Tom

I have a custom harness for my 4 cylinder motor made for the G4, prepared by my dealer. Â In it, each of the four injectors has its own injector pin, even though I don't have a cam position sensor and will not be running sequential injection. As a test set-up, I've been working to build a jumper harness so I can plug the g4 box directly into my factory harness, so that I don't have to replace it with the custom G4 harness just yet. Â The factory harness has virtually all the wires as the custom G4 harness. Â However, in the factory harness, I only have 2 injector wires, and each is connected to 2 of the injectors. Â Is there a way to use this wiring with the G4? Â Can I connect the two factory injector wires to inj1 and inj2, only, Â and run in batch mode?Â

I have a red G4 Xtreme with harness built for my car, which I have been slow to install, so is still sitting new in a box. Should I still install the G4 box, or upgrade to the G4+? Is the G4+ pin compatible with the G4 (so that I can use the same harness)? Will Link continue to support the original G4? Is there a chart somewhere comparing the new features of the G4+ over the original G4?

Thanks guys, I found them here in the US.  Â

Are the connectors that plug into the box (and the terminal pins for those connectors) available separately and/or are they standard connectors that can be found at Digikey or the like? I have a full harness for my xtreme, but would like to make an adapter to go from my factor harness to the G4...

Trying to select high impedance injectors. If I use 80lb Siemens FI114992 injectors, can I select the Siemens 107961 in the PCLink software? They are the same family of injectors, just the 80lb versions instead of the 60lb version listed in PCLink. Also, what are the 'Bosch 1000H' injectors listed in PCLink? Are those the new high impedance 1000cc Bosch injectors, part # 0 280 158 279?

Thanks. Â The manual is not wrong, I just did not realize that peak and hold isn't available on my ecu. One last question on this point: Â the harness I received has all the +14v wires tied together inside the haness for the injectors, but has 4 separate wires running from inj1 - inj4 to drive my 4 injectors. Â Do the resistors need to be on the +14v side of the injector? Â Given how my harness is wired it would be much easier to put the injectors in-line in each of the injector output wires, but the manual shows it on the +14v side...

Also, the manual seems to say that running injectors in 'peak and hold' mode eliminates the need for resistors even on a Xtreme red. Â Is that right?

Well that's unfortunate. My harness is all wired up with no ballasts. I'll have to call my dealer and understand where we went wrong. He configured the start up map for these injectors so not like that was unclear. Were there ever red Xtreme's that drove low impedance injectors? Also, the manual seems to be illogical with regard to the value of the resistor to use. I copied it below -- it's has the ballast values listed backwards, right? Why would you use a lower ballast for a lower impedance injector? I would the goal is to get the total resistance up to 5 or 6 ohms at least, no? 'If the injector impedance is LESS THAN 2 Ohms, use 2R2 (2.2 Ohm) ballast. If the injector impedance is between 2 and 6 Ohms, use 4R7 (4.7 Ohm) ballast. If the injector impedance is greater than 6 Ohms, use no ballast.' Â

??

Page 42 of the wire-in G4 manual says that I need ballast resistors to run low impedance (Siemans 3105) injectors on a red Xtreme. Â My dealer told me the Xtreme could drive these injectors without ballast resistors. Â Is the manual out of date and/or how can I tell for sure whether I need resistors or not. Â My G4 is red and looks like the one shown in the brochure on this website and I just updated the firmware to 4.9.3, if any of that helps.

Worked like a champ, thanks! Now onward to wiring it in...

Perfect. Will do, thanks.

Ok, baby steps, but I was able to get the ECU to connect to the computer. Didn't really do anything differently, but tried connecting in different order, etc. and it worked. So that's good, thanks. Next question - my ECU has firmware 4.8.1 and I see that the latest is 4.9.3. When I looked at the firmware upgrade help file, it said it is recommended for the dealer to upgrade the firmware as there are features that may need to be configured. When I did click on firmware upgrade I did not get the DOS-based screen shown in the help file, but rather a pop-up box warning that the ECU must disconnect? So, is it worth updating to 4.9.3 from 4.8.1? If so, should I really send it back to the dealer or can I do it myself and just click through the warnings?

I am preparing to install my wire-in G4 extreme. The dealer supplied a harness for my car. I have noticed that the colors in the G4 install manual do not match the wire colors in my harness. There are lots of wires with the same colors in my harness (red, black, brown, white, almost none with tracer stripes). Is that normal? Makes it harder to reference the manual and trace wires if nothing else... Second, I had to trace back to the ECU connectors with a multimeter to find where the MAP was wired in (it is AN 5) and in doing so I noticed that it (and perhaps some of the other sensors) are wired to GROUND (pin 34 in plug A)  rather than to a SENSOR GROUND (such as pin 24 in plug A). Is that ok and what is the difference between a SENSOR GROUND and GROUND? Â

I have not yet installed my G4 Extreme (wire-in). Before I do, can I upgrade the firmware now by supplying power only to the ECU (with the rest of it not yet hooked up)?  Just thought, that way, if I had trouble updating the firmware, I'd have time to sort it before the old engine management is removed and the Link is installed.....

Maybe I'll try more specific questions...   1. So all 3 ECU's have the same onboard MAP sensor, which reads up to 1.5 bar (about 21psi boost)? 2. Only the Extreme can switch between low and high impedance injectors via software? 3. Can you switch between boost setttings on the fly from the cockpit with all three ECU's? 4. Is the Knock Block better than the knock control built into the Extreme?

Trying to decide on which ECU for my 86 Porsche 944 turbo. I've read the features, but am having a difficult time understanding the practical differences between the 3 ECU's.  Is there a chart somewhere that compares the differences? Does the extreme have knockblock built in? Is there a difference in terms of cockpit adjustable maps? For those of you with knockblock on turbo cars, do you think it was worth it?Â