To those of you who use electromotive engine management

[pjo046]

I have bought a Tec3 system to put on the 280ZXT engine. Also a 240SX throttlebody.

 

My question is: do you have the iddle-motor that can be bought and used with the TEC3? Is this a necessity for me when I don't have A/C or anything like that? If not, do you route some air that bypasses the TB when it is closed? Or can I just adjust the posision of the TB so that it is not fully closed when the tps shows that it is? (This way I get a cleaner looking TB section, and can shave of everything on the TB)

 

And do you use a knock sensor with the TEC3 (or 2) as well?

 

Could anyone give me a file with the proper settings for my TEC3? Have 550 cc low impedance injectors, a sx fuel pressure regulator and a walbro 255 fuel pump. Want to get as broad a powerband as possible, with maximum peak power and torque and good driveability on the streets.

 

Will use a T3/T04B hybrid with stage 5 turbine wheel and 0.63 turbine A/R. A high fi wheel in the T04B compressor. Will give me a flow of 55lb

[rags]

pj,

 

I use a TEC II and don't have an IAC. You can get it to run fairly well without one but I am contemplating installing one if for nothing else than to be able to tweak my idle that much more. I would use a knock sensor. It's good insurance against a poor tune

 

Joe

[zcarnut]

I have bought a Tec3 system to put on the 280ZXT engine. Also a 240SX throttlebody.

 

My question is: do you have the iddle-motor that can be bought and used with the TEC3? Is this a necessity for me when I don't have A/C or anything like that? If not' date=' do you route some air that bypasses the TB when it is closed? Or can I just adjust the posision of the TB so that it is not fully closed when the tps shows that it is? (This way I get a cleaner looking TB section, and can shave of everything on the TB)[/quote']

 

In addition to upsetting the TPS, the problem with using the throttle blade adjustment to set your engine idle rpm is that is changes the ported vacuum advance that is sent to the distributor. The hole drilled for the ported vacuum signal is very close to the throttle blade so even a small adjustment to the position of the blade will uncover the port.

 

Nissan used an external adjustable idle control valve on the turbo ZX’s and the later NA versions. It bolts to the side of the intake manifold. It’s not pretty, but it will allow a fixed amount of air to bypass the throttle blade. However, the main issue with using a fixed air bypass is that the engine idle rpm level can vary as it is subject to engine conditions and engine loading.

 

In addition, they are times when you want to increase the level of the idle speed such like during the engine warm up period (fast idle) or when the AC compressor is energized (improves AC operation). If you have an automatic transmission you can now increase the idle rpm when you are in PARK or NEUTRAL. Automakers are even increasing the idle speed of newer vehicles when the power steering pump is being loaded.

 

An Idle Control Valve (ICV) using a stepper motor under electronic control form can preform all these functions.

 

I don’t have the Electromotive system but I’m using a Bosch ICV from a BMW 525 with my SDS engine management system (which pretty much ignores the engine idle speed concerns). The nice feature of the BMW idle control valve is that it has a “stand alone” analog control module. I placed this control module right next to SDS ECU as some of the input signals (rpm, TPS, engine temp) are used by both modules. I hid the ICV by mounting it under the intake manifold just under the throttle body opening. This allowed a very clean looking setup.

 

The BWM ICV and it’s controller were only $20 (used). I see them on eBay all the time. Saab and Volvo also used similar ICV’s on their 1980's vehicles.

[TimZ]

In addition to upsetting the TPS, the problem with using the throttle blade adjustment to set your engine idle rpm is that is changes the ported vacuum advance that is sent to the distributor. The hole drilled for the ported vacuum signal is very close to the throttle blade so even a small adjustment to the position of the blade will uncover the port.

 

The TEC3 (and TEC2, for that matter) use direct ignition, and thus have no use for the ported vacuum advance signal. Also, both have the controller for the stepper motor-style idle air controller built in, so there is no need for an external controller. Finally, the TPS reading that corresponds to closed throttle is programmable in the TEC.

 

I use the IAC with my TEC2, but plenty of people use it successfully without. The ignition timing based portion of the idle controller in the TEC works surprisingly well on its own, so if you don't need to change idle speeds for things like AC, then an adjustable throttle stop should work just fine.

 

On the knock sensor - yes it is a good idea to have one, but I generally caution people not to blindly trust it. You will still want to listen very carefully for knock, and check to see if the sensor readings correlate. Some people have had good luck with these, but I frankly don't trust mine -I've had times when it said I was detonating when I know it was not, and others when I could hear it pinging and the sensor gave no reading whatsoever.

 

Also, I definitely would not recommend using the knock control feedback until you are certain that the sensor works reliably. Unfortunately this does call for more diligence on your part.

 

Finally, there are a couple of TEC3 users here that can probably send you a .bin file. Assuming that they have a similar setup, a good deal of the settings should be transferable, but do not expect the VE table to be usable as is. Speed-density EFI systems are very dependent on all of the things that influence the amount of air the engine actually ingests for a given rpm/map. There are way too many variables (cam profile, cam timing, turbo efficiency, exhaust restriction, injector size/impedance, fuel rail pressure, etc) to expect that your engine will be "close enough". IMHO, your best bet will to use somebody else's map as a starting point, and then clear out the VE table and start tuning your own. Obviously, start with as low a boost setting as possible, and get that working properly first.

[pjo046]

Thank you very much for the replies. So that means I don't need either the IAC or the knock sensor. I won't tune it to the edge of knocking anyway. And yes, I would just use other persons bin files as a baseline, and tune from there on myself.

 

Thank you very much!

[TimZ]

Thank you very much for the replies. So that means I don't need either the IAC or the knock sensor. I won't tune it to the edge of knocking anyway. And yes' date=' I would just use other persons bin files as a baseline, and tune from there on myself.

 

Thank you very much![/quote']

 

Well, it's still a good idea to have a knock sensor - you just need to be careful how you use it. Did your ZXT engine come with one? If so, I would try to see if that will work with the TEC3's knock sensor input, rather than trying to use some other sensor.

[pjo046]

Not sure yet, as the engine is underway right now. Being shipped from usa to Norway, will be here in the end of january. But I'm gathering the parts for the puzzle! Take a look at my other post where I state the specs of the turbo I'm buying. Tell me what you think!!

[speeder]

I use a TEC 2 with no IAC, and have the idle control set to use igntion only. It works really well even with A/C.