Wyvern
NAXJA Forum User
- Location
- Upstate New York
Hey all,
I've been lurking a lot of helpful threads for a few weeks now trying to diagnose the long crank and hard starting my 1996 Cherokee XJ. I'm running out of things to test so I figured I'd make a thread.
My Jeep cranks for around 5-10 long seconds and then stumbles to a start only after repeatedly and aggressively blipping the throttle to bring the RPMs up. At first while cranking there's no RPM change but as the truck stumbles, blipping the throttle clearly brings the tach up.
When the truck has warmed up it hard starts almost immediately but still stumbles a bit for a second or two before it catches its breath.
Once started my Jeep runs like a top. No coughing/shuddering. Great on the freeway. No change in MPGs.
This weekend I load tested the 3 year old battery and it failed loading twice. It was under warranty so I got a fresh one and put it in this morning--no change in the starting issue.
I tested pressure off of the Schrader valve multiple times both while the truck was running, immediately after turning the truck off, and 15-30 minutes after turning the truck off. All values were nominal at 49 PSI and pressure values remained above 30 PSI even up to an hour after shutoff.
This March I changed both the fuel pump assembly, the fuel filter, the 3/8ths hose from the filter to the tank bulkhead, and the fuel injectors from EV1s to EV4 injectors.
I tested the crank trigger pig tail connector with my multimeter and got the right resistance values from the crank trigger test on the forum here. My crank trigger and coil pickup are only 2 years old and since the truck does eventually start and runs great (no random shutoffs or stalls) I am hesitant to change the sensor on a hunch.
Additionally since the truck does start and run I know I am getting spark eventually and have confirmed I am getting fuel at the rail as noted above.
One last important thing to note is that for around a year now I no longer can get my OBDII scanner tool to communicate with my Jeep. Works with all of my other cars but the Jeep crosses its arms and says "no". I have tried other OBDII scanner tools as well and none them can get a read. This truck was supposedly the first year of OBDII XJ's and OBDII is a backwards compatible communications protocol so I have no idea what this could mean beyond the ECMs OBDII communications port going on the fritz. Could be unrelated but I figured I'd mention it.
I greatly appreciate any suggestions, guesses, or any form of further insight.
Thanks!
-Wyvern
I've been lurking a lot of helpful threads for a few weeks now trying to diagnose the long crank and hard starting my 1996 Cherokee XJ. I'm running out of things to test so I figured I'd make a thread.
My Jeep cranks for around 5-10 long seconds and then stumbles to a start only after repeatedly and aggressively blipping the throttle to bring the RPMs up. At first while cranking there's no RPM change but as the truck stumbles, blipping the throttle clearly brings the tach up.
When the truck has warmed up it hard starts almost immediately but still stumbles a bit for a second or two before it catches its breath.
Once started my Jeep runs like a top. No coughing/shuddering. Great on the freeway. No change in MPGs.
This weekend I load tested the 3 year old battery and it failed loading twice. It was under warranty so I got a fresh one and put it in this morning--no change in the starting issue.
I tested pressure off of the Schrader valve multiple times both while the truck was running, immediately after turning the truck off, and 15-30 minutes after turning the truck off. All values were nominal at 49 PSI and pressure values remained above 30 PSI even up to an hour after shutoff.
This March I changed both the fuel pump assembly, the fuel filter, the 3/8ths hose from the filter to the tank bulkhead, and the fuel injectors from EV1s to EV4 injectors.
I tested the crank trigger pig tail connector with my multimeter and got the right resistance values from the crank trigger test on the forum here. My crank trigger and coil pickup are only 2 years old and since the truck does eventually start and runs great (no random shutoffs or stalls) I am hesitant to change the sensor on a hunch.
Additionally since the truck does start and run I know I am getting spark eventually and have confirmed I am getting fuel at the rail as noted above.
One last important thing to note is that for around a year now I no longer can get my OBDII scanner tool to communicate with my Jeep. Works with all of my other cars but the Jeep crosses its arms and says "no". I have tried other OBDII scanner tools as well and none them can get a read. This truck was supposedly the first year of OBDII XJ's and OBDII is a backwards compatible communications protocol so I have no idea what this could mean beyond the ECMs OBDII communications port going on the fritz. Could be unrelated but I figured I'd mention it.
I greatly appreciate any suggestions, guesses, or any form of further insight.
Thanks!
-Wyvern