HELP! Severe acceleration lag

JARblue

Did they replace the CMC when they did the CSC? If not, that sounds like your problem.

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juld0zer

master cyl and clutch disc components were not replaced. but wouldnt a dud master feel sloppy when i first got the car back also? rather than re-emerge after a few weeks?

Mike,
Pedro and his mate suggested the throttle bodies were at fault. i followed that lead with no success, but i knocked over a different problem in doing so. I had an idle which needed a good dose of Viagra basically at the lights it would flop to 500rpm, rumble a bit then come up to normal. It wasnt 'rough' but it wasnt normal. On inspection i found what is in my opinion only minor carbon buildup. However, after cleaning (including removal from the engine and cleaning on a bench and actuating the flaps by hand) i realised how much carbon there actually was. There may not have been a lot but it was built up around critical areas, such as the edges of the butterfly plate and near where the butterfly plate rests on the walls of the throat. Because of this, i concluded it was carbon buildup around the idle/rest position of the butterfly causing an erratic idle due to carbon creating a sticky/tacky surface which catches the butterfly ever so slightly.

Both throttle bodies were not equally soiled. I cant remember which throttle body was the most soiled. I might also conclude at this point that the throttle rest relearn probably only considers bank 1's position and it tries to command the other throttle to be the same position at idle and so forth.

End result of cleaning the throttle bodies is a smooth idle but still lagging randomly. Give me a week and i'll report back with something else that im experimenting with. Ive become superstitious with this car.

I tried grounding the throttles to no avail also. that was just with a small wire bolted using one of the four allen bolts.

hang in there mate i've been battling this for over half a year now

P's_Z

Sorry to hear youre still having issue Juld0zer

However, its good to see you have not given up on this yet! After all this time, Nissan should just give you a new Z

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Zeta

juld0zer

problem is, it's very hot here in Australia (and it's only just spring!). we are seeing 38 degrees celsius ambients already. Because of the high ambients, it's getting harder to tell if it is actually the super-lag or just high IAT and high under hood temps causing knock to come on earlier, resulting in timing being pulled. I'd say it does feel more like a timing retarded sort of lag though

JARblue

Not necessarily... The CMC might have still been OK when the CSC was replaced, thus giving you the feeling of a repaired clutch system. However, the CMC is just as old as the original CSC was, and they are both fairly prone to failure. That's why the guys at Z1 and ZSpeed recommend replacing the CMC if you're replacing the CSC. I wouldn't be at all surprised if the CMC finally crapped out a few weeks after the CSC replacement - it certainly wouldn't be the first time its happened to someone on this forum. One guy was on the side of the road bleeding his clutch for over an hour with a buddy before determining that his CMC had failed, and that was just a week after he had the CSC replaced.

Also, the CSC failure will basically strand you - when it goes, it is typically sudden and complete failure. The CMC failure is usually a seal that might not fail completely when it starts to go. The pedal with a failing CMC may still be operable but will be pretty mushy. If this is what you are feeling, it's a pretty good indicator that your CMC is done. Luckily, the CMC is a much easier job (pretty cheap to pay someone and pretty easy to DIY).

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Ren425

Been a couple years I suppose since people have been on this thread.

Just curious and would like input from others about possible issue I am facing. I've owned the Z since the beginning, and this issue just came about.

Z (manual) drives like a champ up until the oil temps reach around 220-230. I live in LA and majority of the time is stop-go traffic.

As soon as the lights turn green, I get this hesitation from the Z between 0.8-3K RPM. It's most definitely hesitating/lag, if you're an enthusiast, you would know how your car responds to your driving, but in this case the car hesitates to accelerate. Once it reaches past 3.2-3.5K RPM, as if nothing has happened. It's a strange sensation.

I've read up on oil pressure for VVEL, brake switch, etc. was wondering if any of you would have further insight. No error codes, ECU was reset. I'd truly appreciate any insight if you have experienced the issue or know the cause and solution to this issue I am facing. Cheers

juld0zer

Get an oil cooler to begin with. Mine was a 2011 model with the factory oil/water heat exchanger and even in our hot Aussie summers it rarely went over 100*c in normal driving

Ren425

Thanks guys. Getting more insight. To break it down a bit further, the car feels as if it slips/hesitates between 0.8-3.2K RPM. I suppose an analogy is like your dog is on a leash and the you've got a grasp of your dog who wants to run free.

The catch is, I've already installed a oil cooler from 2 years back. Usually keeps my temps between 180-220 depending on how hot it is outside and how lead-footed I am. LA traffic definitely contributes to higher oil temps.

Do you guys still think it could be related to IAT, oil cooler or oil temp related? Heat soak is definitely a factor, but the problem only comes around when the Z reaches the 220-230F mark.

If it were the brake switch would it occur at any oil temp?
Could also be throttle response at that specific oil temp?

I'll have to see if the problem returns after like a quick stop on the side of the road or re-cranking. Further comments are appreciated, cheers guys.

SouthArk370Z

Sounds like the car is doing what it was designed to do - when temps get hot, the ECM starts pulling timing to protect the engine. A good oil cooler will help.

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