hi guys having a little problem finaly got my tt zed back on the road and after driving it for 3 weeks i come to a set of lights and went to take off for some reason it wont rev over 2 - 2500 rpm and splutters(even less revs when under load). it idle s perfect but nothing over that i was told to try the AFM as it would go into limp mod,which i borrow one but still no differace.Also tried the self diagnostics and got 55 which is no error. Any idea s
<2500RPM Sounds AFM related... are you sure the donor AFM wasn't faulty too? AFM's can be faulty and not throw codes. Also check the electrical connectors to the AFM. Dirty/weak connections could explain why 2 AFM's didn't work... Also consider PTU...
seconded im pretty sure its AFM related check the connection and make sure its tight because if that metal clip bends then it doesnt hold properly
Is it all the time or when it is getting warm? We have a similar problem with my friends car. It is fine when it is cold, but suddenly when it gets warm it is doing the same thing. It is a 300zx tt auto. He told me it happen after he got another engine installed for 2 years ago, and never run probably after that. He had to mechanic several times, but they couldn't fix it, so now he try to sell it for cheap. It is a bit sad, so we hope we can work it out. I will follow the thread and see if I can use it to something as well. Christian
There are only so many causes PTU, AFM & CAS (possibly) are most likely contenders for the below scenario. Also electrical connectors for all equally important to check, clean & retension...
You say it's fine below 2500ish? I'd say check your throttle pipes and where they join. A big boost leak would do exactly what you're describing. Especially if it happened from nothing, a pipe or clamp could finally have worked itself loose.
I've got this same problem and i have replaced the following bits with known good ones AFM Fuel Damper CAS New Plugs Mine will clear up when i get over 4500rpm though ... got me stumped I wouldnt imagine that if it were teh PTU that the problem would clear up in the higher RPM range
actually when i started it from cold it seamed to rev past that but taking it around the block she started again once she was get warm. the AFM i borrow was on a working car and the plug was clean and a tight fit,new plugs were installed.
This fixed it for me. Exactly what happened to me. Throttle pipes came off a bit and i got nothing above 2500. Pushed it back on and did the clamp up tighter and it was fine.
Hey there... If I say that the Cat light comes on everytime it does that. Does that make it more clear if it is the PTU, AFM or the CAS?? Hopefully I have time to swap play with it tomorrow.
I'm fairly sure the cat isn't related. Find the connectors for the three systems Zed4Life mentioned and take the connectors off. They will possibly be coated with green corrosion. I just took off my IAA and the connectors were so bad they wouldn't conduct electricity. No wonder my idle was stuffed!!! This will help you: http://www.plantbonz.com/cars/photoguide/index.html The AFM is also known as the MAS. The connectors should mostly pull out with some gentle screwdriver work. Use a very small file and get all the corrosion off and then spray them with some WD-40/RP7/Inox etc. etc. (Though if you have electrical contact leaner or brake cleaner that is the best). Put them back together and if you want, spray with some silicon or similar to save them from getting corroded in the future (or pack them with grease, but that's messy)
Thanks a lot... Hope I can get it fixed tomorrow. I thought swapping my friend PTU, CAS and AFM with mine one by one, would show which one he need to replace, but I can't find my PTU so I can't swap that. Must have been removed, but I don't know to where. I have been looking three times now and its gone...
You have to have a PTU somewhere. Check these, each shows a different place it might have been relocated: http://tech.aus300zx.com/moveptu/movingptu.htm (in front of battery near fuse box) http://tech.aus300zx.com/ptu/pturelocation.htm (near passenger side throttle body) http://tech.aus300zx.com/moveptu/movingptu_option3.htm (under nose near air filter)
Ages? I've had idle problems for like 4 days now haha. I'm hoping this will fix it, just about ready to attach the IAA now. Before was the transmission. But that is fantastic with the new valve body. I get wheel chirp changing from 1st to 2nd. Never had an auto do that to me before
Yeah I have been looking all those places, and I tried to follow the cables coming out near the batteri, but none of them ends in a PTU. A few cables going down behind the engine so maybe they have moved it down underneath the car somewhere.
