Hey Guys:

I'm really struggling with my Z right now. I just replaced the plugs, wires, opti-spark, fuel filter, waterpump, injectors, maf, and performed my normal "out-of-storage" maintenance (cleaned my slp air intake, changed oil, etc.). However, my car will very sparatically hesitate and "chug". It idles fine and sounds fine. Sometimes it drives 100%, but then it will have those times when it chugs like that. During those times, if I just continue driving, I drive through it and the car will continue to run fine. I'm super confused. I brought it to my mechanic and he wasn't able to find the problem either. He said the fuel pressure was good and he thought it felt like a fuel problem. He then let me know that it would only cost me more money by leaving the car with him, as he would just be throwing parts at it to troubleshoot the problem. He advised me to try these things on my own, as I already replaced the opti in my garage. SO, I'm looking for any help/suggestions......

**No check engine light or anything either

 

Sounds like the transmission module that shifts the trans,but I'm an idiot.It keeps me from going insane.Hope this helps.

 

I have a T56 - 6 speed trans

 

You didn't state other mods etc, but I'll assume it to be nearly stock or simple bolt-ons etc. Is there a chance your cat. converter is clogged or partially clogged but not throwing a code? Is it more a hesitation up hills? Also what grade gas are you running? Aside from the tranny, can't think of anything else offhand, but hopefully it's a cheap fix.

 

I only run 93 Octane Premium fuel. You were correct in assuming the car is mostly stock. All I have done is an SLP cold air intake. It seems, after driving the car more, that if I let the car sit and warm up before it drive it, then its better. But it normally hesitates a little bit yet. However, if I just start the car up and drive it, it runs like crap for quite awhile, even after my car gets to normal operating temps. ANY OTHER IDEAS? **I always thought that a cat would get worse after the car warmed up?

Thanks for the help guys.