85_300original

1985 300zx Turbo. Two months ago I was driving and could not get it over 2500 rpms. When I finally eased it home it was not going over 2000 rpms. I have cleaned and tested just about every connection and replaced a lot as well. MAF TPS coils etc. I have researched this extensively and there are about 5-6 other posts I have found on the internet that have the same symptoms.

It was the TPS, but still having issues and is steadily getting colder and have been riding my motorcycles (not fun) haha. Now that I have narrowed it down more, please educate me all you can. I am not great with wiring and appreciate all the help i can get.

So i changed out the TPS and it worked for a day and it will now rev over 2500, but stutters ungodly amounts. Instead of it idling at 800 it goes in between 500 and 700. I unplug the MAF and it idles just fine, but of course hardly any response and moves as fast as a honda haha.

I have the the tps set from at 0.00 while at rest and it only goes to 13.5ish with very little throttle or wide open throttle. I'm so confused. Thanks a lot guys.


I am about to take a pipe bomb to it and then take it shooting

Anybody have ANY other ideas???? PLEASE HELP

rogerz

your tps settings make absolutely no sense. it is a switch and is either open or closed not 0.00 nor 13.5. the turbo cars have a speed limiter. My 85 went out and was somewhat as you described. clipped the purple wire on terminal 26 (check that on the schematic) and she went just fine. will the car rev over 2000 while sitting in the driveway, in nuetral? if it will rev while standing still but not when moving probably the speed limiter went **** up. that is what finally dawned on me after spending a lot of time on other stuff.

AZ-ZBum

Replace the MAF.

rogerz

he said he replaced the maf (maybe? hard to decipher when clear english not used). I too spent a lot of wasted effort chasing maf issues. It was the speed limiter.

85_300original

Should be about 0 to .10 or so volts with the throttle closed , the lower the better. 0 to .5 volts closed , 4.7 to 5 volts at WOT. That is from everything I've read

85_300original

Should be about 0 to .10 or so volts with the throttle closed , the lower the better. 0 to .5 volts closed , 4.7 to 5 volts at WOT. That is from everything I've read

rogerz

don't know what you are reading but it is a switch plain and simple. open or closed. there aren't any voltage readings that would be relevant. you can put it on a workbench and read it with a vom.

85_300original

those are the readings after i adjusted it. It's the manual. I thought it was supposed to be set by adjusting the the position of the sensor on the screw?

I am going to cut the hell out of that wire tomorrow. Is this the correct place?


TwinTurbo.NET: Nissan 300ZX forum - Z31 Voice Alert System Installation into Z32


Figure 4

85_300original

those are the readings after i adjusted it. It's the manual. I thought it was supposed to be set by adjusting the the position of the sensor on the screw?

I am going to cut the hell out of that wire tomorrow. Is this the correct place?


TwinTurbo.NET: Nissan 300ZX forum - Z31 Voice Alert System Installation into Z32


Figure 4

rogerz

bitchin betty got nothing to do with your problem. download the fsm and study the schematic. look at the ecu wiring. look for a wire that goes to speed limiter (turbo only). pretty sure it is pin 26 but check the schemataic.

85_300original

I know the voice doesn't that's why I said figure 4 in that post.