Maxima: 99 5-Speed Fed Spec SE
ECU: A18-N04-Z84

Problems Leading Up to Failure:

1) Rough Idle
2) Higher Than Normal Idle
3) Idle would drop to 0 RPM and stall for no apparent reason.

Actions taken to fix issues 1-3.

a) Changed MAF (usual suspect) to a known good one from another 4th gen Maxima. I keep a couple of good spare MAFs on hand for times like this. No change after installation.

b) New Fuel Pressure Regulator and filter. Fuel pressure tests show 35 lbs (switch on) to 30 lbs after a few seconds.

c) EGR pipe and and temp sensor cleaned.

d) Throttle Body cleaned - I had my Nissan/Infiniti tech check and set the TPS.

e) New IACV - Standard Motor Part (SMP Intermotor OEM type). Idle improvement after installation. I kept the new IACV since the old IACV was showing wear on the stepper needle valve. The new IACV seemed to remedy the issue temporarily.

About 2 weeks later, I was driving it for a short drive and it died at a stop light -- will not restart.

It has good fuel pressure 30-35 lbs during start.

The injectors seem to all be all pulsing at once resulting in engine flooding.
While watching the fuel pressure testing gauge during a start attempt, there is one big 20 lb drop in pressure (injector pulse) for each engine revolution.
I can smell un-burned fuel from the exhaust. If I hold the accelerator open at WOT while trying to start is will almost start. It sounds like one cylinder is might be trying to fire.

Research indicates a failed ECU. I can send in my old ECU for diagnostics.

If the original ECU is repaired will the keys need to be reprogrammed due to the 99 model having NATS?

Does anyone have experience with ECU diagnostics and repair?

The ECU repair shops DEMAND the IACV and TPS be replaced before a reworked ECU can be warrantied. I can take back the IACV for exchange. I'll need to buy a new TPS.

Wouldn't good ECU failure diagnostics reveal the area that caused the problem thus indicating the part (e.g. IACV, TPS, PS Sensor, Electric Motor Mount for Automatics) so you're not just blasting a bunch of parts under the hood?

I found the following ECU repair service online. This ECU company will test an ECU for $35 which includes return shipment.

Foreign ECU Repair - Big Sandy TX - Specialize in ECU Nissan Infiniti Repair.
http://www.foreignecurepair.com/NissanRnR.htm

http://forums.maxima.org/4th-generat...p-success.html

Pictures of the ECU circuit board are listed below.

Top View



Bottom View

 

I'm not really good with electronics but have you truly determined the ECU is shot? Have you checked all the wiring going from the injectors to the ECU? Are there other electrical system failures that could indicate a bad ECU, Ie: theft system acting up, or other lights lit up that should go out after a second or two during Acc check? What codes di you have, I believe there is a code for a bad ECU, if I'm not mistaken?

 

My 99 ecu went bad, had the same symptoms. Repaced it with a 95 manual ecu and it works now. I didnt use a new iacv or tps.

 

The only code I found on the ECU after failure was a Cylinder 1 misfire. The CEL had not been on before failure.

No security codes or lights that stayed on.

The check engine light stays on when I turn the ignition switch on.

I reset the Cyl 1 misfire code. No change.

 

Replacing this 99 ECU with a 95 ECU would be a dream solution. No NATS and trips to the dealer for key reprogramming.

Did you need to modify anything to get your 99 to work with the 95 ECU?

Do you happen to have the ECU part number from your 95 ECU that I can use to purchase a 95 Manual ECU? I see there was a different part number for the SE as compared to a non SE for manuals. Any tips there?

 

ECU failure is not very common at all and should be the last think to loo at.
You need three things in place for the engine to run,
1) air
2) fuel
3') ignition

Have you figured out for sure which one your missing?

Check both crank shaft sensors.

 

My offroad racecar 98 auto was flooding big time and running but barely as it was pissing fuel big time. Only after doing the normally suggested stuff and some trial and error did I swap the ecu w/ a 95 manual and corrected the issues.

 

Normally you would get a check engine light with no codes or it could detect the malfunction with in itself

 

Maybe you have a bad grounding issue...has your clutch been changed recently? Check all the electrical connections that attach to the body or engine.

You can do a quick clean of ground connections by simply unscrewing then screwing things back in.

 

When I turn on the key, the CEL is on and will not go off.. I found a code for a Cyl 1 misfire though that does not indicate an issue that would keep the car from starting... I reset the codes via my OBDII reader, the CEL still stays on - no codes..

 

I will check this tonight.

Actually the clutch and engine was recently replaced.. New clutch and newer engine with 77,000 miles from a 95 model were installed about a month ago. For a few days after the new engine was installed, it had an issue with fast idle then low idle. It took the shop a few days to get the TPS and IACV all set with the new engine. I had the shop install a new IACV that seemed to cure the idle issue. My son had been driving the car for a couple of weeks. He had been bragging about how well it was running. So when I took the car for a drive up the street (I think I hit 3,000 RPM in 1st gear on that trip) when I stopped at the first red light -- it died never to be restarted..

 

Side note - I picked up an ECU from a wrecked early 96 (mfr. date 8/95) model, MT today on my way to work this morning. That 96 model car has ABS where my 99 se does not.
That car was definitely running when it was rear ended.. After I check for grounding issues, I will try installing that ECU to see what happens. I would really like to get away from the 99 model ECU if possible without changing the wiring harness..

 

Oh...check for spark.
And there is a member that did a re wire from a 99 to a 95/96 if your cali spec that may be a problem though. Is the security light solid lit with the key on or is it blinking? If your not getring any spark I would check the grounding system.

 

Fed spec.. No abnormal looking security lights that I recall.. I will check tonight.

 

Any good way to test for spark with COPs other to remove one and ground the plug to the engine (with it attached to the COP) and look for spark on the plug?

 

Nothing wrong with doing a quick check that way, just make sure the plug remains grounded. There is an inexpensive tester most parts stores have and it gives you a range that it should be in, kind of an easy way to tell if its good, bad or weak. With mine it was kind of a head scratcher because the non functional coil or coils would move randomly it was very strange.

 

Update 2/24/2014

1) Spark - I'm getting fire at all cylinders all following the same pattern. Today I bought an inline spark tester that I can put between the plug and the COP.

2) Anti-theft - The blinking light goes off as soon as I turn the key to the ACC or ON position. The light going off is consistent with my 99 I30.

3) CEL - Comes on as soon as I turn the ignition on and stays on. However, my OBDII scanner shows no stored codes.

4) Fuel - Fuel Pressure test 35 lbs for 3 seconds then drops to 30 lbs. Pressure drops 15 to 20 lbs all at once during a complete engine revolution.

5) ECU - For kicks I installed the ECU I bought today that is from a wrecked 96 (8/95) MT. Exactly same behavior as the 99 ECU -- including the CEL that will not go off.

6) Grounds - I need to get into the FSM to find the ground locations to verify connectivity tomorrow afternoon during daylight.

7) Smell - I smell unburned fuel under the hood and from the exhaust like the car is flooding.

8) Video - Check out the YouTube I recorded tonight and turn the volume up to hear how it tries to start -- but just doesn't make it. I got the same behavior with the 96 model ECU. It just wants to run so bad..

 

The reason I asked about the clutch is because the mating surfaces between the tranny and engine are supposed to be brushed down with like a metal brush so that when everything is put back together, the engine and tranny have good grounding connectivity. Something that mechanics forget to do sometimes.

You can override that issue by connecting a thick battery cable between the engine and tranny.

While you can use the FSM to find all the ground points, here are some of them off the top of my head;

On the passenger fender, around the windshield washer coolant filler neck, you should find 2 wires (not quite next to each other) screwed into the fender. That's them.

On the engine timing cover, above the belts, halfway to the top there should be another one.

On or around the front valve cover (the pretty thing labelled NISSAN 3000) there should be 2 right next to each other. Maybe you have to take the valve cover off to see them. These 2 ground the fuel injection wiring.

That's all I can remember. While you're at it, you may want to add a grounding kit. You can buy one or make your own, like I did. I just bought a bunch of battery cables and added connections all over the engine bay; engine to passenger fender, engine to firewall, tranny to drivers side fender etc.

Of course it goes without saying that you should do all this work with the battery dis-connected I got lazy once and didnt bother while doing electrical work and blew my bose system out. An hours investigation found that the Bose system protected itself and blew the fuse in the engine compartment. Thank god. Electrical issues are a nightmare to find and fix.

 

have u checked compression yet?

 

+1 for compression, check timing as well

 

I can check it again. However, the engine was idling smooth right up until it died. This newer engine has 77,000 miles on it. A compression test was run after the engine was installed roughly 3 weeks ago that yielded numbers to support a good run.

The original engine with 175,000 miles experienced an extreme loss of compression on cylinders 2 and 4 with minimal compression on cylinder 6. The mechanic thinks it jumped timing or had a catastrophic cylinder failure to cause the sudden compression loss. I have the engine in my garage to dissect to get to the root cause of that failure. I have a 99 I30 that is approaching 270,000 miles that runs great. Before the I30 I had a 95 Maxima SE 5-speed with over 160,000 miles that is still running great for the current owner. So I'm a huge VQ30DE fan and I care for the engines to last at least 300,000 miles.

After the failure happened to the original engine the starter would spin the engine much faster (without compression resistance) than it does today. It was like 2 or 3 of spark plugs had been removed.

The starter resistance from compression that can be seen and heard in the video is almost identical to my 99 I30...Except it starts after a few turns.

 

in case u missed njmax's suggestion earlier.

 

Researched the following threads for tonight's testing.

CPS
http://forums.maxima.org/5th-generat...-solution.html

CPS
http://forums.maxima.org/4th-generat...help-asap.html

Grounding
http://forums.maxima.org/5th-generat...not-start.html

 

Tonight I removed the engine compartment grounds, then gave them a polishing with sand paper and reconnected. I compared the grounds with the I30 and all are in the same locations. I also used some jumper cables to connect the engine exhaust manifold to the rear of the transmission. I use the type of cables that have copper plated teeth that bite into the metal to make contact. No change.

Next I swapped the crank position sensors with the 99 I30. The I30 started right up with with the CPS units from the Maxima. However, no starting for the Maxima with the CPS units from the I30.

Can a failed oil pressure switch cause a fail safe to keep the engine from running? Any relays that could be causing the problem? I've checked all fuses both inside the passenger compartment and in the engine compartment.

 

Man thats a bummer. This reminds me of when I did my friends EGR. After cleaning and putting back everything, the car would not start. I tried everything. I double checked all the connections and was convinced I missed nothing. So I walked away and left it for a day.

Next day I came back to the car and tried to start it again, only this time I immediately floored it WOT. The engine sputtered and slowly came back to life. I drove it for 30 minutes and it settled down to normal. Car has been running fine ever since.

What I think happened in my situation is that the ECU forgot everything it knew about the engine and was "re-introduced" to the old motor as if new.

Like I said, after that the car was fine.....it's been about a year now.....no hiccups whatsover.

Maybe something in this tale would apply to you. Who knows?

Hope this helps

 

Your video sounds like either the timing being off or a plugged converter.

 

I tend to agree. Since swapping the crank position sensors with the running I30 yielded no change, as preventative maintenance items I'm planning to replace the cam position sensor, the coolant temp sensors (since those were moved from the original engine that I learned after purchase had been run hot several times by the previous owner), and figure out a way to disconnect the cats to start it.

Back in the 70s, I was driving a GM car (472 V8) down the interstate at ~65 MPH when the car started missing and backfiring through the carburetor like the timing chain had jumped. I shut it down to keep from blowing the engine I thought. It turned out the large muffler baffle had collapsed that blocked the exhaust. That was a relief.. I can see how a blocked exhaust can keep one from starting..

 

Pulling a precat o2 then try cranking would be the quick an easy way to rule out the cats or blockage downstream.

 

PROGRESS - IT NOW RUNS! Albeit a little rough but it started up tonight.

On the way home from work, I stopped at a local parts store and picked up some Standard Motor Parts (SMP) BWD/Intermotor sensors. I've had good luck with BWD Intermotor parts for other sensors. Yes, SMP BWD Intermotor parts do cost more than other brands, but I've never had a bad experience. So I had a coupon for 40% off and I picked up a new camshaft position sensor, and the two coolant temperature sensors located on the coolant pipe between the cylinder banks for $69 and change plus tax.

1st - When we changed the camshaft position sensor, it would almost start, like it was trying to run on one cylinder. I could see improvement but it just didn't want to run.

2nd - I changed the two coolant sensors and then it started. Yea!

3rd - Now that it runs, I put on the OBDII scanner and found no codes with no CEL lights.

It is running a little rough at the moment. When I try to adjust the IACV, it seems to be ignoring any adjustments I make. It feels like classic bad MAF idle roughness. I'm going to swap the MAF between the Max and the I30 to see what happens. It was running better last week, but at least it is now running again.

Side Note: The Max got all new NGK/NTK new O2 sensors roughly 3,000 miles ago. Though with the engine swap, it got new NGK plugs, IACV, KS, KS harness, fuel pressure regulator, new hoses (vacuum and water), new water pump, front motor mount, rack boots, gaskets, and a new clutch.

 

So you're saying it was a combination of crank and coolant sensors which shut your car down? No plugged cat or anything? Bizarre

Good to hear you got it running.

 

Still to solve for is the rough idle issue. I'm still scratching my head over that one.

Should I send the ECU out to TX for testing to verify all circuits are working properly?

 

Any issues with the idle goto the IACV. Your ECU is fine. Check for good IACV connectivity and any potential vacuum leaks.

 

This morning I ran a compression test. I pulled all plugs and used a couple squirts of ATF to wet the cylinders.

Here are the numbers below.

Cyls - LBS

1 - 160
3 - 195
5 - 210

2 - 180
4 - 180
6 - 215

I noticed I cannot feel the IACV stepper motor click or move when I turn the ignition switch on. I ohm tested the pink plug connection and found 19.8 ohms. I ohm tested another old IACV from the 99 I30 I keep as a spare and found the pink plug connections to produce a 20 ohm reading.

Update: I ohm tested the original IACV pink plug connections and got a 21.8 ohm reading. I'll check the stepper motor now.

When the replacement engine (from the wrecked Max) was initially tested after start, Cyl 1 had a 100 LBS reading with others at 120 to 140. So driving the engine for a couple of weeks allowed the numbers to climb higher. Though Cyl 1 is still the lowest one in the group.

 

After re-installing the clean IACV (the original) I could hear the stepper motor moving when the ignition is turned on. I had the MAF unplugged and it started right up for a minute then quickly died. Naturally, there was a lot of smoke coming from the exhaust as it was burning the ATF I used during this morning's wet compression test. That is to be expected. I reset the codes, and tried to start it again without success.

After it died this afternoon, the Security Light is now on when I try to start it. I got a CEL code for the MAF being unplugged, and a new code P1336 (crankshaft position sensor). The crank position sensors were swapped a couple of days ago with working sensors from the I30. So I'm beginning to think that code is bogus or ECU problem related.

Here's a picture of me trying to start it (dash lights) with the security code that now stays on when I try to start it.

Note: I tried using the 96 model ECU and received the same security code. It still would not start and shows the same behavior with either the 99 or 96 model ECU.

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Maybe the theft system became activated? On the old GM caliber I had theft system acting up was the stare of complete ECU failure. But you swapped the ECU with a Knowen good one...So maybe a falut in the wiring, for the ECU or possibly just the theft system itself.

 

I think there is something outside of the ECU that triggers immobilization. The security light stays on regardless if I'm using the 96 or 99 ECU. I tried the procedure to reset security without any luck. I think think I will send the ECU off and get it tested for $35 then go from there. If the ECU comes back as good, then I guess I will have it towed to the dealer as I'm running out of ideas here. If the ECU was found to have a problem, then that explains it..

Long term I would like to make the pin changes to be able to run the 96 ECU -- but I want to do that with a running car as I'm chasing too many gremlins with this one in its current state.

 

Yeah I think sending it off for testing Isn't a bad idea, since its only $35.
LOL, I know what you mean about them gremlins. I deal with those as well as body rust from the salty and snowy roads

 

Installing the 96 ECU does nothing without making the pin changes, It did probably trigger the Immobilzer though.
There was a post about someone bypassing the fuel pump relay when he was immobilized. I cant find the post though. From my notes he removed the relay and connected the black/white wire to the black/yellow wire. You might want to try this with the 99 ECU installed.

 

The immobilizer tripped when we were trying to start it with the 99 ECU. It had briefly started with the 99 ECU after changing the IACV. Later I tried the 96 ECU. We had the door open on it when we were trying to start it before the immobilizer tripped using the 99 ECU.

Is there a rule for 3 unsuccessful start attempts with the door open trips the immobilizer?

 

Check the wiring for the CPS by the oil pan, my 99 max did this problem ur having after i changed my oil one time, turns out the wire for the CPS was corroded very bad due to excessive oil over time