2004 grand 4l engine dies on highway
05-31-2017, 08:04 AM
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Model: Cherokee
2004 grand 4l engine dies on highway
About 6 months ago there was occasional 2 sec loss of power on hyw, it grew to stalling after start up and restarted no problem. Then in traffic it would stall and last time wouldn't start until 3rd attempt. I have OBD2 codes P0442 and P0455 with no freeze frame on 422 which means 455 is the primary fault.
I removed, batt, coolant reservoir, ECM and check all harness for fouling on frames / bolts or damaged wiring all looks good.
All spark plugs were replaced 3 months ago, remove throttle body, disassembled everything and cleaned including sensor on top of intake.
The result was no further codes, idle and throttle response much better with no stalling or rough idle. After driving for 4 hours went back onto highway 3 hrs later thinking All was good? Within 4 minutes engine lost complete power and died at 60mph while in drive coasted out of fast lane to roll off hyw to exit and about 10 sec of coasting engine began running itself maybe by hyd pressure thru torque converter- decided to get back on hyw and it dies again about 2 minutes later just at next exit. Check engine lite came on and I turned around and made it home without towing. One item in freeze frame data odd is spark advance -59? And vehicle speed indicated 158mph I went to look at Evap canister and found bracket completely corroded which have one on order from bone yard today. The code for small and large vacuum leak will be addressed first - I would be grateful to anyone who has proper vacuum diagram for 2004 grand Cherokee with 6cy 4 liter engine and of course any finding from past experience - many thanks - Steven
I removed, batt, coolant reservoir, ECM and check all harness for fouling on frames / bolts or damaged wiring all looks good.
All spark plugs were replaced 3 months ago, remove throttle body, disassembled everything and cleaned including sensor on top of intake.
The result was no further codes, idle and throttle response much better with no stalling or rough idle. After driving for 4 hours went back onto highway 3 hrs later thinking All was good? Within 4 minutes engine lost complete power and died at 60mph while in drive coasted out of fast lane to roll off hyw to exit and about 10 sec of coasting engine began running itself maybe by hyd pressure thru torque converter- decided to get back on hyw and it dies again about 2 minutes later just at next exit. Check engine lite came on and I turned around and made it home without towing. One item in freeze frame data odd is spark advance -59? And vehicle speed indicated 158mph I went to look at Evap canister and found bracket completely corroded which have one on order from bone yard today. The code for small and large vacuum leak will be addressed first - I would be grateful to anyone who has proper vacuum diagram for 2004 grand Cherokee with 6cy 4 liter engine and of course any finding from past experience - many thanks - Steven
Last edited by 04grand; 05-31-2017 at 08:34 AM.
