ALFAGTV6.COM

[kredden]

Been reading as much as I can and am getting close to ordering my MS kit to put in my stock Verde 3.0L from DIYAutoTune and just wanted to get a couple opinions.

I'm planning on ordering:
MS-II v3.0 kit
Stimulator v2.2 kit
LC-1 wideband controller with sensor

Rather than pulling an air temp sensor out of a good Milano AFM I was thinking about ordering the GM Closed Elelement CLT/IAT sensor with Pigtail along with the bung. Does this make sense? I assume this will work fine and will make that component easier to replace in the future if needed...

Also I'm planning on going with a Bosch 0 280 122 001 TPS out of a Volvo 850/Saab 900 etc. It sounded like a good idea for 255 discrete inputs rather than just the idle, on, full throttle that ours has. Are there really noticeable benefits to doing this or is it just adding complexity to my project?

Murray, I noticed in one post you said "I've just built a second MSII (winter is long in Canada Evil or Very Mad ) and it's 100% built per the standard MSII instructions." (http://www.alfagtv6.com/bb/viewtopic.php?t=2129). Does this mean that none of the mods noted in Steve's build notes are needed anymore, just the stock MS instructions?

Another question I have is that I see you can remove the cold start injector when using MS. Is this because MS controls the injector enrichment better than the Bosch ECU during cold start so it is no longer needed? I think I know the answer but just checking .

My last question (for now) is on removing the AFM. What allows you to do this? The more discrete TPS? If you stick with the stock TPS then you cannot do this right? Or am I missing something?

Thanks in advance!

Kevin

[David]

Kevin,

Use the GM IAT sensor it will work fine. If you can get hold of a busted AFM, use the socket to wire in the IAT sensor and any other extra wires you need.

With the throttle body you can go down the path you are suggesting or use the original one and use the MAP option. The are various schools of thought as to whether TPS or MAP is better. It has been suggested that with large throttle body intakes MAP is more responsive. I can't comment as I have only used the MAP option with the original TPS.

You don't need the Cold Start injector as this is handled in the MS cranking and cold start enrichments.

You also don't need the AFM either with the TPS or MAP option.

Hope this helps.

David

[Murray]

Kevin some replies:
1) The GM IAT sensor is a good idea,as you stated they're easy to find.

2) I went with the Volvo TPS.You do want to have a true TPS as you will probably find that best acceleration enrichment is acheived by blending TPS/dot and MAP/dot.With no TPS you lose that flexibility.

3) Basically you can build your MSII per the instructions without any of "Steve's" internal mods.Most of the issues which came up in MSI have been resolved.I do recommend that you wire out to an L-Jet plug so that you can maintain your stock wiring and switch back to L-Jet quickly if the need arises.

4) The function of the CSI is eliminated with MSII.The cold-start fuel is provided by your injectors and it works very well.

5) The AFM can be removed because the MAP & IAT sensors measure air volume and density and the AFM becomes redundant.Rip the sucker out of there

[P.Webb]

Regarding retaining the CSI:

Remember the MS has 2 settings. A priming pulse and a cranking pulse. The CSI sort of does both on the L-jet with the thermo time switch.

The priming pulse is a fixed pulse when power is applied to the MS. The cranking pulse is temperature variable during cranking which is default defined as 300rpm but can be changed.

Regarding the AFM. I would suggest drilling and tapping the plenum with the 1/4" NPT for the GM IAT. Use some sensor-safe RTV to seal it in there and run a wire to the AFM plug to retain the stock wiring. The AFM is, of course, obsolete with a speed/density system. The ideal gas law that MS is based on needs pressure and temperature to calculate density.

Doing the fuel pump mod for a street car is a better idea than hot-wiring the pump to the ignition. The fuel pump starts when it senses RPM (and during the priming pulse) for safety reasons. If you were to crash the car and the engine stalled, the fuel pump would shut off so it won't spray fuel everywhere should you break a line in an accident.

HTH

-Peter

[kredden]

I finally got around to ordering my MS-II kit, stim kit, Wideband controller & sensor, the GM IAT sensor! My goal is to have it build, installed, and running by the convention this year. Maybe I'll get better mileage now that my wallet is significantly lighter .

Kevin

[P.Webb]

I finally got around to ordering my MS-II kit, stim kit, Wideband controller & sensor, the GM IAT sensor! My goal is to have it build, installed, and running by the convention this year. Maybe I'll get better mileage now that my wallet is significantly lighter .

Kevin

FWIW, when I'm on the highway and not driving like a maniac I get about 28mpg. Leadfooting it I get 15-18mpg, on the track all out I get about 11mpg with the MS. On the highway or long trips I turn the accel enrichment down or off. It makes a surprising difference in mileage.

-Peter

[Barry]

Hello Peter Webb!!Long time no hear!..

[mjr]

Doing the fuel pump mod for a street car is a better idea than hot-wiring the pump to the ignition. The fuel pump starts when it senses RPM (and during the priming pulse) for safety reasons. If you were to crash the car and the engine stalled, the fuel pump would shut off so it won't spray fuel everywhere should you break a line in an accident.

HTH




excuse my ignorance, but are are you saying that MS config should be set to cranking pulse only, with no priming pulse? ie pump only comes on at your default defined rpm setting, rather than when power is applied to MS.?

doesnt the standard inertia switch/crash relay deal with the fuel pump in a heavy impact anyway?

[P.Webb]

Doing the fuel pump mod for a street car is a better idea than hot-wiring the pump to the ignition. The fuel pump starts when it senses RPM (and during the priming pulse) for safety reasons. If you were to crash the car and the engine stalled, the fuel pump would shut off so it won't spray fuel everywhere should you break a line in an accident.

HTH




excuse my ignorance, but are are you saying that MS config should be set to cranking pulse only, with no priming pulse? ie pump only comes on at your default defined rpm setting, rather than when power is applied to MS.?

doesnt the standard inertia switch/crash relay deal with the fuel pump in a heavy impact anyway?

Sorry my ommision. The MS does start the pump momentarily for the priming pulse but it will not turn the pump on again until it sees 300rpm (configurable).

I'm not sure when they disconitnued that silly inertia switch. I forgot the GTV6 even continued it. All the Spica cars had it because it had no way of turning off the pump electronically. With the L-Jet it superfluous because the pump starts with the AFM flap.

FWIW, the L-Jet Spiders switch the fuel pump from RPM too. It takes crank angle and RPM from the flywheel.

-Peter

[mjr]

So I take it that the L jet deals with shutting the fpump down in a shunt by way of a closed AFM flap? (what if the afm flap is tuck open though?), surely thats why the inertia switch is a secondary? my 83 still has an inertia switch wired in, I have never tried activating it, to see if it works though.

So if MS is configured to say 300rpm crank to turn the pump on properly, it doesn'it deal with shutting it off also? hence why a modification is required to deal with this? sorry for all the questions, but I have just ordered my MS11 3, and am a bit confused about the fuel pump situ after reading various threads about it.

[P.Webb]

So I take it that the L jet deals with shutting the fpump down in a shunt by way of a closed AFM flap? (what if the afm flap is tuck open though?), surely thats why the inertia switch is a secondary? my 83 still has an inertia switch wired in, I have never tried activating it, to see if it works though.

So if MS is configured to say 300rpm crank to turn the pump on properly, it doesn'it deal with shutting it off also? hence why a modification is required to deal with this? sorry for all the questions, but I have just ordered my MS11 3, and am a bit confused about the fuel pump situ after reading various threads about it.

Yes, it does deal with turning it on and off. Let's go back to the beginning and clear up any confusion.

1) The MS is responsible for turning the fuel pump on and off as a safety precaution. Perhaps this is a legal thing for the US market since most cars have this safety feature from the factory, including Alfas.

2) Speaking to #1, if it was mandated by law from the manufacturer, that would explain why the intertia switch is there for Spica cars. I can't speak to why it was conitnued on the early L-Jet cars. Alfa didn't ask my opinion.

3) It's possible the AFM could stick open but unlikely. On the Milano(75) the fuel pump is switched purely from the AFM switch. On L-Jet Spiders, it's switched by RPM just like the MS.

4) The MS - being a generic solution - needs to accomodate this and, IMO, the design is sound using RPM. Many OEM's use this method so we probably can't credit B&G with the design, just the good sense to incorporate it.

5) The L-Jetronic cars turn on the fuel pump through pin 88a of the combi relay. The MS turns on the fuel pump by supplying 12v to an external relay. This scheme will not work electrically with the stock L-Jet relay so a modification to the artwork of the MS is needed to supply ground to 88a to turn on the fuel pump.

6) The software functions exactly as designed using RPM to turn the pump on and off and is unaware of the electrical change to the pump switch itself.

7) The pump turns on momentarily for the priming pulse then turns off until it detects at least 300rpm during cranking. When it detects less than 300 RPM, like if the engine were to stall in an accident or rollover, the MS turns the pump off.

The fuel pressure regulator stock delivers 36psi to the fuel rail and returns the excess fuel to the tank by bleeding the pressure to the return line. This serves 2 purposes. To cool the fuel as it returns to the tank and to ensure there is enough fuel and pressure in the rail to supply the injector pulsewidth at any RPM. Obviously, the lower the RPM, the less fuel is used and the more fuel is returned to the tank.

9) If one of those lines were to rupture in an accident, you'd have high-pressure, low-flow on the high side and low-pressure, high-flow on the low side of the fuel line. Neither of which you want in a crashed car. When the pump turns off, no fuel is flowing through or out of the lines to cause a fire, supply a fire, or poison the occupants (remember the return line travels *through* the interior of the car).

10) Therefore, turning the pump off when the motor isn't running is a really good idea.

That said, if you were not concerned with this kind of thing, like racing where you might have an external shutoff mandated by your sanctioning body, you might hotwire the pump to the ignition. The pump starts when the key is turned on a street car, or the pump is started by an internal switch by the driver.

On my cars, the Milano has the pump hotiwred to the ignition and the Giulia Super race car has an internal switch for each of the 2 pumps I run, and both ignitions which are also controlled by the master shutoff switch.

Hope this long essay clarifys things.

-Peter