the-sleeper-z31 Posted May 14, 2009 Share Posted May 14, 2009 my 86 300zx will not rev up past 2800 or so RPM! I dont get it ive drained the computer and ive manually cleared the codes. nothing is working this time.... it was this way when i got it. i let it sit without a battery in it fir a month. started her up one day to move her, and it revved up just fine........... and now the problems back. does anybody know a z31 genius??????? Quote Link to comment Share on other sites More sharing options...
Jehannum Posted May 14, 2009 Share Posted May 14, 2009 For ECCS cars, that usually means that the ECU isn't receiving signal from the MAS. Quote Link to comment Share on other sites More sharing options...
the-sleeper-z31 Posted May 14, 2009 Author Share Posted May 14, 2009 I was thinking that too, there is some faulty electrical work under the hood. like the plug to the TPS is missing and they stuck the wires in there in some random order hoping the would be right. cant find a diagram that tells me enough info to make sure they are good... Quote Link to comment Share on other sites More sharing options...
DeleriousZ Posted May 15, 2009 Share Posted May 15, 2009 http://www.xenonz31.com/reference you'll find the factory service manual there, it has all the wiring diagrams you need. you can also run the ecu trouble codes, there is a procedure on xenon's site as well, that should give you some idea of what the problem is. Quote Link to comment Share on other sites More sharing options...
zylephone Posted June 1, 2009 Share Posted June 1, 2009 i used to have an 86 and it did the same thing, i replaced the maf sensor and it did it. they are pretty cheap too Quote Link to comment Share on other sites More sharing options...
Megatherion Posted June 1, 2009 Share Posted June 1, 2009 http://www.xenonz31.com/reference you'll find the factory service manual there, it has all the wiring diagrams you need. you can also run the ecu trouble codes, there is a procedure on xenon's site as well, that should give you some idea of what the problem is. Thanks for posting this. I'll need this soon! Quote Link to comment Share on other sites More sharing options...
Zerocell5688 Posted September 23, 2009 Share Posted September 23, 2009 super useful guides here! i'll need them soon! ~J Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted September 23, 2009 Share Posted September 23, 2009 unplug the tps (or I guess pull the wires out) and see if that cures the problem. Then check the maf per the fsm. You don't really need to pull it out of the car. Pull the rubber boot back so you can see the connections. Push pins in the appropriate lettered connector then with some japanese jumpers and a VOM you can get the readings. You need to run 12v to pin E with the engine off to get one reading. Then start the engine (pull the 12v wire first) and you get the reading specified when you blow air thru the device. If everything else checks out you might want to cut the purple wire at pin 29 at the ecu. This is the overspeed limiter. Spent two weeks on an 85T swapping ecus, mafs, tracing wires to no avail. After much cussing and head banging found that to be the problem. Also you can exceed 137 mph if that fixes things. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.