Hey guys, im new to this whole forum thing, im a volunteer firefighter and i work at jiffy lube, ive owned my z since last october, as a quick way to get to runs and i think theyre just beautiful, okay enough of the introduction, my z has been acting funny lately, when i start it up it will not let you give it full throttle for about 20 minutes, itll backfire out the exhaust and the intake, and will not go above 2,500 rpms, tried unplugging the maf and it gets worse, i just gave it a complete tune up (plug wires, plugs, fuel filter, new t-belt and water pump, and the motor was rebuilt woth new seals so i run full synthetic oil in it) any help? Ive glanced around at the forums and i cant really find a direct answer so i figured id make a post about it

 

Sounds engine temperature related the way you describe it - tho 20 minutes sounds too long to get up to temp. You should check the sensors sending temp info out to ECU and elsewhere. Cylinder head temp sensor (CHTS) etc. How is the idle while it's running bad? Also check the 2 solenoids on the air regulator. You are catching up with the maintenance that was not done by the PO.

 

Sorry its been so long, ive been real busy with my work schedule, and i recently found out the service recall to rewire the injectors hasnt been done and conveniently the dealership in my area cant get the part, also the wire to the fpr looks like someone took a lighter to it and the front drivers side injector looks all burnt, but the rest look brand new? I fixed some of the idle problem but every once in awhile under boost itll hesitate the BOOM! Huge backfire and it takes off like a bat outta hell

 

too bad you didn't replace the chts when you did the timing belt. often the cause of those type problems. unplug the O2 sensor see if that changes things. I wouldn't worry about the injector recall. if it hasn't burnt up by now probably won't. how do you know it wasn't done? here is some other stuff might help. (you do have the fsm -RIGHT)
Get your battery load tested. Be sure you have clean, tight corrosion free terminals on both ends of your battery cables. Be sure the ground (negative) cable goes to a bolt into the frame before going to the starter. grounding through the starter is not a reliable connection. Z's don't like low voltage. causes the electronics to act funny. it is possible to have enough amps to crank but not enough voltage to run the electronics. If you have one size fit all cheapo clamp on terminals they are a problem waiting to happen.

Clean the connectors for the maf or afm, ecu and tps. Deoxit by CAIG is probably the best connector cleaner on the market. spray with CorrosionX after cleaning and before putting together this will help prevent any further corrosion.

Replace outer tie rod ends, and ball joints. replace the bushings with poly (don't forget to lube them as directed unless you like squeaky things). New shocks. Get new boots for power steering. all those things will make you think you are driving a different car. doing them piece meal is a waste you won't see a great improvement until you do the complete job. You need to get the car realigned after messing with the front. Have your tires in good shape and rebalance. Rear bushings nice too but more work and you won't notice as great an improvement. Rear shocks also because if the fronts are gone so are the rears. if car squats when you jump on the gas the rears are gone. If you have the electro adjustable shocks they are DEFINITELY GONE.

If you are doing a turbo car shocks (electro adjust I think may be only on the turbos) then you need the adapter plates to fit modern shocks to the car. Easiest way is find an n/a at the junkyard and take the mounting plates. They may be available thru NAPA (listed) but I had the n/a plates.
check your fuel pressure and vacuum. vacuum leaks are the bane of the FI engine

 

Alright ill try that tomorrow, and i called the dealership and gave them the vin #, they said theres no record of any maintenance being done on the car through a dealership, battery is doing great, already had the maxima alternator on it when i got it , the shocks and bushings are shot, but ive got rust to deal with first, any tips on rust repair? Rear lower quarters are shot, along with the pinch welds and the spot underneath the pass. Seat, probably a spot about 3 in. round is rusted through the floorboard

 

And i do have the fsm, along with paperwork from the past owner who took it to firestone and dropped about 2 g's worth of work on it, its kinda to the point where whats good is REALLY good...but whats bad really needs attention soon

 

I think you said above that the fuel injector work/recall was not done on your Z. I recommend that you get it done. There were numerous instances of engine fires by the mid 90s so Nissan recalled all Z31s in '95. No need to roll the dice with that - and it's free. If it was done already, Nissan has your VIN on file.

Nissan will pay the dealer well so there isn't a reason for the dealer to turn you down unless he has no competent Z31 mechanics he can trust. I can put the Z31 recall(s) info below. You should find a dealer who will get the parts from Nissan and do the job. Takes less than a day to complete.

List of Z31 recalls: Nissan 300ZX Recalls - DealerRater

From Wiki: "On November 1, 1995 another recall (although not classified as a safety recall), all Z31s from 1984 - 1989 had dealers replace the entire fuel injection system, and changed the firing order, free of charge."

 

forget the injector recall. it was only because they started fires. the lack of dealer records means nothing. they weren't too up on that in the day. take a look at the wiring harness for injectors. if three on a side are wired with yellow wire in parallel it was dealer done. as I said if it hasn't burned up by now not gonna happen. the wiki quote is wrong. they just changed to a batch (each side separate) system.

battery great but ugly cables you gonna have trouble. I replaced both cables on my z31. go to a battery shop pretty cheap if you find a good one (hint NOT WalMart). I kept the ends that go to the starter because they are well made and had them crimp on new terminals. the ground strap (if original) will have a squarish copper plate crimped to the cable with a an M8 bolt going into the frame behind the battery between the terminal and the starter.

Rust buy a wire gun welder and learn to use it.

If still having problems replace the chts. do a google search there is a post on line on an easy way to do it.

 

A cold compression test would be a good place to start ..sounds very weak ..backfires out both valves ,you say . possibly slow/sticking valves ,timing related, bad cly. it's easy to do and rules out a major repair.

turbo seized ?

it may be a overfuel IC electric problem .. check the flashing lites but I like to know if the long block is solid 1st

if you want the recall and I would , ask when the DSM will be at that dealer (they have a schedual) and you want to talk to him about the recall / service bulletin
if he ,the service writer refuses get his name and call Nissan corp.

 

you're not in OZ anymore 86Tcoupe. you are in kansas Try to find data from nissan in the 80's is a very spotty thing

 

not sure what you mean Rogerz ...about the inj fire SB/recall ?
the recall is easy to tell if it has been done with the wiring change
the service writers make nada off warranty, is why they like to blow off those repairs .

70 sPL311
82T 280ZX gone ...weep .weep
86Tcoupe

 

take your vin to the dealer and ask about service history. Unles you bought it there you won't find much of anything. in the 80s they didn't have nationwide computer network. some dealers too lazy to input any data. Try to find your key numbers

 

I havent done a compression test on it yet but i did notice the turbo had minimal shaft play, like less than 1mm of movement, not too wise on turbos, only have had new aftermarket ones before the z, is that enough play to screw up the turbo? Ive got the day off tomorrow so im gonna throw in a new chts to see if it helps, cause it acts up when its cold and warmed up now, in between it runs just fine, these motors are a little more complicated than the four banger in my 92 gsx was lol

 

it sounds like your turbo is good as you say it runs normal for a while . probably compression too then . .040 is ok