I changed my spark plugs n coils, Changed air filter, Cleaned the throttle body and im still getting hesitation during acceleration. Cold starts sounds crazy and uphill even worse. When it happens my service engine soon starts flashing. IDK what the problem is. I got a schedule appointment wit the dealer 2morrow to check whats the problem. Any ideas??? please help. 2004/g35coupe/mt

 

any mods

 

Sounds like either timing is off or you are losing compression and getting a miss under load. I havent really gotten into our engine electrical yet but you should be able to pull the codes and figure out which cylinder heads are miss firing. double check your wires make sure you have the correct order(i dont even think our cars have wires the coils just plug into the spark plug, but this is a common mistake). our cars have timing chains and not belts so im not sure how the timing would be an issue. mileage? mods? need a little more info to properly help out. im guessing you are over 100k seeing as you did plugs and coils. how bad is the hesitation? does the car ever reach full power under a load? driving the car probably isnt the best thing for it, beware of detonation especially if youre getting a miss. go over the electrical and make sure everything is plugged in and secure, the most likely cause is a short somewhere. check the coils make sure they are all completely pressed in and tight to the head.


edit: dirty injectors not putting fuel into the cylinder could also be the culprit. Run some marvel mystery oil in the engine and through some lucas in the gas tank at your next fill up too. You should only run the Marvel for about 1k miles, wait until you are close to an oil change and then drop in a quart. The marvel is very high detergent so i would hold back a bit when its in (dont rev over 5k you are 6mt so that shouldnt be too hard.)

 

I have a 2007 G35 S and I'm experiencing the same problem. The dealer in San Antonio told me that it's the rear timing cover seals that have gone out which allows for a slow oil leak. I was told that this repair will cost nearly $2 to $3,000. I was also told that Nissan/Infiniti are aware of this issue and has since redesigned the rear timing cover seals. Have you been able to fix yours?