Well since you had to unplug the sensors to swap them around then its possible that the code was triggered during the process. Especially if you forgot to plug it in, tried to start, then realized that it was unplugged, or swapped them around with the key on. Check the wiring anyway just in case its not an accidental code trip.

 

UPDATE 3/7

Foreign ECU Repair tested the ECU and found a bad processor chip. I appreciate the quick diagnosis turnaround.

Foreign ECU is ordering a replacement ECU for shipment to me next week. Since I've got to take the car to the dealer to get the immobilizer reset, I will send the keys to get them reprogrammed to match the new ECU.

I can do some pinout testing (per FSM manual EC section) this weekend while I wait for the new ECU to arrive.

Is there any chance power surges from running a Kenwood subwoofer amp (without a capacitor) could have shortened the life of the original ECU?

Since this is not an automatic with the electric motor mount or water cooled IACV like the 5th gen, are there any possible culprits to rule out before I install the new ECU?


http://www.foreignecurepair.com/NissanRnR.htm

 

Heat or water I am certain is what killed mine and on a dsm I own the iac is a very common killer that why I simply leave it unplugged.

 

Tonight I received the old bad ECU and a certified replacement from Foreign ECU Repair. Since the processor had failed on the old ECU they had no reason to keep it. The replacement has been tested and sealed for the 18 month warranty. The cost was $250 - delivered to my door.

Since I will need to get the immobilizer reset and keys reprogrammed to match the new ECU, I will be getting AAA to tow it to my local Nissan Dealer.

So far I am impressed with Foreign ECU quickly locating and sending a replacement with the exact part number.

http://www.foreignecurepair.com/NissanRnR.htm

Picture below.

 

Today the dealership installed the replacement ECU. The service tech called this afternoon to say they are able to start it and make it run for a short time by pulling the fuel pump fuse. No kidding! He said the car is experiencing some extreme flooding. If they plug in the fuel pump fuse it builds up enough pressure to start the car but they need to immediately pull the fuse to keep it from flooding to keep it running a short while longer.

This seems like is the original flooding problem that occurred before the engine lost compression on 2 cylinders. However the issue went away for a couple of weeks after we installed the new engine. I'm starting to think the reason I lost 2 cylinders was due to hydro-lock from too much fuel. I sure don't want to lose this new engine to hydro-lock from too much fuel.

The fuel pressure regulator is new. The fuel pressure test held steady at 30 lbs with a spike up to 35 lbs when I would turn on the key.

Has anyone seen an extreme flooding problem like this one where removing the fuel pump fuse allows the car to run?

 

Kinked or plugged fuel return line will do that.

 

Update:

1) Dealer installed replacement ECU and reprogrammed the keys to match. The car was starting but flooding.

2) Dealer checks return fuel line for blockage and found none. The fuel pressure regulator is new. Dealer reports no issue with fuel pressure or return line obstruction.

3) Dealer set (using Consult) the TPS and IACV and other adjustments that allow it to run. Still hard to start and doesn't run good.

4) Dealer used Consult to run a power balance test. Power balance test revealed a problem with CYL #5. Coils were swapped to rule out a bad coil. Problem with #5 still persists after swapping coils. Before car was towed to the dealer, I ran a spark test on all cylinders where all were found to be firing to rule out a wiring or coil issue.

Dealer also noted the hard to start and ruff running issue could be from a bad cat. However, no bad cat codes have been seen on this car. If I receive any further news about a bad cat, I will request dealer remove the upstream O2 sensor and run the car to verify the bad cat.

Note I performed a wet compression test before the car was hauled to the dealer and found the following results:

1 - 160
3 - 195
5 - 210

2 - 180
4 - 180
6 - 215


5) I requested the dealer ohm test the injectors to determine if a bad injector for CYL #5 is the issue. I am waiting for the dealer to test and provide results. This is spring break week so I doubt I will get any news until next week. The dealer acts like they are not interested in working on it because it is requiring "out of the norm diagnosis" to resolve.

 

There's no such thing as a bad cat code. The only way the car should notice is for the ECU to compare the O2 sensor readings before and after the cat, but even that is iffy at best. There was a thread on here where someone found a proper method to test a bad cat by testing for back pressure....can't find it at the moment. But that's pretty much the only way to detect it. Well, other than visually inspecting it too.

 

Testing the resistance of the injector is only half testing it. It checks to see if the solenoid is capable of opening the valve to let the fuel through.

This leaves the mechanical half of the injector as an unknown. Cracked/broken pintle caps can create a fuel leak around the o-ring, not to mention the possibility of a bad o-ring. This stuff requires the injector to be removed for a visual inspection.

Gotta love the dealer...

 

I was under the impression it's 43.5psi

 

Dennis - I'm with ya on the injector ohm testing as only 1/2 of the picture. Naturally the one that needs an inspection is under the plenum..

Most of my Nissan troubleshooting experience is with my VH45DE (G50) where I had two injectors fail within in a week. I found a couple of injectors with resistance readings in the 20s. I have a Consult like testing program for ODBI named ECUTalk where I was able confirm the failed injectors with the power balance test. The injectors in that 91 were the older rotary style that I replaced with a set of new BWD black dots. If one bad injector is found in the bank under the plenum, I will most like replace on that bank to keep a similar spray pattern and some balance going with the O2 sensor. It could be the pentile caps need to be replaced. I asked the guy who did the engine swap to look for that and I had him install new injector grommets when the rails were moved from the original engine to the replacement.

Unfortunately, I don't have a program like ECUTalk or Consult for ODBII. Coupled with needing to get the keys reprogrammed, I've been at the dealer's mercy.

Quicky - I agree the fuel pressure looked about 10 lbs too low. My 91 G50 with the original factory fuel pump will give 43.5 lbs then drop about 4 lbs to this day. I don't have enough experience with a DSC4 running at 30-35 lbs to know if it would cause all the headaches I'm seeing. Usually on a G50, the pump works good enough to keep the car running but it starts making a loud hum to warn you it is on the way out.. If you don't replace it quickly, it burns out the FPCU and then the car stops running. Most of us G50 guys keep a spare FPCU around in the event the fuel pump has a surprise failure.

Is fuel pressure in the 30-35 range a cause for some of the symptoms. I haven't heard any humming noises. Does a DSC4 have a FPCU that can be fried by a failing fuel pump?

No P0420 or P0430 failing catalyst codes have surfaced. One thing that happened though, is the rear exhaust pipe (suitcase muffler area) was replaced with a large flow pipe about a week or two before all hell started breaking loose on this car.. I've read where an improperly installed exhaust pipe can cause problems with the flex pipe or allow a cat to become broken. I feel certain the guy who changed the engine (Infiniti trained master tech) would have caught it.. But he could have been bust that day. I think if I start having cat trouble, I'll reach out to the WarpSpeed guys up the road and try something from their shop.

If the dealer says the injectors test out or continue to have no clue as to the cause, I think I'll drive the car home and continue discussing ideas with you guys to find a solution. Their efforts seem to be half *** at best. They don't realize how many new Altima customers I've sent them over the past couple of years. That may stop..

We really like the way DSC4 5-speed runs and drives. This is a particularly nice one that has a new suspension and almost everything new under the hood. We were hoping to have some AutoX fun with it this year. With buying it and all the money spent over the past 18 months I figure I've got in the neighborhood of $5,500 in this one at this point.

Quicky - Here's a picture of the "low water mark" fuel pressure test from my G50. I agree 30 seems low. I'm just not familiar enough the the DSC4 to know what to expect. Also, I used the same gauge to test.



Dennis - Here the BWD black dots installed in G50 rails before installation.



After installation..



:
So I'm out of my comfort zone with this DSC4 and looking for ideas.

 

I was just asking because nobody else said anything. Either the guage is bad or something is wrong. What kind of fuel filter do you have?

 

New NISSAN OEM fuel filter. They cost a little more but I like the way they are built.

Does a weak fuel pump start to go by having low pressure? Would consult identify a weak fuel pump?

 

The picture of the G50 fuel rails & injectors - pretty! The installed picture is a little disappointing because you can't see that much of them.

I have no experience with a bad fuel pump on the Maxima. But Consult cannot identify a weak fuel pump because there are no sensors in the car for fuel pressure.

According to the FSM, the fuel pressure should be 34 psi at idle, no other pressure/rpm figures given.

The fuel injectors on the 3rd gen Maximas were somewhat of a problem as they got older. Normal resistance was 12 or 14 ohms, but that would start climbing. Usually you could keep using them until the resistance got over 50 ohms and they would cause a miss. I had a pair on my 94 that got up to 75 ohms before they died. But the 4th gen fuel injectors aren't a problem like the 3rd gen had.

Changing subjects to the ECU and the security light, when you put a 95 to 98 ECU into a 99, the NATS and the chipped key system don't exist. There is nothing in the ECU for NATS, so that would not keep the car from starting.

However, as Maxima_Joe said earlier in this thread, the wire assignments in the connector for the 99 are different than the other years. You need to swap wires to use a 96 ECU. I know there have been a couple of posts with the wire swaps.

 

OK I eat humble pie......was half right

 

Like you said earlier the fuel pump tends to get noisy as a symptom of going to soon fail. That's what happened to a previous Altima I owned.

In my present I30 I believe that my fuel pump is going. It's not noisy, but a strange performance issue, coupled with the fact that it looked like pretty much none of the fuel related items (FPR, Fuel filter etc) had been changed during its 150K miles lifetime.

The strange performance issue is that if I'm in 4th gear in a performance oriented mood, accelerating strongly up a hill, I feel a strange lightness in power delivery, like it could do more, but doesn't. Other than that, the car seems fine. I assume that accelerating strongly up a hill in 4th gear would have a tendency to push the fuel pump near its limit.Once I do replace the fuel pump I'll know for certain, but it's not critical for me as yet.

 

I stopped by the dealer late yesterday before closing time. The are still stumped. It is hard to start and doesn't idle smooth. So we're back to the original symptom that was present right after the engine was swapped.

As a side note, a new water pump was installed in the replacement engine while it was out of the car. I don't know if the shop owner or his trainee actually installed the new pump. I've read on here about someone letting the timing chain or gear slip by one notch when installing a new water pump. When they started the car it ran bad until they re-positioned the timing gears.

I know the shop owner knows how to keep the chain from slipping as he built a tool for changing TC tensioners. I had him change the tensioner on the I30 a couple of years back. However, if he let his trainee change the water pump, he may have let the chain or a cam slip.

 

The dealer still can't figure it out.. They report low compression - though the mechanic is not there. They say is started up and ran fine after reprogramming the ECU for about 5 minutes and then quit. I've been out at least $800 with the dealer so far. They want $1,400 to pull the timing cover to check the timing line up. If they can get it running on Monday, I'm bringing it home. I may need to have it towed if they can't get it started. I'm about to throw in the towel.

 

GOOD NEWS! I finally figured it out. Three or more major lessons learned:

1) Do not trust a dealer with your 4DSC. That is unless you are ready send it to the salvage yard. More on this later in the post.

2) A gasoline engine is basically an air pump. I read about that on this forum and it spurred thoughts to try something tonight that revealed a major problem.

3) If you are buying a used engine, perform a "leak down test" at the salvage yard or before you have the replacement installed. No doubt a compression test will reveal a weak cylinder issue. However, when the engine is in a wrecked car in a salvage yard, or sitting on a shop floor without a starter to run a compression test, a simple "leak down test" can be used to reveal intake valve issues, exhaust valve issue, and piston/ring issues.

Earlier this week the dealer reported the car would not run. No codes were being reported to Consult. A Consult power balance test revealed no power from cylinder #5. Cylinders 1 and 2 had 90 LBS of compression and combined with Cyl #5 was preventing the car from running. The dealer indicated the replacement ECU was installed, keys reprogrammed, and the car started and ran for 5 minutes before it stopped running. They said it took running the starter 10 minutes to get the car to finally start again and that would quickly flood out and die. The said engine needed to be replaced and that low compression was the problem. That was the same tune they sang back in November with the previous engine. I knew their diagnosis was basically BS when all they could talk about was 90 lbs of compression for Cyls 1 and 2. The mechanic that installed the engine reported 100 lbs (under spec) as a concern but it did not keep the car from running. My wet compression test found Cyls 1 and 2 to be at 160 and 180 LBS. I requested the dealer run a full "system shakedown" to look for any fuel, electrical, or exhaust restriction problems. I paid for all that anyway.

When I went to pay for the car, the dealer called and suggested that I get a tow truck to take the Maxima away because it would not run. A asked them if they solved the CEL code issue (with no codes being reported) and they indicated no codes were present and if the CEL light was on and that was most likely caused by the low compression issue.

Today I paid a tow truck $65 to bring the Max home. I figured with help from Maxima.org, I could figure out the issue and make a lot more progress in my driveway. If something was so wrong with the Max that it would never run again, at least I have one helluva parts car to use for the next DSC4.

This afternoon when I met the wrecker driver at the dealership, we tried to start the car and found the battery was almost completely dead and the check engine light was still on. At that point, I realized I have been dealing with people who are lying, stupid, or both.. I grew up working at an imported car dealership, so I've seen it from the other side of the counter and know how the game was played. The only time a customer really got a fair shake on a car that required some type of "out of the norm" diagnostic service activity was when the owner or general manager actually feared the customer could have a negative impact on their financial well being. Ha!

So I got the car to my house and put it up on jack stands. Next I removed the upstream O2 sensors and let them hang loose. After that I hooked up the jumper cables to the Q45 and proceeded to start up the Maxima. It took about 2 minutes of running the starter at WOT for it to finally fire up. I could tell the engine was starting to hit on a couple of cylinders so I just kept the throttle open to clear whatever had been flooding or choking from the dealer's attempts to make the car run. I let it run in the driveway for a good 30 minutes while changing RPM as I could tell a big part of the problem was starting to clear up. I shut down the engine and it started up with minimal cranking. I still have a smooth idle issue that truly may be due to low compression. I'm not doubting that is an issue. It just wasn't enough to keep the car from starting and running. At this point, my gut instinct is telling me there may be an issue with intake valves that may not be closing/seating properly or I have some weak coils or both. I took some zip ties and secured the O2 sensors so they would not be damaged while I took the car for a test drive.

Although it was loud from the exhaust escaping from the O2 sensor holes, I drove the car for about 5 miles in varying traffic conditions and I was surprised at how much power it has. It was almost like driving the first 95 Max 5-speed again.

Now I need to get suggestions for some performance cats.

Also, I would like to check the valve clearance and run a "leak down test" on this engine before I pull the heads and send them out to the machine shop to get a full R&R service.

Now that the Max is running and driving again, I'm excited about taking it to the next level.

I will post new thread in the "All Engine" section to discuss alternatives for the smooth idle issue as I may find an opportunity for providing a some "how to" documents as I work to get the Max running at optimal performance.

As a side note, the replacement ECU appears to be working without issue. I did get a couple of cylinder misfires this afternoon that triggered a CEL code. Those are easy items I can research without keeping this thread open. Also, I was able to reset the codes found from the dealer and and clear the orange CEL as normal. No further strange ECU immobilization issues to report.

 

I was curious...why do you call it a DSC4 and not a 4DSC?

Good to know. Also more interesting is that despite your motor having weak compression and suspect valves on certain cylinders, your car seems to run well, now that you got it going.

That's a dealership for you. I found that just mentioning that you spoke with Nissan Coprorate puts the fear of god in their eyes lol.



You can't go wrong with Cattman. Fastcats, as well as Y-pipes, headers etc. His reputation is solid in the maxima community. His products are a bit pricey, but they are the best built.

Here's one guy selling his unused new gen 2 cattman headers;

http://forums.maxima.org/8931530-post32.html

Cattman has a website but you are better off talking to him;

http://forums.maxima.org/8737201-post1.html

It's good to hear you got the car running again.

 

A wet compression test tells you nothing. You do dry first to get an accurate reading. Then a wet test will confirm the rings are the cause, rather than valves.

 

Hey DW - Thank you for pulling together the information. Also, I changed my profile to read 4DSC. :-) Somehow I picked up the wrong model sequence along the way.

I'm on the way out to the garage to swap coils with the I30 and check out a few other items. I need to clean out my garage so I can back the Max in it to work on the valve job. We are getting a lot of rain this spring.