Ok this is the whole shin dig...

-Bought my 1991 300zx TT 2 days ago...-Previous owner trained his car to take Cheveron with Techron 93 Octane fuel ( he says u can also put Texaco and Ammoco ), but he fails to mention this before i had this problem.-The Problem: I put in Citgo 93 Octane fuel....hence the problem starts.- The car would shut it self off after igntion automatically, if u didnt give it gas and rev it at 2 for about 3-4 seconds.-So i deal with that then later after 14 hours my car all of a sudden would not rev fast AT ALL. I have to rev it slow or it starts to bog as if its not gettin gas. and sometimes when RPM drops seems like the engine is about to shut off. It shut off twice since the problem. When i added the Citgo fuel and had the igntion problem i called the previous owner and he told me Citgo gas has toooo much dirt in it for the car. He told me to get Gas treatment asap, so i did and i was fine for a while. When my car wouldnt rev fast, me and friends came to a conclusion that it has to be dirty fuel injectors. Cause it seems the fuel feeds fine when u feed it little gas pedal, but when u try to gas it the fuel injectors seems as if they cant push out that much amount of gas. So then I put the fuel injector cleaner after i put the Chevron Techrin high octane gas. The problem still is there, so i went to a AUtoZone near here and they told me that the ****ed up gas is most likely still in the system and I need to burn the gas out that i have in there and put this Complete Fuel system cleaner, and then put the Chevron with Techron 93 octane gas. right now I have my car running idle burning the gas out. PLZ HELP IM LIKE SPAZIN OUT, I CANT STAND TO SEE MY CAR LIKE THIS!

I'd try getting a new fuel filter. Should be less than $20 at your dealer (only buy an OEM fuel or oil filter for your Z). Also, you could siphon the bad gas out, but I wonder if it's not just a clogged filter. Besides, with gas prices soaring the way they are, a new filter is cheaper than a new tank of gas anyway

Thx for info.

I called a z32 Specialist shop and they said it is probably the Spark Plugs being dirty.

Talked to this other mech he said drain the gas and let the car run until the engine shuts off. Then Put the new gas in, and turn the key to on position leave it there for 3 secs, then turn if back to off position and repeat 5-6 times so the injectors can get the gas in them before ignition.

This is my plan....1. Drain the gas put new gas.( Give old gas to father car )2. if that fails, put new spark plugs...3. if that fails, prolly get the filter....4. if that fails, take it to the z32 specialist and tell them to FIX IT PLZ!

Only reason im not going straight to the z32 mech shop is because it far away and my car now seems to overhear ( water pump or hose leak...). MAINTENACE IS A BLEECH! But it's all worth it if u own one of these and cruise down the highway.

Im currently taking donations for FIX MY z32 Foundation!

I'm gonna go out on a limb here and say it has nothing to do with the gas. It seems like the problem you are describing is classified as "hesitation" in the shop manual. I need more information to diagnose it though.

Basically the 300ZX goes through a set of fuel injectors every two years or less so that is something you can test by performing a power balance test. If you watch your engine and it rocks back and forth like a big v-8 during deceleration after you rev it then you most likely have a fuel injector or 2, or 3 out. If you have a DMM they should be in the range of 12.5 -14 ohms, any higher you better just toss em.

The other thing is only use NGK PFR-7B11 or PFR-6B11 spark plugs depending on how much power you are making. Never put anything else in there, it *will* run like crap, I guarantee.

Finally, make sure your car has had the PTS ignition amplifier replaced, there was a recall on that, but basically it either works or doesn't so, thats probably not the culprit here.

I'd recommend changing all the filters, oil, etc after buying a used car anyways, so that is #1. Then I'd check my plugs, do a power balance test and you should have found the problem by now.

Let me know if you need to know how to do a power balance test.

Regards,Peakhp

I know how to do the ECU Diagnostics to check for trouble codes.I would much appreciate it if u can tell me how to do a power balace test. Thx for you help!

With the engine at idle disconnect the connector to cylinder #1's coil pack. This causes there to be no spark in that cylinder. If the Idle rpm drops slightly then this means that cylinder is working fine. If the idle rpm is not affected at all, then that cylinder either doesn't have fuel, spark, or compression. There are other tests to diagnose these other things, but basically you want to know which cylinders are giving you problems, if any.

So when you are done with cylinder #1, put the connector back on the coil pack and move to cylinder #2 and repeat the same test. And so on until you are done with all 6.

good luck,

Peakhp

Whoorah!!!!!!!!! Got my z32 FiXeD!!!!!

Ok well I got my radiator replaced and looks good. Since my radiator was messed up and not cooling the engine, so the spark plugs were gettin overheated. The tips had a white frost to them. I replaced them myself, but it still didnt fix the problem. My Turbo hose was worn and was leaking air, and my right side hoses were mix-placed. The left one needed to be on the right one and the right one needed to be on the left one. After that I got a mild check up done on the ECU and the engine. The guys over at http://www.z1motorsports.com helped me out allot, and when the come back from Florida they gonna check it for boost leaks and more. Plus Im going to get my ECU from them when I go there ! BTW I got my JWT Pop Charger Air Filter installed and it helps allot.

Overall work done:Got the radiator replaced at a local shop - $275Changed the Spark Plugs myself - $90Installed the JWT Pop myself - $98Got the ECU checked & the engine http://www.z1motorsports.com - $35Got the Turbo hose replaced at http://www.z1motorsports.com - $25 including labor

Some more updates I have done..

ECU Upgrade - AshSPEC @ http://www.z1motorsports.comTurbo Jets Installed - Currently running 15 Psi Boost30 psi Boost GuageGREDDY Turbo TimerTuned right - Was IDling at 25 BTC, they got it to go back to 15 BTC at Idle( The ECU program was doing something of its own, so Ash decided to install his program and it worked great).

Previously Done:JWT Pop Charger ( for those who want dual intakes but worried about the BOG it causes on low HP vehicles, U can order z1motorsport Duall intake pipe and it works well even on stock z32TT)New radiatorSpark plugs

Future Plans:HKS HiPeR Exaust ( Current Custom Exaust SUCKS! )Unorthodox Underdrive pullyStronger Clutch

Theortically I am supposed to be running around 380 - 400hp, haven't Dyoned it yet.

Z32 also had a problem with cam position sensor connectors corroding or being loose on their terminals. the sensor is located on the left bank of the engine attached to the front timing cover right behind the radiator you just replaced. they would loose contact when the engine was reved and windspeed from the fan was disrupting it. is it possible when they replaced the radiator they pressed against it making the connection stronger? keep that in mind if your problem returns out of the blue. a way to test it is to have the car idleing and push against the connector if the car stummbles or dies i would recommend cleaning the terminal and tightening the pins in the connector to make better contact.

little bit of dielectric never hurt also