1993 Nissan 300zx Na to Tt swap complications

[Jamisongg]

If anyone could help it would be awesome. I bought a 1993 Nissan 300zx NA 2+2. I did a full tt swap. I am having trouble with it. The car will start every time, it will idle for hours, but it will not rev over 4000 rpms. I have bought new sensors, but still have not gotten a change. I have 2 or 3 mass air flow sensors, 2 or 3 tps sensors, I have replaced several parts. But still cannot get it to run over 4000 rpms. I checked for codes on the ecu self diagnostic and it reads code 42, I have replaced the fuel temperature sensor and also the the wire connector itself, it reads 14 volts, but I still have the code. I will post links to 2 videos showing the car having this problem.

[Rogue One]

Fixed video links and deleted duplicate post.

[Jamisongg]

Thank you.

[Ace2cool]

If it's not revving past 4k, it's in safety mode. If it's still showing a code, it's still a problem. Check the EF/EC section of the FSM for the troubleshooting procedure.

http://www.nicoclub.com/FSM/300zx/1994/ec.pdf

page 135.

[Jamisongg]

I have replaced both the sensor and the harness. What else do you suggest I do in terms of getting it out of safety mode then?

[Ace2cool]

You still didn't answer the question that the FSM specifically asks of if there is continuity. I understand there is voltage, but that doesn't mean that the wire doesn't have high resistance. Wires can get pinched and broken. You could also have a short. Or even an issue with the ECU.

[Jamisongg]

Okay I understand. I highly doubt the ecu is faulty. I just purchased it off of z1 a month ago and is specifically set up for the car. And as for the fsm, I am confused what you mean by that.

[Ace2cool]

I'm not sure how much clearer to get. One lead of the meter on the correct ECU pin and the other on the connector itself.

And Z1 has sent out bad ECU's before. It's just the nature of dealing with electronics.

[Jamisongg]

Okay. I will check the continuity between the two and see if there is a problem.

[itsa300zx]

Have you done a boost leak test yet?

[Jamisongg]

checked for voltage, voltage is good. Checked for continuity, it is good. Also did a boost leak test. No boost leak.

[evildky]

Check the knock sensor and knock harness.

[Jamisongg]

I have a knock sensor bypass on for the mokment to make sure it is running correctly.

[Jamisongg]

I did a second test on the fuel temp sensor. It is reading .14 volts out of the pin of the ecu. Not 14v. Which is too low. The continuity is good. But it is reading .14v out of the pin.

[Ace2cool]

Sounds like you've got it figured out then.

[Jamisongg]

I I ran a wire from the pin to the sensor and it made no difference and then I also made sure the ground was good and grounded it to the chassis. Still no difference. Still .14 and I'm not sure what else to try.

[Ace2cool]

There's a chance that the ECU you got is bad. Do you still have your old one?

[Jamisongg]

The one I have is an upgraded ecu, it is designed for a na to tt conversion, TT injectors, and a 2+2, I only have a NA ecu and TT ecu without tuning

[NolimitZ32]

What injectors are you running, there is no 2+2 tune, they may have tweaked the tuning a bit but if you are running stock TT injectors than a stock TT ecu will work fine, Auto ECUs work on manual cars as well.

[Jamisongg]

On z1 you can buy an upgraded ecu, in the specs, I chose 1993 2+2, na to tt conversion, manual, dual intake, and 555cc injectors. Thoes are the exact specs of my car. I have 555 injectors in the car. It has you choose from a list of stuff to design in for your car.

https://www.z1motorsports.com/z1-produc ... s-p-5.html

[Jamisongg]

Unless, the upgrade doesn't work on 93 2+2's.

[NolimitZ32]

1. 2+2 makes NO difference, period end of story. They ask that on the website for their own marketing purposes and records or if you buy other parts such as a drive shaft that is different for the 2+0 or 2+2. ECUs don't care (this tidbit is for your information only not for arguing).
2. How are your dual intakes set up? Are you running an SAFC/ Selin Translator Split MAF setup or a live MAF/dummy MAF setup?
3. Since you have 555s then a stock tune wont work so testing with a good known stock ECU wont work.
4. From the video it looks like you're running RICH as all hell which could mean a number of thing from a pinched injector o-ring to the wrong k-factor. How do your plugs look? how's your fuel pressure? have you confirmed compression? how old are your O2s?

[Jamisongg]

Okay. Thank you. What do you mean as in how the fuel intakes are set up? I have 2 side mount intercoolers. I have the an oem tt maf sensor on there. I didn't change anything about that. Yes its running beyond rich. I can smell fuel from exhaust. The injectors are new. I didn't put new rings in though. Plugs are all black. I've replaced them twice. I have the plugs from z1 recommended for the tt. And fuel pressure is about 42lbs at idle and goes to about 48lbs at rev and stays steady. Compression was checked no problems. O2's are the original na o2. Not replaced. Checked them with volt meter and also checked for continuity and seemed in specs.

[Jamisongg]

Dual* was autocorreced to fuel* in my response.

[evildky]

Have you verified spark at all 6 cylinders? A rich condition can be due to lack of spark due to a bad cas, ptu, harness, ecu, cop or plug. If spark si good on all 6, the O2's, CTS and FTS can all cause a rich condition to the point of fuel fouling the plugs.

[Jamisongg]

What's the easiest way to check for spark and make sure that isn't the problem I'm having.

[NolimitZ32]

So you're ECU is tuned for dual intakes but your only running 1 actual intake. The "Dual Intake" doesn't refer to the number of intercoolers, it refers to the number of intakes that you have. When you remove the nose panel the factory airbox lives under there or whatever has replaced it. I'd be willing to bet that you have the factory airbox with a single MAF or a single Popcharger with a single MAF, if your ECU is in-fact tuned for Dual Intakes and you are running a single maf that splits to the two sides then this is your issue. You need to read up on the Dual Intakes setup. Search for Z32 dual intakes or dual pop or dummy MAF.

Your free fish: https://z32.wikispaces.com/Dual+Intake

If this is the issue, luckily for you all you'll need is a dummy MAF, the elbow kit, and a second Charger/filter. That's assuming that Z1 tuned for that setup, you might want to contact Z1 and find out which map is on your ECU. This would be the "k-factor" thing I mentioned earlier.

[Jamisongg]

Oh wow.. I do have a single.. I will call z1ans find out the map right away to see which I need. Thank you so much. I will get back to you as soon as I see if that works.

[NolimitZ32]

Glad I could help. Since you already have the ECU (I'm 99% that you got the tune for a dummy MAF setup) I'd spring for the components to go Twin Pop, but that's just me. Good Luck.

[Jamisongg]

Would it do any harm for me to send it back and just get the same tune but for the single intake. Itd my cheapest route.