Glad to be a part of the new forum... however unfortunately for this reason:
-After completing a timing belt change on 09 EXL the motor has a misfire and runs horribly at idle. After idling for approximately 1 minute the check engine light flashes on the dash and runs smoother but not to its potential.
The van had no misfires or check engine lights prior to new timing belt installation and ran well.
The following codes pulled are P0301 P0302 P0303 P0300.
The codes indicate a misfire in cylinders 1,2,3 and random misfire. My first concern was that the rear cam gear (firewall side) was off a tooth. I'll note now that this isn't my first timing belt job on a honda. I've successfully installed timing belts on 2 other honda v6 j series engines (early 2000 models) and also countless 4 cylinder engines including rebuilds. I'm doing this for a family member and it's their most practical vehicle to haul the kids around.
So I went back and triple checked all timing gear alignments. Everything was spot on. All replacement parts are genuine Honda, which includes water pump, timing belt and tensioner, and spark plugs.
Same results when starting. I swapped coil packs from the other cylinder bank that weren't causing misfires to rule out igntion or coil pack failure. Checked spark and fuel on cylinders 1-3. Compression test yielded relatively even numbers across all 6 cylinders.
When doing the install the rear bank cam gear DID slip from its tdc alignment mark ONLY when the timing belt was OFF the engine. My grave concern, was that I potentially bent a valve(s) on cylinder 1 when the piston was at tdc. At tdc, pistons 2 and 3 are sunken down enough in the cylinders that the valves would not contact.
After exhausting other options, I wanted to confirm whether any valves were bent. I pulled the rear bank head. Head and valves appeared to be in good condition. The valves had no evidence or marks contacting the pistons which I've seen on other engines. I took the head to a reputable machinist to double check and he confirmed there were no bent valves. The head was cleaned and he reseated and did a valve job on all 12 valves.
I installed the reconditioned head and used a new oem honda headgasket, did a valve adjustment to spec, and reinstalled the timing belt spot on. Even had a friend, former Honda dealer mechanic, come over and verify timing marks. Unfortunately it still runs the same, rough idle for around a minute until the check engine light flashes and increases the revs to around 2k rpms. Same misfire codes as before. I went back and ensured all wiring clips were fully seated on the injector housings. Same results.
I'd greatly appreciate any advice or curious if any of you had a similar scenario. My main priority is to get this van running back the way it was. There was one post listed on this forum with similar circumstances but the original poster never updated the thread with the outcome. I will surely keep this updated with the fix to aid others in the future.
Any possible issues with VCM? The other j series engines I've worked on before did not have VCM. I'm not too familiar with which cylinders it controls but wonder if it's possibility it could cause an problem.
Thank you all