Let's see if you guys can help me again. 2002 maxima. I just put an 04 motor in (had to keep some 02 things) and drove the car for 3 or 4 days. I had 0 issues. The car drove flawlessly. P0507 popped up and I cleared it and it came back. I cleared it again. Further research tells me I have to do a relearning process.
I was driving the car when it went into limp mode. It wouldn't go past 2400 rpms. However once I got to 4th gear it started dying all the way. It died a few times but I thought I could make it to an auto parts store... I did not. It finally died for good and I had to push it.
The car will turn on and then immediately die like it has a catastrophic vacuum leak or something, or it will only crank, or it will never fully turn on but gets close. I got a code reader and checked the codes. I had p0507 and a maf code and maybe something else but I don't remember. No matter how many times I failed to start it I couldn't get a code to come back on. I tried unplugging the maf and I tried replacing the maf. They symptoms do not change. I assumed it was a maf because I drove the car probably 100 miles with out the intake box on. Please give me advice. My car is stuck at a park in ride and I am willing to try anything. I have the throttle body off of the 04 motor that I can go pick up and try after 1pm.

 

IACV valve leaking coolant and shorting out ECU sounds like the problem.

 

I thought 02/03 don't gave the iacv?

 

the 5.5 gens don't have an IACV. foodmany must have mis-read the year of your car.

But you need to take care of the P0507 code. That is your problem. P0507 is "Electric throttle control actuator Intake air leak."

Read pages 446 & 447 in this FSM link

 

I don't understand why the car ran great with the new motor for 4 days and then randomly goes into limp mode and then full on takes a dump. This is what it is doing: https://youtu.be/yzmzvu_F2xQ
I reset the ecu and I changed the maf and the tb. Still can't get any codes because I can't get it running.

 

Starter?

 

How can it be starter...its turning over?

 

oh is it then I think it's one of those sensors crank or cam

 

Also, I found this strange. When I swapped throttle bodies yesterday and turned the car on it tried to idle for a few seconds. But even with the accelerator fully depressed the rpms did not move. Before it seemed like giving it gas was at least doing something, but this time it felt like the throttle had never been touched.

 

By the way, I've never had a code for the cam or crankshaft position sensors.

 

Any ideas? I will try anything. The car only cranks now. I feel like it has to be something electronic. The throttle plate never moves when I give it gas with the ignition on. I've checked every ground and connector.

 

So i went back to my old motor to try swapping the sensors. Am i crazy or do i not have a crankshaft position sensor? I have looked everywhere and cant find one. From everything i read online it looks like it should be herw.

 

^
wrong spot

look at the front of the car
look at the right

 

Oh its between the transmission thanks. I guess I will have to buy a new one. I doubt camshaft sensors could keep it from starting

 

Maybe... I only have sample size of ME. I changed the one with a weird connector type I had to use flat head screw driver to get it disconnected and it fixed the from cranking and sometimes starting to cranking and always starting. It was nearest to front valve cover area on the right

 

Ok...maybe i'm a beginner---but have you checked the Fuel Pump and Fuel Filter?

They are in a weird Spot--- located underneath the Rear Passenger Bench Seat. You have to remove the Rear Seats to get to them...but, its not that expensive a part (the filter).

I believe i saw a video of it on you tube.

Here it is...



.

 

I would have checked but I can smell fuel when I try to start it. I suppose I can check anyway.

 

Swapped the crank sensor and the front cam sensor as I found those from the old motor. Lifted the back seat to hear the fuel pump turning on. Still won't start. Just cranks. What other issues can prevent the car from starting and cause it to go in limp mode while driving originally and start a few times before ultimately checking out?

 

I would check into what Dennis Said...he knows his stuff on these cars.



.

 

I don't doubt it. However that route was a quick dead end for me: I don't have consult 2 and I can't get my engine to idle. Therefore I can't really follow anything on those two pages.

 

The only thing the manual is doing with the CONSULT is seeing if you have the P0507 code - "If 1st trip DTC is detected, go to “Diagnostic Procedure". But you do have to get the engine to run to check for an air leak. But as the manual says, if it is not an air leak, the ECU is fubar.

In your car, the gas pedal does not connect to the throttle assembly. When you step on the gas pedal, it moves a sensor that sends a signal to the ECU. The ECU then sends an electric signal to to the throttle control motor in order to have the throttle open up.

If you have a bad throttle control motor, you theoretically should have a P1128 code. If you want to read about it, start on page 485 in that link I posted. But on page 489, the FSM tells you how to do a resistance check on the motor to see if it is good. Why don't you do that for piece of mind.

 

Isn't the throttle control motor in the throttle body? I swapped out the throttle body and it didn't make a difference. Is there a way to check the ecu to see if it is bad? I would hate to order another part I don't need and use up my last aaa tow going to a dealership to recode keys and then the car still not start. I will do more reading but I'm just about tapped out. I feel like I have read every post on here.

 

And I can't get any codes to show up. I rented an obd2 reader. But if I disconnect any sensor if fires a code immediately on a failed start. But no matter how many times I crank it with everything plugged in I don't get an ses light or any codes.

 

The throttle control motor is attached to/part of the throttle body assembly. But if you had a shorted throttle control motor, it would most likely damage the ECU, probably causing the driver integrated circuit chip to burn up from current overload like the 2000 & 2001 Maximas do.

If you open up the the ECU and look inside, you should be able to see a burned up integrated circuit. But I really don't know if a shorted throttle control motor would even cause a chip to burn up. If there is no visual indication of damage, then you (and I) have no way of telling if an ECU is bad as it requires a computerized tester.

If you were to have a shorted throttle control motor and it damaged the ECU, swapping another throttle control motor isn't going to fully resolve your problem because the ECU would also need to be repaired. Get your ohmmeter and check the resistance of both of those throttle control motors.

And no matter how complicated the car may be, it still needs 3 things to start: Air, Fuel and Spark. Which one(s) are you missing?

 

Thanks you have been helpful. That is what I have been trying to figure out. I'm going to assume it is an issue with either the fuel or the ecu. I feel like the ecu isn't allowing the car to turn on. I'm not losing fuel anywhere. No leaks under the car and I wastill averaging 20+ mpg before it stalled out. It makes 0 sense that all 6 coil packs could go bad at the same time and I haven't seen any visible vacuum leaks.

 

I guess you don't realize how broad of a statement this is. The ecu controls both the spark and the fuel, so you are probably correct in that respect. But then, if the throttle control motor isn't working, you wouldn't have any air, either.

So we need to know if it is a spark or fuel problem so we can check the appropriate sensors, parts or whatever.

One thing you could try to prove or disprove the fuel part would be to get some starting ether and and spray some in the intake manifold and see if the engine will start.

Another thing is to take an ignition coil off. With the coil still plugged into the wire harness and either a spare spark plug or the spark plug from the cylinder, ground the base of the plug to the engine and crank the engine. if the ECU is firing the plugs, you will see the spark.

 

I just skimmed this post so sorry if you've tried this but did you pedal dance the throttle relearns/ecu resets?? It sounds very familiar to what I just had an issue with.

 

Please watch my video and see if it is similar. I did the ecu reset pedal dance and nothing changed. Also I just did the spark test and am getting spark. There is no big vaccine leak so I assume it is down to fuel.

 

I used starter fluid and the motor turned over and stayed on for about 10 sec. So it clearly is a fuel issue.

 

OK. Two areas to check.

1) Is the ECU firing the fuel injectors?
2) Is there a sufficient fuel supply to the injectors?

1) I consider this to be the easier one to check. You need to use a voltmeter for this.
The wire harness connector for a fuel injector has 2 wires in it. One of the wires is red and every injector has a red wire. This wire is 12 volts when the ignition switch is turned. Check this on any one of the injectors just to make sure it is OK. The other wire is the one from the ECU to fire the injector. Set the voltmeter to measure a.c. volts and monitor this wire while the engine is cranking. The reading on the meter is going to jump around, it will not be steady. If the meter reading doesn't move, then the ECU is not trying to fire the injectors.

2) To me, this is kind of a guess work thing. What you can do is swap the fuel pressure regulator (Nissan calls it a fuel damper) with the one from the old engine and see what happens.

 

Tell me about the fuel pump. I pulled it out and obviously there are no viable signs of issues. I didn't know what to do with it so I put it back. Now, when I turn the ignition on island can hear the fuel pump turn on but only sometimes. It is hit or miss. If I shut the ignition off and turn it on like 10 times, I will here the fuel pump maybe 4 times. And if I crank the ignition with out engaging the clutch, I can hear it pumping away. But the motor isn't getting fuel. Are there two parts to the pump? Is there a pump and a sender and the sender part could be bad?

 

I have an extra fuel rail laying around so I will try that next time. I'm going home and the car is 40in from my house at a friend's.

 

The fuel pump is just a pump submerged in the gas tank. There is a control circuit (the good old ECU) to have the pump run or not.

The way the fuel pump works is that when the ignition is turned on, the fuel pump runs for about one second to pressurize the fuel lines. After this initial one second, the ECU has to detect pulses from the crankshaft sensor or it will shut off the fuel pump. Cranking the engine will produce the pulses, so the pump will run and you are confirming this.

The part about you not hearing the pump every time you turn on the ignition - I don't have a definite answer for that. What I suspect could be the case is that you will hear the pump run when there is no to little pressure in the fuel system. But if the fuel system is still pressurized, there is a back pressure on the pump and it runs slower because of the load. Running slower is quieter. This is just my theory.

In my car, I can rarely hear the fuel pump at any time. The only real way to know if the fuel pump runs is to - are you ready for this? - get out your volt meter and monitor the power wire to the pump.

When it comes to a voltmeter, I don't think that you have one. Correct me if I'm wrong, but base on things you have said, or more specifically have not said, I have come to this conclusion. And you really have to have a voltmeter if you want to work on cars now-a-days because just about everything is controlled by a microprocessor and sensors.

For $25 you can get a decent quality voltmeter with the auto ranging function. The auto ranging function makes using the meter a lot easier, well worth the extra $5.

 

I checked with the back seat out. Pretty easy to hear. I have a voltmeter it just needs batteries. So my next step when I go back to the car will be checking the injectors. Let's say they are not getting a pulse, is that an ecu issue or a relay?

 

There is no relay for the fuel injectors so it fall back on the ECU. But is the ECU getting all the info it wants to have in order to fire the injectors. That is what we will have to work backwards from the injectors to figure out.

As an example, if the car were immobilized by the NATS, the ECU will nor fire the fuel injectors. Speaking of NATS, is the security led off when you are trying to start the car?

 

No. And there are no codes. Everyone else with nats or bad cam sensor that I have seen has a code.

 

Oops I meant yes it is off.

 

Yea I think you may need too pedal dance. It's not hard timing is critical. Start with ecu reset then all of the relearns. Once you get them to work and your car starts and idles right be sure to disconnect the negative battery post for 10 to 15 min. I see your in NJ if you continue to have problems I live in Burlington county. Get back to me if I can help I will.

 

Idk what says I live in NJ, I actually live in Washington state. I believe I did the pedal dance right. I always got the ses to blink. Also, I got the car to start with lighter fluid so I no longer believe it is ecu related (hoping). It stayed on for about 10 sec before dying. So I'm pretty confident I am having a fueling issue.

 

Maybe it was late last night but I could've swore the car in video had nj tags?? I may have well been up to late too.