new owner, car will idle, but wont rev, just spudders

[nismo528]

First off let me say this site is great, I have found alot of useful information and I may even be asking/describing a problem that has already been answered, if so i am sorry.

Ok, here is the deal, I bought a 1990 300zx 5 speed ttop n/a wreck.... I worked in body shops for 12 years so buying a front end damaged car is not a huge concern to me, the car starts up and idles, a little rough, but not too bad. I believe it has alot to do with the fact the front end is pretty smashed and the air box is missing, so there are no air filters on it. I do also have some experience with nissans, I had a 89 stanza with a ca20e in it several years ago, so I do know some of the quirks that nissans have when things are not just right. My questions and concern is even though it runs and idles if i press on the gas peddle it starts shuddering really bad and does not rev past 2k - 2500 rpm. I do see some vacuum lines that are disconnected and rotten on it, one of which i plugged to see if it made a difference as I have not located exactly where it is supposed to go for now (i am still trying to get it away from the guys house that i bought it from) my question is does this sound like a vacuum issue or bigger?

Thanks!

[nismo528]

any suggestions or ideas what might be causing this would be greatly appreciated. This car and motor are completely new to me, and looking at things on this forum as well as others, i am now second guessing myself for buying this car, even though i only paid $400 for it. http://s1256.beta.photobucket.com/user/ ... c.jpg.html Thanks again

S/N: I think I may have figured out one of the contributing factors, I was not sure where the MAF sensor was located, apparently it sits just behind the bumper, being as the air box is missing and there is nothing connected to the intake Y pipe there, I would say that is one of my problems! Please look through my picture album, I will be adding more tomorrow and as I go along with this build. If anyone sees thing that I am missing from my car, please let me know, like I said I am new to these cars and I bought a wreck with missing parts. Thank you for having pictures of other builds on here that I was able to reference and figure out some of the things I am missing.

[t.mcginley.jr]

Ok so most of us wouldn't have bought that car but since you know all about body work that kind of makes up for it. From the pictures, the engine itself looks to be in good condition minus the front intake parts and the radiator area looks pretty bent.

Your problem sounds like a combination of a vacuum leak or leaks (plural) and a missing MAF sensor. Normally you have that intake Y pipe, then the MAF sensor, then the airbox/filter. It's not usually too hard finding a MAF online. You can skip the airbox and just put a cone-style filter on. You should also replace all the vacuum lines. The PCV valves and hoses could be shot too. Take some more pictures of the engine if you can, specifically the areas where you say there's vacuum lines going nowhere. Even without the MAF sensor, the ecu should attempt to run the engine just with the TPS, but that might be toast too, or badly miscalibrated.

One thing you should note with these cars is that all of the electrical connection are prone to corrosion. So it's not uncommon to pull connectors and see some green crap on the metal inside. Some light filing/cleaning and dielectric grease fixes this usually.

Post back with updates

[nismo528]

I got the car to the shop this evening, got the hood and what was left of the front bumper cover off. also picked up a maf sensor from a maxima with a 3.0 in it today from the junk yard, now i just need to get some piping and hook it up, hopefully it will work or at least clean it up enough that i will know it will fix the problem with a new correct maf sensor. or has anyone used one off of a 3.0 maxima and it work correctly? If so I will keep it and use it since it only cost me $30 vs. $150+ for the correct 300zx one. I did not have a chance to take pictures of it yet, but i will start documenting the repair soon.

I wanted to also say thank you t.mcginley.jr for your input and help so far, I am sure I will have plenty more questions for you as I go along with this project.

[t.mcginley.jr]

No problem man that's what the forum is here for

I'm pretty sure the MAF for the maxima won't work on the z32, almost positive it's the wrong size. If you need used (and sometimes new) parts you can check out the Z32 Classifieds section. Here are a couple of threads that might have a MAF for you (you'll have to ask):

parting-out-1990-n-a-300zx-t561414.html

parting-out-multiple-z-s-cincinnati-ohio-t535360.html

1993-n-a-part-out-t521088.html

Also ebay and craigslist aren't bad places to look for some parts. Just don't buy really important parts from ebay like timing belts and head gaskets.

Keep posting back with updates... it's good to hear someone saving an otherwise wrecked Z