I have 60k miles on my '05 and recently it has intermittent hard starting issues. I've tried looking for a pattern but it will do it regardless of fuel level, how long it sits or temperature. I changes the plugs and the wires without any difference. There is no problem with the car running just occasional hard starting. Any ideas? Thanks
ideas- maybe fuel pump and or fuel filter. If the pump is weak and can' hold pressure after power off. To diagnose, you need a fuel pressure gauge, but it should also have issues when accelerating hard. Does it start fine after just turning it off (when lots of pressure is still in the fuel line?). Clogged fuel filter doesn't really cause startup issues. Do you always prime the fuel pressure before turning the key all the way for the starter to kick in? What else is important at startup? Fuel, air, electricity. Air -maybe throttle body is gunky, and not enough air gets in at min throttle. If you can feel a difference with a slight throttle opening at startup, clean it. How about a stuck bypass valve, but I'd say that would make the car far less drivable, plus mpg would suck. I doubt the bypass valve would have this effect (if stuck closed), plus you'd have nasty mpg at normal driving. Battery is unlikely. You'd have other gremlins if there wasn't enough juice to fire up. Starter turns over, so you'd figure there's enough in the battery for a spark, which brings us back to the coil/wires/plugs and clean install of all that.
Thanks for all the thoughts fishmonger. All go for the coil first. Mileage is fine, power is fine, and no driving issues.
Easy stuff first Nick. Try that spare coil you have. If you haven't done the fuel filter it is time. Good luck.
Well the coil didn’t solve the problem. I’ll check the throttle body and clean it. Then get a fuel filter on order. I have let it prime before starting and didn’t make a difference. I’ll update after the cleaning.
Hard starting = starts but not instantly, right? If yes the fuel pressure test at the rail will tell you what you need to know about fuel pump and filter. I doubt changing those will solve the problem -- good maintenance items, they do fail, but again if pressure is good at the rail this is probably not it. Also, a starter that starts doesn't mean the starter is good. If it's not spinning up the motor quick enough its going to struggle to start. Heat kills these things and the proximity under the header doesn't help. I would also check your MAP and TMAP given the age and mileage. You can pull them out and clean them. Go through your fuses in the kick panel just to rule out - simple continuity test. Vacuum leaks could be a problem here too - the green gasket on the intake tube is notorious.
To answer the current questions. No I didn't disconnect the battery after changing the coil. The plugs looked fine. Not black, sooty or oily. I cleaned the throttle body and also found the intake boot a little loose. So far it seems like that may have solved the problem. Thank you everyone for your input. If the issue returns I'll post on this thread with new information.
New update. The problem started again as the temperature started going back up. I checked the fuel pressure. It was 48 psi, so with in spec. I have a new fuel filter on order. I read in a different place someone was having a similar problem. They finally changed the filter and the problem was solved. I'll update once the filter is in.
I had a similar problem way back. Recheck your fuel injector rail pressure w/ key in position 2. With @k-huevo's guidance, twas learned that initial R53 fuel pressure should be at around 52psi upon priming & shouls drop to 42 upon start & idle. If you're not getting those readings, the fuel rail pulse regulator diaphram may have gone. Other suspects for fuel distribution trouble: -Fuel Filter. Careful w/ installation. Improper sealing will cause No-Start. -Fuel Pressure Regulator by the in-tank Filter assembly -Fuel Rail Pulse Regulator -Cracked or split in-tank Fuel Pump lines. (I had this problem). Pump would keep pumping fuel back into the tank thru the split line. Lost pics when Photobucket killed hobo hosting. -Fuel Pump Another item to check besides the coilpack, leads & plugs would be the coolant temperature sensor. A faulty one would confuse your ECU. Hope you'd get it sorted soon! Sent from my SM-G950F using Tapatalk