Hi all My z32 vert is fickle. Spent $$$$$ on her and mechanic has replaced nearly everything but still cant pinpoint this issue. Prob something so minor we're missing it..... When slowing down the revs will jump up and down making an er urgh er urgh noise. Revs stay below 750 while doing it. When i go to take off there is no power even with foot flat to floor. She putt putts til she decides to go.... She doesnt do either all the time and some days will only do the rev thing not the putt putt. Other days its just the putt putt from take off. Occasionally she does neither. She will do it cold or hot, on a downhill on an uphill on a flat. Depends entirely what mood she is in. She is a 92 full convertible with 130k non turbo. Auto electrician has also checked wiring with no faults. Serviced every 6 months. Have replaced timing kit twice. She always did the rev thing on occasion but then I sold her and bought her back 15mths later to discover this new putt putt thing. She did less than 4k from the time I sold her to when I bought her back. I love her which is why I bought her back but oh my god she's doing mine and my mechanics head in. My mechanic only charges for parts not labour so I'm not getting ripped off either. My next thought is should I just replace the engine and go tt. Please any thoughts???? Welcome all responses even if already been there done that!
What trans does it have? If it's an auto that's stuffed in a strange way it could be labouring the engine?
Check TPS voltage. TwinTurboTim on youtube does a video on how to do it. Should be 0.45V at idle. Make sure throttle plates are adjusted correctly too. If you/mechanic has an ECUtalk (or similar) cable to check what the ECU is doing and seeing, might help a lot. I'd also be willing to bet it's a vacuum leak. Could also be CAS or MAF sensors or wiring intermittently faulty.
There was a great write up about poor idle and stumble hesitation a few years ago. I actual printed it out and it is in my shed somewhere. I did it just in case I every needed it. I have no idea where it came from. Maybe look in the tech section or google for it. I will have a look and see if I can find it. It was very well set out with where to start and in plain English. For starters do the basic like checking all connectors for fit and corrosion. Also look up the tech section for a plan of where all the vacuum lines need to run and follow them and make sure exactly they are right. I did the deletes years ago and my car behaved weird similar to what you describe. It took me a while but after going over the vacuum line several times I found 2 that were swapped for position. This surprised me as I thought at the time all vacuum lines would do the same thing. If I find the write up I will put up the email address for you. I think I just found it under stumble and hesitation in the tech section. Have a look Cheers Dave
