viper 791 think i have a bad brain

ive had the alarm in for about a year (a 2003 escape).starting today,the car would start,run anywhere between 10-40 sec,die then remote start again and again.i tried starting the car and do tach relearn.that did nothing.then i thought maybe its the bypass.put the key in,turned it to on,then remote started it.that went good,but about 10-15 sec later all the dash lights flashed and the viper tried to remote start the car,a lot of grinding going on.so after that,i turned the car off,remote started it,a lot of grinding,then it started but kept on spinning the starter.i dont know whats going on with it.any ideas?

Seriously doubt the unit is bad. First, when you try the key in the ignition trick, don't turn the key on! Simply set it in the ignition. BUT...thats not your probelm as the immobilzer on a Ford only is needed for the start. After the car is actually running it doen't need to see the key chip. More likely the problem is tach related. Try reprogramming the unit to Voltage sense and see if it works then....Mike M2

Tech Manager

CS Dealer Services

ok,changing it to voltage worked fine.what could have happened to the tach output?

I would check the connection, then re-learn the tach and see what happens....Mike M2

Tech Manager

CS Dealer Services

i checked the tach wire and everything seemed fime.did tach relearn and it did the same thing.but works great on voltage sence.

Where do you live?  If your in a warmer part of the country leave it voltage and forget about it.  If your up north you will need that tach.  Remember FORD = FUEL. Advanced MECP

i disconnected the tach wire,checked the connection,and resoldered it.no corossion or nothing like that.when its in tach mode.it continues to crank after its running.but other times it will start fine,then die 30-45 sec later.everything is fine in voltage sence

is tach connected to a fuel injector or an ignition coil? DEI products (such as your viper) need an injector

right to the injector in the front of the motor