injector pulse 0 while driving?

[obx tsi]

is it normal for the injector pulse to be a zero during driving? while logging i have noticed that sometimes it drops to zero, if this is a problem what should i look for a the cause? im a logging with a palm running mmcd.

 

[steve]

It will drop to 0 when the IPS closes. If your TPS looks like the throttle is closed that would explain the IPW of 0. The ECU is shutting the injectors off during deceleration.

If you seeing a IPW of 0 at WOT then your looking at fuel cut.

Steve

 

[obx tsi]

ok so this is normal but only if my foot is off the throttle and im slowing down. thanks.

 

[winter-beater]

im kinda new to this whole dsm thing but i bought a 91 tsi awd figuring it would be a good winter car... but i ran into this problem the other morning ... i have no injector pulse... so i took my daily driver and went to work ,... cam home and it started ........... so i replaced the ecu and nuttin but what i have noticed is i have no injector pulse when it is cold out ... as soon as it warms up i have and injector pulse .......... any ideas

 

[steve]

iso i replaced the ecu and nuttin but what i have noticed is i have no injector pulse when it is cold out ... as soon as it warms up i have and injector pulse .......... any ideas

You need to do some diagnostic work and figure out where the break is.
First are you losing all the injectors or some?
How are you checking for the injector pulse?

The injectors are in the middle of a circuit between the battery and the ECU. On the battery side you have the MPI fuse, MPI relay, Injector resistors, the injector, and then the ECU to provide ground when the injector is to fire.

When the injector isn't firing you should see battery voltage all the way to the ECU pin for each injector. If you don't then something has opened and you have to work back until you see power again.

Steve

 

[winter-beater]

i have zero wen the temps are cold... but as soon as it warms up i loose all injector pulse...what i have done tho is wen it dosnt start i use a heat gun to warm up the resistor and that dosnt work but i gues i could have a bad ground or suttin on the ecu ... the only sucky part about this is i can only work on it sum times because it works wen the temps are above 25deg