Chrysler Repair: 98 sebring lxi 2.5L: no fuel injector pulsation
Questionim getting fuel to rail and spark. no pulse from injectors and new crankshaft position sensor still nothing what could it be
AnswerHi Sam,
If you are getting spark and fuel pump action then the ASD relay is being activated which would only happen if the pulsations from both the crankshaft and the distributor (cam shaft) sensors were working. That means that also the injector drivers should be pulsing in synchrony as well. However, if the distributor sensor were marginal then the pulsations of the injectors might be absent.
The injector will pulse when it has 12v one wire and an intermittent grounding pulse on the driver wire. The only item that I can see in the circuit for the injectors that would kill their pulsations is that the 12v from the ASD output is not being applied to the injectors. The only reasons for that are either that the black/red common wire that goes from the ASD to the injectors is "open", or that either of the heated upstream or downstream oxygen sensors that are also connected to that same black/red wire have that wire shorted to ground. The wires between the sensor and its plug are very fine and easily damaged (shorted).
So I would start by checking for the presence of 12v on the black/red wire at one of the injectors while you are cranking over the engine, and if it is absent then I would unplug each of the oxygen sensors (one at a time) to see if that restores the 12v supply voltage to the injectors. If not, then the 12v wire from the ASD to the injectors is 'open'.
If you have the 12v on the black/orange wire at one injector then I suspect that the cam sensor inside the distributor is weak. You could check for a fault code using the ignition key: on-off-on-off-on and leave on doing that in 5 seconds or less elapsed time. Then watch to odometer window to see if the mileage reading was replaced by a P0340 which is the fault code for that distributor sensor.
Please read the PS (below) and respond to it.
Thanks,
Roland
