Running rough with my GTM SC...
 

Yes, it has been a while since I have checked in on the F.I. side of things on the forum.

I am having a weird problem with my Z right now. It seem when I start my car it feels like it is only running on 5 cylinders. After it warms up it seems to be fine but seems to stutter just a little bit when boost kicks in then it is fine again. The SC seems just fine, it seems more like an ignition problem.

I am thinking I either have a spark plug going, a coil going or maybe my cat is going as I am still on the stock cats.

While logging it seems that bank A is running a point higher than bank B. Now I regret only putting in one wideband sensor as the factory sensors are meh.

The car is not throwing any codes. I have not pulled the plugs yet to inspect them as I have my hands full with my race car build (240Z built to SCCA BSP Solo specs) and want to get that running ASAP. would have been done sooner but winter was brutal this year and it was too damn cold to work in the garage...

25,000 miles with no problems and now this... Pretty lucky I guess...

Any thoughts????

I'd swap the plugs first and go from there.

I would say plugs first, then maybe MAF cleaning/check.
After that it could be a number of things potentially but changing the plugs is a priority now.

Plus, plugs and Mafs are the cheapest possible solutions.

I have a set of one step cooler plugs (than the stock ones that are in it now, long story, thanks GTM) sitting on my work bench... Guess I will try that first.

K

When that happens, is there strong fuel smell coming out of the exhaust? You might want to give it an oil change due to so much unburnt fuel in the cylinders. This happened once in December. I also plan to get my spark plugs replaced this summer.

What plugs you guys currently running or want to?
I was quoted NGK and they are a fair price, half the price of the HKS equivalent.

In for updates as I am having a similar problem albeit much much worse.

I think there is a stronger exhaust smell. Not sure it is really a stronger fuel smell though.

I have HKS plugs on the workbench (Somewhere under all of the 240Z parts)

Where do you guys get the spark plugs from... All I have close to me is a NAPA

GTM sent me mine, after I finished the install of course...

Go to the dealer. Get a set of OEM GTR plugs.

Plugs are changed.

The engine is running a bit rich but there do not seem to be any obviously wet or overly fowled plugs, It was definitely time to change the plugs as they were way out of gap and the electrodes were not looking great.

As the car is running a bit rich I am betting one of the cats is done.

It really sounds exhaust related not sure if there is any way to check other than pulling the cats...

Guess it is time to go looking for some take off cats...

Turns out I had a dead injector. Sorry for the long wait on an update...

Check the corrections on both banks and see if they are the same . That would be a starting point. The bank that have a higher corrections will be the one that is having the issue .