It seems my car is starting to exhibit a issue and not sure what it could be. Was really bad today. I left work, so car was cold, started it up, and the idle went up to like 1200rpms or so.. Then the car started to shake and sound bad. I looked at the rpms and noticed the rpms were jumping between 1200 and 500rpms all erratic around that area. Then I revved it up a little, and it stopped. Anyone have a idea what is going on? I noticed this lately but not as bad as today. We had a pretty good temperature change today, and it's been raining the last few days.

 

Have seen a couple posts with similar problems. I'm sure you have to.

Have the dealer check it out. Has it thrown a CEL? Possible Crank or cam sensor issue seems to be the common problem.

 

bump.....Once the dealer see's my mods, they will blame them instantly.

 

usually how it works.

 

Call Uprev?? Reset ECU.. See if it will re tune for the new weather...

 

It didn't do it this morning. If it does it again, I will just unplug it overnight to see if it helps.

 

interesting solo..keep us posted.

 

Ya, it funny you say that because only as my friend house i get this weird problem. When i accurate in first girl i feel around 1,500 rpms a lose in power for a quick second.... is that just me or the car is really loosing power for a sec?

 

Sounds like you got the hesitation when taking off when cold. Some have experienced that part as well. I use too but that went away. Now this issue, but it hasn't done it again since that day. So I dunno.

 

hmm weird... and that only happens to me only when i leave my friends house when we were having wet days..

 

Dear Solo,

I have the same issue on my 07' HR with HFC, engine hesitations when cold start, did you solve this trouble, and advise me ? Thanks a lot !

I read that it should be a lean mixture issue ?

 

Solo sold his Z

 

Then, I hope that someone else can help me regarding this issue...

 

The issue solved by selling the car! :P

Actually I think it had to do with the mods. One of them at least. Maybe the HFCs or the UPREV tune. I had a cam position sensor fail on it later after this post before getting rid of the car. Replaced it, and it was good after that. Not sure if that may have been the issue or not.

 

funny i see this post again because im having the exact problems

 

it happened right after i got a re-tune on adding the intakes and y-pipe. could it be the intakes??

 

Thanks for the reply Solo, did the cell light on when your cam sensor failed ? With a specific DTC ?

Hope that someone can help to solve this issue !

 

It didn't completely fail. It was acting bad when on the track when I was pushing the car and I was loosing power and WOT. Wish it did, would have made things easier to figure out!

hellsoldier, Do you still have your cats? I think it seriously has something to do with the cats and tune combined. Not really sure. Try running in stock tune for a while since you can do that with UPREV to see how the car responds.

 

ya, i swiched it to the stock tune the nigh before and next morning it did again :? also, i took it up to uprev and after they trying they said i would have to leave it over night to see what causing it when it starts.

 

From my part it seems to be an S1 O2 issues, waiting for more information from my dealer...