Major help needed please!!!!!!! about to burn a 300zx!!!

[PyroAnhell]

Hey guys. I hope there is someone that can help me with my Z because she is about to be burned to the ground. The issues I'm having now are a rough idle on start up (moving from 500-1500 rpm till it settles at around 1000) pulled out of my driveway after letting it settle and got up to 3rd gear at about 4000rpm going up an hill shifted to 4th gear and she bogged down and had no throttle response and was at about 1000rpm shifted back to 3rd got back to my house and when she was fluctuating between 500-1500rpm she would sound like she would lose power to the speaker because I had the radio on. Any help will be greatly appreciated and any questions will be answered quickly. Thanks guys


She is a 91 TT body with everything out of the one I wrecked which was a 93 TT swap with a lot of upgrades. I've had nothing but issues with this car since I got it back from my mechanic which I don't know if it's my bad luck or if my mechanic is just using me.

[PyroAnhell]

Got the weird idling to stop but the bogging down in 4th and 5th are still happening also the speakers have fixed themselves when I fixed the idling. Go figure haha

[PyroAnhell]

Scratch that last post because it fixed itself for one drive and is now not fixed.

[nissanfreak12]

Ok a list of questions;

1. Are there any codes in the ECU? Not just the check engine light, actually checking the ECU.

2. How are the connectors? Are they corroded with green crud?

3. Have you checked the injectors? Do they ohm between 10-14?

4. Has a boost leak been done?

5. Fuel pressure?

6. TPS adjusted correctly .45-.50?

I think this is a good start, something to go off of.

[PyroAnhell]

Thank you for the reply and I'm going to work on some of that tomorrow because I'm too pissed off at it right now to do it haha

[nissanfreak12]

Also check for a power balance test, if the idle doesn't change when you unplug a coil pack, that means that cylinder is dead. Unless someone has change to the new style injectors, I am assuming you have the old style. Those are prone for failure.

If all those fail, it could be possible you have failed cats and its clogged the exhaust. That will cause all sorts of issues, unless you have aftermarket downpipes and test pipes.

[PyroAnhell]

When my mechanic put the jdm from the wreck into the new body I found he upgraded all the injectors to nismo 740cc and did the ecu. I do have 3" stainless down pipes to stainless test pipes leading to hks hi powers.

[nissanfreak12]

HOw bad was the wreck? Was it a front end collision? Are you using that MAF from the wreck? That is very sensitive and prone to breakage on any impact.

Was the ECU tuned through a reputable company or did he do the "tuning" of the ECU. The car will run like poo if not tuned for the 740's. I would fined out from him if you can where he sent it to get tuned.

[PyroAnhell]

Here's where I'm at now.

Ecu showing code 55 (free and clear I believe)

Do not know status of injector connections I checked the injectors by unplug the battery and going to the harness from the ecu.

Injector test showed #1-12.1-12.4 ohms, #2-13.8-14.1 ohms, #3-11.9,#4-11.7,#5-11.8,#6-11.5

Fuel pressure- when car is off 43 psi, when in neutral at the rough idle changes from 38-45 psi, when at 2000 rpm stayed around 47 psi.

Did not know how to check tps on this car any diagrams will be helpful. Boost leak tester should be in Monday and will do a boost leak.

This morning cranked her up. Rough idle small amount of gray-white smoke coming out of exhaust. Weird grinding noise coming from alternator or near it. Did not smoke when I did the o2 test at 2000rpm. The o2 test came back good but was rich in the rough idle stage. After I did the o2 test I cut off but I was able to crank it right back up but cut off in 30 secs or less.

Any help would be appreciated guys and thanks in advance

[PyroAnhell]

Completely totaled, Said he replaced the maf, and supposedly z1 motorsports but with me looking at the ecu today I didn't see any indication that it was ever sent to z1 (thought they normally put a new tab on it giving The description such as TT 5 speed etc)

[PyroAnhell]

After I get done with work today I'll post the pics from the wreck and the video I took of it running today with the weird idle

[nissanfreak12]

Yes, Z1 will put what they did to it on the outside. Does that mean it wasn't tuned, not necessarily. Im sure if he did the ECU from
Z1 he more than likely got a MAF from them. But just to be sure, make sure it has an orange label with N62 on it. Should also say JECS, I think. If it doesn't have the N62, that could be a lot of your issues. Z's do not like any other MAF's. It also will not show up as being a bad MAF in the ECU, it just will tell the ECU the wrong signal causing a bunch of issues.

[PyroAnhell]

swapped over the mafs (I have dual intakes) no change. they both are jecs with n62 on them.

https://www.facebook.com/photo.php?v=10203973923448268

theres the video of it running. let me know if the video works and hopefully this will help you out.

[nissanfreak12]

Are you running SELIN or dual with a ECU tune?

[PyroAnhell]

Supposedly dual with ecu tune

[nissanfreak12]

I just thought of it, when I did my TT swap, I bought everything including an ECU that was tuned for a 91. I have a 92 body. I was able to use a JDM ECU and it ran perfectly fine, but the tuned ECU would barely run. I had it retuned for my car, have not had an issue since. Maybe call Z1 to see if this could be an issue.

It could be Coz was blowing smoke up my a**, but I have used him when I lived in AZ, never an issue. Whatever he did worked well.