I searched can't find anything to help me at all. A little info on the car, it is a 98 Z24 5 speed with about 110k on the clock. The problem I am having is very irritating. The car has issues starting, but once it starts, will idle fine. It does this regardless of the operating temperature. As I said, it idles with no issues at all, but if I give it any more than half throttle sitting still, it hesitates badly. Less than half throttle and it will pick up RPM's no problem. The same happens while driving. I can be cruising at any speed and it runs smooth. If I try to accelerate with any more than half throttle, it has no power at all. Every now and then it will smooth out and pick up like it is supposed to.I am kind of leaning towards a bad cat, but I have no CEL and a bad cat would usually cause the issue all the time and not allow it to smooth out to my knowledge. Any info or help would be greatly appreciated.
i say try a new TPS (throttle position sensor)
I feel like taking a tinkle on an ecNOtec...
I already tried a TPS. Sorry forgot to mention that. I also smell fuel and it has been blowing black smoke. More signs of a cat, but I just want to get a second and third maybe even fourth opinion from people that have had these issues with these cars.
sounds like you're describing a misfire. could be bad coils.
Jon D wrote:sounds like you're describing a misfire. could be bad coils.
Yup, good description.
Open up your IDI cover off of the engine and look at the coil housing.
See if it's in good shaped with no clues of any arcing anywhere in or on the cover.
If so, replace it, and probably your coils too.
TPS was my first guess too but I've also seen this on the coil/ covers too. No spark ='s no fire which ='s gas in cylinder also meaning the smell of gas.
Good luck.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO! 
maybe an injector issue. Leaking is a possibility. maybe a short to the o2 sensor?
freelancer1988 wrote:maybe an injector issue. Leaking is a possibility. maybe a short to the o2 sensor?
Probably not. A fuel injector leaking into the cylinder would make it run like @!#$ at low throttle, but ok at high throttle. A short to the O2 sensor would throw a CEL, and the car would run like @!#$ at any time the coolant was over 160*F
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
Misnblu wrote:Jon D wrote:sounds like you're describing a misfire. could be bad coils.
Yup, good description.
Open up your IDI cover off of the engine and look at the coil housing.
See if it's in good shaped with no clues of any arcing anywhere in or on the cover.
If so, replace it, and probably your coils too.
TPS was my first guess too but I've also seen this on the coil/ covers too. No spark ='s no fire which ='s gas in cylinder also meaning the smell of gas.
Good luck.
First, thanks everyone for all the input.
My question to this is, wouldn't a miss throw a CEL? I thought it felt like a miss, but I also thought it would throw a CEL if it was a miss. Or maybe this car just wants to piss me off and not throw a CEL to at least give me a direction to go in.
I am gonna check out the coils and coil housing today. Luckily I work at a parts store, so I can play guess and check with alot of stuff.
Yes it usually would throw a misfire if there is one but depending on how often it happens within a period of time determines when the cel it thrown.
There are times where you have to have a third occurrence of the same type of fault for the cel to be indicated and what's happening with your situation may not be triggering the cel.
But do check the coil housing for sure as this won't take long and you'll know immediately when inspecting the housing if there's arcing going on.
Good luck.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!
Sounds kinda like my car did one of the times my FPR went bad.
"Oil Leak ? What oil Leak ? Oh, Thats Just The Sweat From All The HorsePower!!"
DSMskyline wrote:Sounds kinda like my car did one of the times my FPR went bad.
Fuel pressure regulator was another one of my thoughts. Doesn't look too hard to change on this motor.
Well I was finally able to get to checking the coils and the coil housing. There was one tiny sign of arcing. So I replaced all 4 plugs, boot, both coils, and the housing. Problem solved. Thanks everyone for your input.
