99zx2

iTrader: (3)

Hi, all! New to the 5th gen, but not to the Nissan family (have a 97 i30)

Picked this one up for $500 today. Didn't want to stay running, per seller's description. Body is fair (got some minor dents and front-end needs some work), engine has an oil leak coming from somewhere in the back (allegedly a vc leak), but overall a decent buy, I guess.

Now to the problem. I've read up on this prior to buying the car, and a lot of the threads on here dealt with a bad maf. I got it in the garage and unhooked the maf. Turned her over and she barely idled (around 400rpm). Plug it back in, and gee, she is up and idling on her own (rpm were climbing up and down, though).

Tore into the intake system and here's what I've found (sorry about the huge pics):

https://810920ae4e86fe71a7b1846d7178...621_162657.jpg

https://810920ae4e86fe71a7b1846d7178...621_162700.jpg

I take it, this will induce unmetered air into the crankcase. I will go ahead and try to find this elbow at a local jy soon.

Also, how is the maf supposed to be clocked on this one? Here's how it was hooked up:

https://810920ae4e86fe71a7b1846d7178...621_164809.jpg

https://810920ae4e86fe71a7b1846d7178...621_164817.jpg

Does this intake pipe suppose to have a clamp on it? It sure didn't and was really loose:
https://810920ae4e86fe71a7b1846d7178...621_165941.jpg

The only wet spot I could locate in the rear so far. Haven't jacked it up yet.

https://810920ae4e86fe71a7b1846d7178...621_163240.jpg

https://810920ae4e86fe71a7b1846d7178...621_163306.jpg

Short on time, but will def. add more details later. Any input is appreciated!

99zx2

iTrader: (3)

Apparently, I didn't notice the maf to resonator coupler missing...

https://810920ae4e86fe71a7b1846d7178...622_230533.jpg

Anyone has one or knows of an aftermarket/stock replacement?

Thanks!

DennisMik

iTrader: (2)

It looks like a lot of the running problems may be fixed by getting everything air tight on the throttle body air intake.

Do the bolts that hold the MAF onto the air filter box tighten? Or are they cross threaded and stripped? The bolt sticking up may not be the original and maybe isn't metric. However, this isn't really a problem as this is on the inlet end. Any air that may get in gets metered by the MAF. The only objection is that any air that leaks in isn't filtered.

The duct pipe that is loose, is that way from the factory.
https://810920ae4e86fe71a7b1846d7178...621_165941.jpg
I am not sure exactly what purpose it serves, but I think it may be to drain any water that might get sucked in when driving in the rain so the air filter stays dry.

The one thing that concerns me is that when you got the car running, the idle moved up and down. Worst case, this could be a shorted IACV (Intake Air Control Valve). This tends to burn up the STA509A chips in the ECU. You didn't mention anything about the check engine light, but the IACV would be a P0505 code.

99zx2

iTrader: (3)

Thanks, Dennis! You always seem to be on the right track!

I'm waiting for yet another piece (the maf to resonator coupler) to come in, and then I'll try to fire her up again.

I've checked the codes and it had several:

p1165 - i think that valve was disconnected at the time
one for the maf - when I disconnected it and fired her up
p1320 - this and 1165 were still pending, so we'll see if they come back after everything is back together. Might need to start eying the coils!

What was/is the deal with the iacv frying ecus?

99zx2

iTrader: (3)

Latest development(s).

Got the rubber insulator in and put everything together. It starts, but then the idle jumps from 2000-3500 or so repeatedly. PO allegedly replaced the iacv... Here's the vid:

https://810920ae4e86fe71a7b1846d7178...624_193921.mp4

Also, some kind of noise is emitting from under the hood with the key "on":

https://810920ae4e86fe71a7b1846d7178...624_193900.mp4

I think pressing the gas pedal stops that noise.

Also, took a crappy picture of where the oil leak seems to be originating (you can see a silhouette of the drip right next to the half shaft on the left). Seems to sit right around the bolt area of the rear exhaust manifold. VC?

https://810920ae4e86fe71a7b1846d7178...624_195016.jpg

Any help is appreciated! I did quickly skim thru the idle relearn and even tried it, but couldn't get the cel to flash. The car wasn't at operating temp. Not sure how to even get it to it in this condition lol

99zx2

iTrader: (3)

Took the pcm out (what a *****). Does this look fried to you?

https://810920ae4e86fe71a7b1846d7178...624_213425.jpg

https://810920ae4e86fe71a7b1846d7178...624_213437.jpg

https://810920ae4e86fe71a7b1846d7178...624_213448.jpg

https://810920ae4e86fe71a7b1846d7178...624_213657.jpg

Also. Disconnected the tps (brown plug) while it was revving up and down, the rpm just shot up into the red zone (full throttle). Strange.

cornholio

iTrader: (1)

i'm no expert, but it looks fried to me

99zx2

iTrader: (3)

hmm. disconnected the iacv and it was still revving up and down.

cornholio

iTrader: (1)

new ecm and iacv is the cure i believe, or part of it

DennisMik

iTrader: (2)

You have a burned up ECU. There are 3 parts of the car that will do this. The IACV and 2 motor mounts. When I listened to the noise video/sound clip, I thought maybe the motor mounts.

You might want to unplug the motor mounts at least as a test.

maximasicilian123

Do the motor mounts and iacv cause problems for an 02 also?

cornholio

iTrader: (1)

im 95% sure, but read this thread for more info: http://forums.maxima.org/5th-generat...d-seconds.html

tons of additional info (almost too much to read through) if you search iacv or p0505. the motor mount thing i read was pretty common also, not sure how that translates to idle issues other than the computer is toast

maximasicilian123

Is the iacv whats eliminated when installing the nwp plate? I wanna avoid this issue. How do I know if mounts are electric? Figure I'm change them while im doing the clutch.

cornholio

iTrader: (1)

iacv is attached to the bottom of the throttle body, nwp plate blocks EGR port iirc, so iacv shouldnt be eliminated

electric mounts only are only for models with auto trans. if you're manual there should be nothing to worry about

CS_AR

A few months ago I sent my troubled 99 SE 5MT to foreignecurepair (FECUR) in Big Sandy TX for diagnostics. FECUR tested the ECU and found it to be bad. They located a replacement (exact part number) for $250 and provided an 18 month warranty. Since then FECUR offers a 5 year replacement warranty for an additional $39. I'm satisfied with the service I received from FECUR.

http://www.foreignecurepair.com/

Last week I ordered a VAG OBD2 409.1 cable for $13 that will allow me to use Nissan Data Scan 2 (NDS2) to reprogram NATS keys on my 99 models.

I remember seeing a post on the 5th gen section where someone used NDS2 to resync keys.

Last weekend I picked up another ECU at Pick-n-Pull from a wrecked 99 SE 5MT for approximately $40 to use for testing a NATS resync with NDS2. That was the first 99 model 5MT that I've seen in a salvage yard. So I thought I had better grab the ECU just to have a spare for testing.

When the VAG 409.01 cable arrives (hopefully next week) I aim to test NDS2 on one of my 99 models for posting instructions on how a 4th gen owner can reset NATS using NDS2. I don't see Blatz selling the cables any longer. So I ordered mine from eBay. Note that I cannot recommend the eBay seller until the cable arrives and I have a successful test.

Do you have a salvage yard in your area where you can get a replacement ECU? If your Max is a 5MT your selection may be limited.

Links of interest:

http://forums.maxima.org/all-motor/6...-nvis-tip.html

http://www.nissandatascan.com/

Also you can search the ORG for Keyword: 5523 to find threads on this subject.

99zx2

iTrader: (3)

Thanks, Dennis. I will try that. Looks like I might be parting/junking this thing, as I don't feel like messing with the new ecm. Will I be able to at least start it with the new ecm? (w/o key reprogram)
At 220k it seems to have potential, but when all is fixed and done, I could've just bought it for $1500 w/o these issues lol Only spent $560 so far, but it will need at least $800-1000 more at this point. Not sure, if it's worth it.

It's an auto. Thanks for the tips!

99zx2

iTrader: (3)

Could I just purchase the chip and have it soldered in? The strange thing is that it didn't react any different when I disconnected the iacv, like it wasn't even there to begin with. I will take the tb off in the mean-time and see if I can find anything there.

CS_AR

I've read about owners fixing it DIY. If you are good with a soldering gun then why not?

99zx2

iTrader: (3)

That's what I am going to do. Just ordered a new chip off ebay. Will disconnect the mounts, per Dennis' recommendation later tonight, and also check all the vacuum hoses and fuses under the hood as well. Ohm out the iacv and see if it has the gasket on it. Is it 22 Ohms to be in spec? Should the iacv cycle with the key "on"?

cornholio

iTrader: (1)

i don't really know what's strange about it- if the iacv is shorted and the ecm is shorted it means the iacv is either not working correctly or not working at all. if it's not working at all wouldn't you expect the same when you disconnect it?

from what i've read about this the 3 most cost effective solutions are:
a) buy the chip and solder to ecm by yourself, buy new iacv
b) send your ecm to be repaired ($100-150?), buy new iacv
c) find junkyard ecm, gamble with junkyard iacv/buy new iacv, pay to have car towed to dealership and pay to have keys matched to new ecm

99zx2

iTrader: (3)

strange, because it's supposed to be new. i will need to do some diagnostics with my multimeter, before doing any of the 3 above.

cornholio

iTrader: (1)

i must have missed the part about the new iacv. i know replacing the ecm and using a bad iacv can short the ecm again, i do not remember if using a new iacv with a damaged ecm can hurt the iacv. i'm sure it's been answered in another thread.

fwiw when i replaced my iacv all multimeter diagnostic checked out ok. it is worth noting my failure was not the typical coolant caused short that took the ecm with it. i guess i lucked out.

good luck

99zx2

iTrader: (3)

thanks, man. about to start on it shortly.

99zx2

iTrader: (3)

I'll be damned...

https://810920ae4e86fe71a7b1846d7178...625_193107.jpg

https://810920ae4e86fe71a7b1846d7178...625_193059.jpg

It's alive! Though idles around 1.5k and is still a bit jumpy. What is the proper relearn procedure for these? 02-03 instructions don't seem to work. Can't get the cel to start blinking...

cornholio

iTrader: (1)

PRE-CONDITIONING
NFEC0642S02
Before performing “Idle Air Volume Learning”, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
+ Battery voltage: More than 12.9V (At idle)
+ Engine coolant temperature: 70 - 99°C (158 - 210°F)
+ PNP switch: ON
+ Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.
+ Cooling fan motor: Not operating
+ Steering wheel: Neutral (Straight-ahead position)
+ Vehicle speed: Stopped
+ Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until “FLUID
TEMP SE” in “DATA MONITOR” mode of “A/T” system indicates
less than 0.9V.
For A/T models without CONSULT-II and M/T models, drive
vehicle for 10 minutes.

Without CONSULT-II
1. Turn ignition switch “ON” and wait at least 1 second.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PRE-CONDITIONING”
(previously mentioned) are in good order.
5. Turn ignition switch “OFF” and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Disconnect throttle position sensor harness connector (brown),
then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the
result will be incomplete. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.

ITEM SPECIFICATION
Idle speed VQ20DE M/T: 675±50 rpm
A/T: 700±50 rpm (in “P” or “N” position)
VQ30DE M/T: 625±50 rpm
A/T: 700±50 rpm (in “P” or “N” position)
Ignition timing VQ20DE M/T: 9°±5° BTDC
A/T: 9°±5° BTDC (in “P” or ”N” position)
VQ30DE M/T: 15°±5° BTDC
A/T: 15°±5° BTDC (in “P” or “N” position)
NOTE:
If idle air volume learning cannot be performed successfully,
proceed as follows:
1) Check that throttle valve is fully closed.
2) Check PCV valve operation.
3) Check that downstream of throttle valve is free from air
leakage.
4) Adjust closed throttle position switch and reset memory.
(Refer to Basic Inspection, EC-90.)
5) When the above three items check out OK, engine component
parts and their installation condition are questionable.
Check and eliminate the cause of the problem.
It is useful to perform “TROUBLE DIAGNOSIS — SPECIFICATION
VALUE”, EC-122.
6) If any of the following conditions occur after the engine
has started, eliminate the cause of the problem and perform
“Idle air volume learning” all over again:
+ Engine stalls.
+ Erroneous idle.
+ Blown fuses related to the IACV-AAC valve system.

99zx2

iTrader: (3)

Where are the said fuses? I've seen these instructions before, but not sure if the car meets "all" of them, as it is still in the garage, though I got the fans to come on today, as it was warming up. Don't want to idle it for too long, as the oil is leaking directly on the exhaust manifold. Might need to fix that first, before messing with this any further. Can't wait to take the UIM off...

99zx2

iTrader: (3)

This thing keeps on giving. Took it out for a wash and here's the new development:

https://810920ae4e86fe71a7b1846d7178...626_191228.mp4

I don't think it has Mercon in the p/s system, but I could care less at this point. Part-out thread coming shortly.