustment would avoid that happen. That's one of purpose of the SAS adjusting.

Bobby totally no offense, but that's not correct. The SAS is also to determine the base idle engine speed. Not only to stop the throttle plate. The BISS is to adjust the air based on it. The plate should still let some air in, if the plate shut the air completely and you have the air only by bypassing when close the throttle, you would probably have more chance to have the engine stalled in some circumstances, especially after the engine gets hot or sudden throttle closing or when you adjust the TB as factory. So to adjust the TB without setting the SAS in the right position is not correct.

Adjusting the BISS and plate position has the same effect to change the engine speed as you know but work differently. For instance, when you have a lightweight flywheel and struggling with engine stall at each stop, you would make the engine stall happened less if you have the throttle plate a bit more open by SAS. By adjusting only the BISS would be limited, it wouldn't work exactly the same as you open the throttle plate by SAS.

Usually you don't need to adjust the SAS since it's already set from factory by marking the position, but many people mess with it. So if the SAS position has been changed previously, then you would have to re-set.

I cannot comment on setups of flywheels, etc, etc but only on what I have rebuilt and used many times so going by my own doings mostly. As I said the SAS is going to keep the plate open a smidge / fraction. Generally just enough to see a small bit of light last it like a HALO and that's all that's needed. Never needed more that that.

On the 1G its just as it touched and with the feeler gauge its how its setup and even then you barely see light. Its faint but there so even stock form is quite closed off. Rebuilt a friends 1g this same way as per how it should be and its no issues with it.

2G while not using an ISC but SAS screw gets the same treatment. I don't believe their is a setting for the plates opening to measure and that's why a feeler gauge is used. This is merely just to stop it from jamming, I never read anywhere about its part of the air flow count but saying that they will know its letting some air bypass but small amounts so won't be enough to sustain idle.

If you got any links to flow on the plate at rest I would like to read them to expand the knowledge on it more. As I can only comment on what the FSM tells on setting up and how I have always done the same on all TB rebuilds. I can only comment on this what I know I'm afraid. But it works and well, has done for years.

 

[99dsmer4g63]

That manual page doesn't state anything other than beginning to open. There's no measurement for it so, as Bobby says

The measurement is 7/8's of a turn further once the screw makes contact with the TB plate on a 1G and 1 1/4 turn for a 2G.

I’ve never heard of a measurement other than the two I mentioned above. The only time I use feeler gauges for the TB is to set the 2g TPS after setting the SAS.

-Daniel

 

[FIBA M - EC17PSE]

Ok so I've never had a 2g TBas I've always ran a 6bolt with a 1g tb and more recently I've removed the IPS as I didn't figure it was useful anymore since I'm using a 2g TPS. I've always had a sticky plate when actuated by hand, but not noticeable in cabin. this is indeed a good thing that I stumbled across this conversation.

Hmm I guess I can put the IPS back in to keep the plate from going full closed and jamming but adjust it so that it doesn't hold the plate open, just to the point where the butterfly just cracks off fully closed.
That manual page doesn't state anything other than beginning to open. There's no measurement for it so, as Bobby says, it must be to prevent jamming of the valve, should it somehow happen.

I wonder if this is also related to why my ISC has been notoriously difficult to get a consistent 30 out of. The adjustment may not be so linear down that low when the plate is fully closed and not even cracked a fraction of a mm.

The ISC just needs to see continuity open/closed circuit. But since your on a 2G tps thats invalid for you now. Same as me as i swapped my 1G to a 2G tps for ease and plus my isc was not working so gave up on that. Tos is more reliable anyway.

My ips is still there to allow it to stay setup correctly and to stop it from jamming closed. The slow releases are fine in general its the SNAP SHUTS that jam the TB and cause issues.

There is a spec on feeler gauges. You can also pre check it up letting the TB close without the cable to also confirm its not jamming once set. Most of the time snapping closed is not a big thing but its also partly due to the expansion of the materials as it heats and closes the gap up.

 

[racefourfun]

But is it recirculated? Your profile suggests it isnt.

Yes it’s hooked up exactly like stock

 

[curt-s]

The measurement is 7/8's of a turn further once the screw makes contact with the TB plate on a 1G and 1 1/4 turn for a 2G.

I’ve never heard of a measurement other than the two I mentioned above. The only time I use feeler gauges for the TB is to set the 2g TPS after setting the SAS.

-Daniel

You are correct. 7/8s of a turn would translate to a known height difference given the thread pitch is consistent, although 7/8 can be -/+ but should remain within reason and fractions of a mm. That translates to a very minor degree difference in plate rotation. I was being too literal in my reading and didn't see the forest for the ballpark values
Thanks for the reminder

The ISC just needs to see continuity open/closed circuit. But since your on a 2G tps thats invalid for you now. Same as me as i swapped my 1G to a 2G tps for ease and plus my isc was not working so gave up on that. Tos is more reliable anyway.

My ips is still there to allow it to stay setup correctly and to stop it from jamming closed. The slow releases are fine in general its the SNAP SHUTS that jam the TB and cause issues.

There is a spec on feeler gauges. You can also pre check it up letting the TB close without the cable to also confirm its not jamming once set. Most of the time snapping closed is not a big thing but its also partly due to the expansion of the materials as it heats and closes the gap up.

Yea, provided i still have my IPS, I'll have to give that a go.
I've always set mine (when I had one) by having the TB closed on its own and setting the IPS to the just making solid, repeatable contact point. However, this has never cracked the plate open. I never used it as a stop; I've always thought the only air allowed to bypass would be through the ISC channel, not around the plate.. even a little bit (besides the ultra tiny gaps)

I'm all for getting rid of a potentially sticky throttle.. thanks for the reminder. I learned something new, that's fun