Picked up car yesterday, problems today

[cam99]

I bought a 1990 300zx TT yesterday that has 140k miles on it. (auto). Brought it home and it ran good. Put a new battery in it today and as soon as I started it up the check engine light was on and it had a miss. I pulled the plugs to see if any were wet, but all were dry and tan. Replaced them anyway because not sure how old they were. Ohmed out the injectors. All were around 12.5. connections were pretty crusty so I cleaned all the pins and reinstalled plugs with some dielectric grease. I think every connector on the car is broken in some fasion or another, which from reading on here is common, but it ran fine before so seems odd it would show up now. Pulled codes on ecu. 51, 53, and 45 came up. Injector issue from what I gather, but not sure where to go from here. It just seems odd that everyrhing was fine till I changed the battery? Am I missing somehting? Thanks

[cam99]

answer my own post. I pulled coil wires with it running and I have two dead cylinders. Moved packs but the dead cylinders didn't move, so certainly looks like injectors. I pulled one "bad" one and one good one and will switch and see if the problem moves with it to see if it's injector or power to the injector. Checked ohms and one is 12.5 and one is 14.4.

[cam99]

so switched the injectors and the dead cylinders didn't move. Checked the voltage coming to the injector and it was around 13v. About this time I realized that the coil connectors on the dead cylinders weren't sitting a far down on the coils as the rest were. Sure enough there was some old broken chunks of plastic lodged down where the clips are supposed to snap over the coils. None of the coil or injector clips are functional anymore so I didn't notice right away that they were still slightly elevated when pushed on. cleaned them out and low and behold the miss is gone. It's still running a little rougher than before, but much better than it did the last couple days. What I don't understand is why it started in the first place. I only changed the battery, didn't touch anything under the hood. So anyway I've got a complete set of coil and injector clips coming from z1

[cam99]

*crickets*
sooooooo. figured out the last little part of the rough running. The guy at the autoparts store gave me the wrong sparkplugs. was reading through a bunch of rough idle threads and started wondering which plugs I had got. Wanted oem ones. They were ngk, but not the right ones.They were a good bit shorter than the originals. Luckily I hadn't thrown out the plugs I removed, so I cleaned them up and put them back in. Runs like a champ now. I will probably do the 400hp kit so they will get changed out to colder ones anyway. The only real mystery at this point is what caused it to start missing in the first place.

[ZL8NING]

Gremlins!!

[cam99]

Gremlins!!

could be. I bought it on Friday the 13th

[ThisIsSparTTa]

You went from buying a 300ZX to changing injectors the next day? Have you owned a 300ZX before? If not I'm impressed by your drive, and your ability to search things out and pick up on new things.

FYI, you should figure out if you have new or old style injectors. If they are old style, you should consider replacing before they fail and cause more headaches. http://z32.wikispaces.com/Fuel+Injector

[cam99]

You went from buying a 300ZX to changing injectors the next day? Have you owned a 300ZX before? If not I'm impressed by your drive, and your ability to search things out and pick up on new things.

FYI, you should figure out if you have new or old style injectors. If they are old style, you should consider replacing before they fail and cause more headaches. http://z32.wikispaces.com/Fuel+Injector

LOl. This is the first Nissan I have ever owned. I was sitting around last week saying to myself, "self, I don't have enough stress and agony in my life so I should probably remedy that" So I figured buying a 25year old turbo import would solve that problem Went on craigslist looking for a starion or conquest, (I had a 89 Starion esi-r many years ago and it sure was a pain in the a**) and also searched for 300zx's as they were new when I was a junior in high school and remembered what an impression they made on me. So long story short this one was for sale about 20 miles away from me and I bought it without knowing a whole lot about it. Well it worked pretty good for about 48hours then it went south. Thankfully there is alot of good information on this site and I like a challenge. I checked the link you posted. I do have the old style injectors.

[ThisIsSparTTa]

Awesome man, well whatever you can't find on search we'll try to fill in the rest.

So yea, some things to consider: Ethanol in the gas now destroys the old injectors and is a super common problem. Most people either go to the new 370CC or up to the 740CC if they want to leave room for future mods. Staying with the 370CC, you could just change the injectors and the connectors (with an adapter kit). Going bigger would require a socketed ECU and a base tune from a shop like SpecialtyZ. Once you start down that slippery slope, there's other fun tasks to do too, like deleting the extra coolant lines for the throttle bodies. If you're already down at the injectors, I would recommend at least replacing the intake valve cover gaskets, because its easy enough and a cheap part. You can also do the exhaust valve covers, but its liquid gasket and a HUGE PITA with the engine in.

You should also consider a 120k kit if you don't know the last time the timing belt was changed. Timing belt breaking = interference = dead engine. It's good maintenance to do.

Anyways, welcome to the club. I'll let you figure it all out, here's a couple of info links, and links to the 2 most popular stores that stock our parts, if you weren't already on top of it:
http://z32.wikispaces.com/Intake+Manifold+Removal
http://conceptzperformance.com/
http://www.z1motorsports.com/

[cam99]

Awesome man, well whatever you can't find on search we'll try to fill in the rest.

So yea, some things to consider: Ethanol in the gas now destroys the old injectors and is a super common problem. Most people either go to the new 370CC or up to the 740CC if they want to leave room for future mods. Staying with the 370CC, you could just change the injectors and the connectors (with an adapter kit). Going bigger would require a socketed ECU and a base tune from a shop like SpecialtyZ. Once you start down that slippery slope, there's other fun tasks to do too, like deleting the extra coolant lines for the throttle bodies. If you're already down at the injectors, I would recommend at least replacing the intake valve cover gaskets, because its easy enough and a cheap part. You can also do the exhaust valve covers, but its liquid gasket and a HUGE PITA with the engine in.

You should also consider a 120k kit if you don't know the last time the timing belt was changed. Timing belt breaking = interference = dead engine. It's good maintenance to do.

Anyways, welcome to the club. I'll let you figure it all out, here's a couple of info links, and links to the 2 most popular stores that stock our parts, if you weren't already on top of it:
http://z32.wikispaces.com/Intake+Manifold+Removal
http://conceptzperformance.com/
http://www.z1motorsports.com/

Thanks for the welcome. I'll have to check out concept z. I've been all over z1, and even have a box from them sitting on my table, lol. All new connectors for coils and injectors. There was some service records with the car. The timing belt was changed at a Nissan dealer 3000 miles ago (however that was 2 years ago!) $1600+ ouch!! This car already reminds me of the 03-04 cobra's I've had with the "since I'm already doing xxxx I might as well do this xxxx". LOL. I smell a money pit

[ThisIsSparTTa]

You should be good on the timing belt then. Technically its 60k miles or 48 months. And yea, that fee doesn't really surprise me. The kit isn't cheap, and it does take a few hours. Probably a bit higher coming from the dealer, but still.

And yea, its a slippery slope indeed. However, most of the recommendations you're going to be getting are from us guys that did just deal with problem 1 up front, and then ended up having to deal with problems 2 and 3 anyways. I'm very guilty of this. However, I do know exactly what I'd do to a new unknown car now to go straight to reliable and running solid!

[cam99]

You should be good on the timing belt then. Technically its 60k miles or 48 months. And yea, that fee doesn't really surprise me. The kit isn't cheap, and it does take a few hours. Probably a bit higher coming from the dealer, but still.

And yea, its a slippery slope indeed. However, most of the recommendations you're going to be getting are from us guys that did just deal with problem 1 up front, and then ended up having to deal with problems 2 and 3 anyways. I'm very guilty of this. However, I do know exactly what I'd do to a new unknown car now to go straight to reliable and running solid!

That's exactly what I'm going to do with this car. try to sort out all the usual issues and have some fun with it. I'm going to do the fuel pressure test on it, change the fuel filter, just got two new bosch o2 sensors delivered today, and am going to do some sort of boost gauge. The stock one only reads around 7 psi at wot. Not sure if not making full boost, or the gauge is just off that much. I'm betting the cat's look like poop with the miles that are on it. Thinking of removing them also as I live in a no emissions county.

[ThisIsSparTTa]

I've seen a couple set of test pipes come up on the Facebook group recently for getting rid of your cats: https://www.facebook.com/groups/227766473927972/

Sounds like you're in safety boost, you should pull your engine codes if you haven't already. Most common culprit is the knock sensor. And, since you're on the good path, you can pull the codes at the ECU now, but I would highly recommend grabbing a $30 Consult to USB adapter from eBay and using free software like ECUTalk that not only lets you get codes without pulling ECU, but lets you read all the sensor values, which can be really helpful in troubleshooting. There's also $100 ConZult software which does some WILD stuff too, but not necessary for me.

http://z32.wikispaces.com/ECU+Diagnostics
http://z32.wikispaces.com/Safety+Mode

[cam99]

I've seen a couple set of test pipes come up on the Facebook group recently for getting rid of your cats: https://www.facebook.com/groups/227766473927972/

Sounds like you're in safety boost, you should pull your engine codes if you haven't already. Most common culprit is the knock sensor. And, since you're on the good path, you can pull the codes at the ECU now, but I would highly recommend grabbing a $30 Consult to USB adapter from eBay and using free software like ECUTalk that not only lets you get codes without pulling ECU, but lets you read all the sensor values, which can be really helpful in troubleshooting. There's also $100 ConZult software which does some WILD stuff too, but not necessary for me.

http://z32.wikispaces.com/ECU+Diagnostics
http://z32.wikispaces.com/Safety+Mode

If its in safety mode how do I get it back out?

[ThisIsSparTTa]

If its for the knock code (34), you will need to do a knock sensor relocation. Technically you can put a resistance on their, but its not recommended. The knock sensor isn't accessible without taking half the engine apart. So, instead there's a few good points on the plenum to mount it to, and at least you're getting some protection from it, and you'll clear the code. If you're ever tearing your engine down, then you can get at it and put a new one in the correct place.

Also, Z1 and CZP sell a modified knock sensor sub-harness thats more resistant to the problems of the OEM, which will help prevent more headaches in the future.

[cam99]

If its for the knock code (34), you will need to do a knock sensor relocation. Technically you can put a resistance on their, but its not recommended. The knock sensor isn't accessible without taking half the engine apart. So, instead there's a few good points on the plenum to mount it to, and at least you're getting some protection from it, and you'll clear the code. If you're ever tearing your engine down, then you can get at it and put a new one in the correct place.

Also, Z1 and CZP sell a modified knock sensor sub-harness thats more resistant to the problems of the OEM, which will help prevent more headaches in the future.

I didnt have that code when I last checked but I can check again. I have a boost gauge on the way so I can verify boost. So if I understand there is no procedure for removing car from safety mode? In the camaros if you get kicked into low octane mode you have to pull a couple fuses to reset the fuel maps.

[ThisIsSparTTa]

As far as I'm aware the only procedure would be to correct the issue, and then it will remove the code and safety mapping itself.

One other thought if you're not getting codes from your ECU and still running low boost is that the stock TT setup uses boost jets in the vacuum lines going to the wastegates. It's possible that someone replaced some vacuum lines and missed the boost jets. I pretty much did when I was reworking my engine. I have my stock boost jets somewhere if you need them. This is all better explained here: http://www.thumper300zx.com/z32/factory ... y_jets.htm

[cam99]

As far as I'm aware the only procedure would be to correct the issue, and then it will remove the code and safety mapping itself.

One other thought if you're not getting codes from your ECU and still running low boost is that the stock TT setup uses boost jets in the vacuum lines going to the wastegates. It's possible that someone replaced some vacuum lines and missed the boost jets. I pretty much did when I was reworking my engine. I have my stock boost jets somewhere if you need them. This is all better explained here: http://www.thumper300zx.com/z32/factory ... y_jets.htm

You sir, are a wealth of information! Thanks!! Okay I installed the aftermarket boost gauge tonight and I can confirm that the car is only making 5-6 psi. I haven't had time to recheck the ecu for codes, but I will when I get a chance. Read that boost jet link you gave. I will have to poke around under the hood and try and locate those solenoids. Seems like there was a good amount of overengineering on these cars. I'd like to do as many "deletes" as possible to clear some of this clutter up. Also my Hicas light is on and it feels and sounds like the power steering pump is on the way out....quickly. One step forward and two steps back

[ThisIsSparTTa]

Thanks. The safety boost solenoids do definitely serve a purpose if you legitimately have knock.

First thing I'd check for your HICAS light is fluid levels and the fluid sensor and its wiring. Commonly missed problem with these is that they take ATF , NOT power steering fluid which is thinner and will leak like crazy. If the liquid isn't red-ish and smells awful then its probably PS fluid. I would suck as much out as you can, fill it up, turn wheel back and forth a few times with car running, top off some more. In a couple days, come back, suck out a bunch more again, replace with new fluid, turn wheel, etc. That should hopefully get most of the PS fluid out of the system.