Let me introduce myself, my names Taylor, I’m new to z’s and I’m in love with them(not mine at the moment). I bought a 83 280zx turbo last year and had a little bit of fun with it before I messed something up. I used to be a mechanic/painter for 2 years. I’m 20 with not a lot of knowledge yet. My 280 had a slight idle drop issue that bothered me so I read through a few forums and ended up cleaning some connections hoping that would fix it. I cleaned the tps, afm/maf(can’t remember at the moment) and the ecu connections. When I went to start it the car
wouldn’t start. I can get it to start with peddling the gas, but it’s extremely rough and sounds like it’s flooding. It will kill itself every time with no idle. White smoke is coming out the exhaust so my heart dropped thinking it was the head gasket. Dumped coolant and oil and both are fine. Coolant hasn’t dropped at all since, but the oil smells like gas. Which I hope the pistons rings are not the case. I love this motor and I don’t want to swap it.

Things I’ve Replaced before issue
Coil
spark plugs (now foul every time I start it) (wet)
injectors (pulled them about 4-7 times now, all click)
fuel pump
put a ground wire from battery (to fix a wiper issue)
Fuel filter
Fuel pressure regulator

things after issue
tps connector
chts
chts connector
carefully moved Carbon trail in afm/maf (was opened by previous owners)
Fuel pump (it does prime)
cleaned gas tank
put filter after the pump
Put old fuel pressure regulator back in
I may have done more I will update as I remember

parts I have sitting around (because their a pain)
exhaust studs and nuts (bad exhaust leak)
new gaskets for exhaust and intake
new/used tps
Maf sensor
cut exhaust before the cat invade of it being collapsed. Was told to by my old boss

I’ve done a visual check on vacuum lines and they seems to be fine. Can’t hear any leaks also.
fuel pressure seems to be there don’t have a pressure gauge and am fairly broke from putting money into this issue. Made the mistake of ordering rims right before this happened. Plus work is slow with the virus crap.

Ive read through countless forums probably 40+hours of reading no joke and have come up with swapping my old injectors back in to see if that fix it. Possibly a plugged fuel return line.
cold start injector
maybe running more grounds.
i feel absolutely helpless right now and am getting close to giving up. I’ve posted on another forum but got ridiculed for not helping other members before I ask for help... and got shot to other forums that didn’t relate to my issue what so ever. I’m happy to learn, test and help when I can, but I’m limited on my skills.
normal vehicles I do just fine in but this Datsun is a whole different ball game than what I’ve ever seen.
no shops in my location work on this year of Datsun's (only older models). Seems to be for good reason.

I’ve started reading the efi bible as I finally found a version I don’t have to download (no computer).
learned a few new things so far but I’m starting to come to the conclusion that it might not help me with this issue. I’m super confused and am stuck.
im okay with putting a few more hundred dollars into this old girl if needed but I’d rather not.

also a lot gas shoots out of exhaust leak when it does start (but only happens sometimes)
I’m eager to figure this out and help others I’m not here to get a fix and ditch I want this to turn into a passion. I get a fix from helping others so I’m happy to help. I know you guys are very smart and I could use some guidance. Thank you

 

If you have an exhaust leak at the manifold, keep in mind that the exhaust and intake manifolds share a common gasket. A bad intake gasket will make a car run like absolute garbage because it is a huge vacuum leak. I'd change that gasket, you said you already have one laying around. Yeah it's a pain, but it sounds necessary at this point. Worst case scenario, if it's not what's causing your current problem, it will still be good to have it out of the way for when you do get the car running right.

Also, '83s are electronic nightmares. I've had two different '81s and never had many issues with either, believe it or not one of the most reliable vehicles I've ever owned (I still have one of them, it's been more or less sitting since 2013, but still fires right up instantly when I turn the key). The '83 I picked up over the winter, well I still haven't driven it yet. Good luck

 

switchtr3 will do I plan to pull the motor soon to give me more room to work. I did see this when you sent it sorry it took me so long been busy. Thank you and yes the wiring is a nightmare to figure out. It’s like I’m trying to read Chinese. I plan to try to readjust the carbon trail closer to its original position in case I ended up making it to rich that way. I also plan on doing the tps at the same time I do that. I’ve had a hunch that maybe the intake manifold gasket is burnt up because the exhaust leak is pointing up at it. Maybe it was just on its last legs. Idk worth a go I think. I’ve heard it’s really difficult to get at it while the motors still in. But I might have to depending on if I can get a flip car I’m working on rn done. Thank you I truly appreciate it.

 

Hey Taylor, I ran into some very similar in my 82 recently, a couple things to check:
- Firing order
- Ensure you have set the distributor correctly (set cylinder 1 to top dead center and make sure the rotor is point to spark plug wire 1)
My issue was the rotor was one tooth off. If you didn't mess with the distributor before doing your cleaning. I wouldn't mess with this part but do ensure you have correct firing order.

Definitely install a fuel pressure gauge, this will help you diagnosis the issue. Its about 25-30$ which is not so bad.

 

dinhnerz I got some time to work on it today I defiantly will I’ll be at my shop in a couple hours. I gotta start paying attention to my thread more sorry about that. I might have, but I don’t believe I did. The next time I’m getting parts I’ll get a pressure gauge. Where Is the best place to install it?

 

Ok, so I figured out the issue but I have a new one.
the issue was I had a frayed wire on the afm connector I had to reuse the old metal piece (cant think of the name) that Goes into the afm connector cause I can’t find them anywhere except ordering them online. That fixed it not being able to run! So now the issue is that when at low idle up to 3k it backfires like crazy and has no power up until then. I took it around the block to see if I could clear some crap out and once it hit 3k it pulled hard and ran like it should. It took a while to shift so I gotta check the tranny fluid.
the plan for tomorrow is to drain the old gas and oil.
the gas is about 6-9 months old so it’s bad.. The oil has gas in it which I feel might be part of the issue. It needs to be changed anyways but could be part of the problem. If you got any suggestions let me know!
I haven’t smiled like this in a while. Wasted a lot of money just to see a small fray in wire out of the corner of my eye lol.

 

I put my fuel gauge right after the fuel filter and right before it goes into the fuel rails. Glad to see you got the car up and running, its definitely one of the most memorable moments for me as well.

 

dinhnerz thank you. The next time I can get to the ole girl I’ll slap one in there. It felt great that’s for sure a little heartbreaking having a new issue right after though.

 

Do check fuel pressure and whether your fuel pressure regulator is ok. Maybe you can borrow a pressure gauge at an auto parts store. I had a (fairly new) pressure regulator rupture the diaphragm and it dumped raw fuel right into the intake through the vacuum line. That much fuel can wash down the cylinders and end up in the oil. Check there's no fuel in the vacuum line. 9 month old gas should be fine. Also check ignition timing. And I would double check the connections you cleaned, right before your problems started. Good luck, and keep us posted

 

cees-klumper will do, thank you. I have a new fpr but I swapped it to try to fix the other issue. I’ll swap the new one back tomorrow. How do I check the vacuum lines for fuel and which ones? I’m taking it just pop them off and see if it drips?

 

Yes, remove the vacuum line attached to the FPR and check if it contains fuel.

 

cees-klumper I checked the vacuum line and no fuel seems to be in there even tried to suck on it and nothing. It does smell like fuel but I’m guessing it probably will. I swapped the fpr with the other one I should’ve ran the original one to get a baseline for the day again. But now at idle it doesn’t backfire. Still sits inbetween 5-600 rpm. I’m gonna fix a couple crappy wire jobs I did. I did them just as a quick fix and didn’t think of long run. And it sat through winter so I’m sure there corroded. I’m up here now and I’ll up date you guys as I go. Thanks

 

So I fixed the crappy wire jobs I did, now there good.
i popped the distributor cap off and the connections are corroded pretty badly. So I cleaned them up(I will replace the cap when I get more money). Didn’t change a thing after I cleaned them. I’ve got new ignition wires I’m gonna throw in. I’m gonna pop a couple of the spark plugs to see how they look. I wish I could figure out how to upload a video for you guys. I tried but it won’t work for me I could email it to you guys maybe if wanted. Let me know. When I can get to a part store I’ll get a fuel pressure gauge and let you guys know what it reads.

 

Here’s a video hopefully
didn’t seem to work

 

if you need a different video or different view of things let me know I’m happy to get that for you guys

 

Try throwing a fuel gauge on there and see if there is a fuel pressure drop during that RPM range.
I would check if the exhaust is clogged, try running it with open downpipe.

Do you have any kind of backfire? either intake or exhaust.

 

dinhnerz I’ll throw one on there when I get paid on Friday. I’ve got another video of it I can upload of it running a little worse. It backfires through the intake and exhaust randomly. Before I swapped the newer fpr back in is when it was running worse it was nonstop backfiring back and forth inbetween the exhaust and intake

 

How about when the engine is warm? My engine takes about 12 minutes for it to warmup (thermostat removed) and go into closed loop. It runs a lot better once warmed. I get slight back when the engine is cold.

Having a fuel gauge should definitely help you determine what the issue may be. Also try adjusting your ignition timing (advance/retard by adjusting your distributor).

 

dinhnerz I ran the car for about 20 plus minutes before I made that video and it was pretty dang hot.
Im gonna get a new cap for the distributor on Friday also since mine is corroded pretty badly. Curious about how to go about rotating it. My ignition wires are pretty tight and don’t allow for much play.

 

You can take some sand paper to the rotor and cap to clear that up or a wirebrush.

You loosen the 2 bolts that bolts down the distributor to the engine. Once loosen, you should be able to turn it clockwise or counter counterwise which will then adjust your ignition timing. Also you may be a tooth off on your distributor or have your firing order off.

Did you ever remove your oil pump?

 

I did take some sand paper to the points inside the cap. It made no difference. I never messed with it before so idk how I could be off unless it moved itself. Not saying that it could’ve happen some how.
I’m not really sure on how to check the timing on that. With my firing order I had a hunch that that first two plugs I might’ve swapped on accident so I swapped them and it barely ran so I’m pretty sure I’m good there. Other than that I’m pretty careful when it comes to plugs and plug wires. I haven’t messed with the oil pump at all. Could that be a cause to my issue?

 

For a insanity check, you can rotate the crank pully to have it line up to the 0 marking on the timing cover. This will put the cylinder #1 in top dead center.
Remove the distributor cap, the rotor should point to #1 spark plug, if it doesn't then its off.

 

Haha, yeah I can do that give me about 20-30 min to get up to my shop. I’ll let you know

 

Idk if I’m an idiot or not but I’ve rotated the crankshaft pulley twice now and I’m not seeing any markings. Also not seeing a 0 on the timing cover is there a certain angle I should be looking at?

 

heres another video for you guys for some reason I can get the Rpms higher today