Hi Everyone,
The VEC2 is about two and a half years old now. Initially, the system was developed solely for use with the Supercharger system, so we could properly set the air / fuel ratio and control timing retard. We’ve been through many changes, primarily in software as the system evolved into something useful for naturally aspirated applications.
Some small issues have popped up along the way, which we learned from and corrected.
The check engine light on the Gen3 cars that Bill M. mentioned was resolved by removing a resistor from the circuit board, which had been allowing a small amount of voltage to backfeed into the injectors. When the key was on and the engine was not running, the PCM would recognize the voltage through the ASD relay circuit and set a light for a fan code and oxygen sensor heater. That was interesting to find.
The problem with the V-notch Ken had mention on his NA Gen2 was an initial algorithm error we had when we first introduced the ability to add timing advance. This caused a sharp“V” notch on a dyno graph about 7 out of 11 pulls. That was fixed with a firmware change. The most current firmware is 5.79
The systems are not water proof, but are fairly tolerant of it. Soapy water or salt water can be detrimental. I’ve driven mine in hard Florida rain too many times to remember and haven't had any trouble. We did extended the harness length on the Gen3 cars about a month ago, as we didn’t like the location we had them and have now moved them to under the windshield cowl. If you have one of the shorter harnesses, contact us for an extension (no charge for the part, just shipping if applicable).
In regard to the tach needle jumping, that’s been known to happen on Vipers without VEC2’s. You can do a search on this site and probably find posts relating to this. Most often it’s the battery or one of the main battery connections.
The miss / cough cause can be one of three items. In the Supercharger kits, we include new injector connectors. The VEC2 is far less tolerant of poor injector connections than the stock PCM. We may need to consider putting new connectors in with the stand alone VEC2 kits also. Another possible cause on the naturally aspirated cars is too aggressive of a performance tune. This can easily be diagnosed by inserting a stock program card into the VEC2. If the symptoms go away, the performance program needs to be adjusted slightly, with less timing advance and / or fuel trim adjustment. If the symptom persists, or is aggravated by hot weather, the PCM output for injector duty cycle may be hitting 100%. The VEC2 relies on the pulses from the stock PCM in order to know when to fire each injector and for how long. If the input pulse goes away, as in 100% “on” for the injectors, the VEC2 will not trigger that injector properly. We’ve recently found that reducing the intake air temperature sensor voltage with a simple 5K ohm resistor can help keep the PCM from going to 100% duty cycle.
Of course, all this aside, there can be other problems with the car. Cars with problems are not limited to ones with VEC2’s. We have seen installation errors where wires were not crimped or installed properly also.
We have over 600 VEC2’s in service now. Thankfully, problems are few.
If anyone needs assistance, contact me directly also (in addition to posting) as I don’t get the time to read / post here much. We’re here to help the best that we can.
Regards,
Sean
