2007 Suzuki Swift+ P0301 Shaking at Idle

[Arrakark]

Yesterday I replaced the timing belt, water pump, tensioner, and idler pulley. I found the process tedious. I didn't have a water pump pulley (Amazon lost my package??? That's a first), so I had to fabricate my own out of some aluminum.



While I know it's possible to do this without taking off the camshaft pulleys, I found it very difficult. Taking these off with an impact wrench (while locking them) threw alignment off, which took the better part of a day to get back in sync.



New water pump looks shiny.



I noticed that the lower timing belt cover was warped and interfered with the timing pulley (new and old pulley). This meant when I started the car for the first time again there was a lot of squealing and a plastic burning smell. After a short ride it went away though. I suspect the timing pulley melted/rubbed away about 1mm of the cover. Sadly, this did not fix the mixfire, but the car did run smoother still.

I decided to clean the injectors again. This time I fully took them off the fuel pipe. I was worried last time that I would break their clips and that's why I didn't take them off, but I figured that it was worth the risk. Turn out there was a layer of gunk on all of the injectors on their input! I'm not sure what had caused this; maybe a worn out hose or dirty enough gas, but I took some cleaner to it, and now the car drives fine!!

Wohoo!

I took it for a series of very long drives today and the car did not seem to be misfiring. Overall I estimated the fuel economy to be 9.55L/100km, which is a bit high, but probably normal for mostly city driving. Plus I'm not too sure about my estimate there.

All that's left to do is:

• Change the oil, power steering fluid, transmission fluid, and maybe the brake fluid
• Probably change the transmission filter
• Fix a snapped bolt in the valve cover (not me!!)
• Wipers
• Replace the front brakes
• Replace the serpentine belt; this one is super cracked
• Try my luck with repairing the clear coat with K2 and a good polish/fade into the old clear coat
• A good cleaning!

I'll keep updating this post. If anyone is also experiencing a similar misfire; make sure to clean the injectors!!