Husker

I need some help. My dad has an 87 Maxima and it just won't run right. When you start it up it runs rough and if you floor the gas pedal it will go to 2,000 rpm and just hold won't go up past it. If you gently give it gas it will climb up further but it is still very unresponsive. After it has warmed up a bit it will run good enough that you can drive it but it is not very responsive and seems to be lacking a lot of power. The following have been replaced on it and none seem to be having an effect. Head Temp Sensor, HTS wiring harness, spark plugs, wires, cap, rotor, Mass Air Flow Sensor(From Auto Zone). And the computer never gives any trouble codes. Thanks for any help!

MaxWgn

iTrader: (1)

Only things I've ever seen or heard of doing that are the MAF and the ECU. Just a note, the rebuilt MAF could still be faulty. Since oyu have a new one, check some local wrecking yards, and see if they have one pulled...one for an 84-89 300ZX non-turbo(turbo may work - not sure), or 85-88 maxima. If they do, see if they'll let you try it out, if you're able to get the car to the yard. There could also be some corrosion on the elec connector for the MAF.

If you want to try out ECU's, you can use one from the same cars listed above, except if you use an ECU from a 300ZX, you have to make sure it was not turbo'd...those ECU's are not interchangable.

Husker

Will the MAF fit without modification from a 300zx? I have access to an 87 non-turbo and an 84 turbo.

maximase86

iTrader: (24)

The 87 non-turbo should be a direct bolt on, considering they are the same motor. The 84 turbo on the other hand many not work because the motor is forced induction.

S

Husker

Thanks I'll try and swap them tonight and see if that fixes the problem.

dr.disc

There is no difference between the Z31 (1st gen. 300ZX) AFM s, turbo or non-turbo. An AFM is what you are calling a MAF.

MaxWgn

iTrader: (1)

Mechanically, there is no differnece...

however, on the Maxima's, on the input side of the MAF, it bolts directly to the stock air box, and hence is flat, with mounting holes - the type that requires a MAF adapter to install a CAI, etc...

The Z31 MAF has the 3" "nipple" on both ends, negating the need for MAF adapter...that is the only difference I have been able to find on them...if you're still running the stock air box, and the Z31 MAF fixes the problem, then you can just buy a simple cone filter, with a 3" inlet, and clamp it directly to the MAF. This will give the a hot air intake...but it will flow more air that the stock box...but I
wouldn't jump on that until you know the Z31 MAF works, and if you plan on keeping it in the Maxima...

Good luck...

Husker

Well I swamped the computers from the 87nt first and that was the problem. Thanks for the for the help. Now what should I be paying for the "new" computer, is a junk yard the best place to go? I had a computer from an 84 turbo but I can't find it anymore I think I gave it away when I sold my 84 turbo. I wounder if I could trade a good auto transmission from an 84turbo for an ECU, anybody have any luck with junkyard making trades.

maximase86

iTrader: (24)

I would just use the 87 NA ECU, since you already have it, put it to use.

S

Husker

Well that was a thought except the 87NA is my brothers car and he wouldn't like the fact that is car doesn't run anymore. I guess I should have been a little clearer in my post the 87NA and 84T 300zx's are both good running cars so I knew the parts were good for testing. My family is Nissan crazy 00 maxima se, 02 maxima se, 87 maxima, 87na 300zx, 84TAE 300zx, and I at one point owned two 84T 300ZX's one was totaled and I took it's engine/transmission, and interier and installed it into the other one(that was fun got $3000 and the car back then spent $1200 on the body of the other one bought a ton of tools and a few parts and then sold it in running condition 1 1/2 later for $1250, but at least I got a lot of tools)

maximase86

iTrader: (24)

Oh gotcha....yeah, salvage yards are the best bet.

S

Joe-280Z

uhm, my car was running rough as well.. so your ECU was the issue? heh.. mine.. well it isnt solved yet, but so far I know the O2 sensor was dead to the world.. It was burining really rich, so rich that the cat melted... or at least turned really, really, bright red. heh.. Sense I live in an area that dosent require emmisions testing, ill just cut the Soab off and weld a pipe to connect the sides... or hell hollow it out so I dont get fined and all that bull-$hit if a cop starts peeping around my ride...

dr.disc

Lots of times, running rich is a problem with the CHTS (cylinder head temperature sensor), or its wiring harness. The CHTS and harness section can be bought online from Courtesy Nissan in Texas.

There is an issue regarding 86 300ZX 02 sensors, that may apply to 87 Maximas, the issue being lots of parts houses are supplying the wrong 02 sensor, making the car run rich. This issue exists for 87 200SX SE vehicles as well, the engine in them is the same as the 86 300ZX na, with minor exceptions to plumbing for the engine. They have the small O2 sensor, at least some of them do.

I own an 84 300ZX 50th Anniversary Edition turbo coupe, an 84 Slicktop 300ZX non-turbo coupe, an 84 300ZX engine (converted to Maxima and taken back out), an 85 Maxima, an 85 Maxima and 87 Maxima power train (no body just the engines and transaxles), and an 87 and an 88 300ZX non-turbo coupe.

Mostly, I drive the 85 Maxima, I like it the best for all-around driving. The other cars are usually in some stage of a project.

I mention owning them, because it gives me a basis for comparison between the model years and types of cars that came with the VG30 engine. The 87 Maxima and the 87 200SX SE have the same type O2 sensor on them, at least mine do, and the 87 300ZX and 88 300ZX have another. The 84s have a large one on it. I am not making statements regarding what the factory did, but just passing along observations about my fleet. I don't have FSMs for any of them, just the Haynes and (worse, much worse) the Chilton manuals.

Having the wrong type 02 sensor with a given ECU can make a car run badly, and rich condition is a prime symptom.

Since so many of our cars (and the 300ZXs) have a problem with breaking exhaust manifolds, especially the side with the )02 sensor, some cars are showing up with the wrong O2 sensor on them, because they had a broken exhaust manifold replaced and the incorrect 02 sensor was installed along with it because it was already on there.

This might be something for you to check out, besides the CHTS. I would put in a new CHTS and harness first. Its near the coolant intake for the engine, in front of and below the fuel pressure regulator, by the obnoxious little elbow hose that is so hard to change out.

There is no real reason to cut off a cat unless it is clogged up, even if you don't have to pass emissions testing.