Well I spent about an hour searching for the timing mark on the crank pulley and see nothing. Sprayed a ton of degreaser all over it and scrubbed it as best I could, but still see nothing. I do have the white out tho, borrowed some from a guy at work.

Got a little frustrated at not being able to find something so seemingly simple, so instead of pounding my head against the wall I pulled all the plugs out and cleaned them off. They weren't in very good shape, brand new but covered in black stuff.

I also looked for the spring on the AFM, no dice there. I'm guessing it's inside and I have to pull the AFM to get to it? No more for tonight, gonna watch the rest of the Louisville football game and come back to the car with a clear head tomorrow after work.

 

The timing mark on the pulley is a notch. If you run your finger around the perimeter of the pulley you should be able to feel it. It's on the inner pulley.

The spring is indeed inside the AFM. If you go to the main page of this forum you'll see a sticky on rebuilding/modding the AFM. It'll walk you through the AFM process.

 

Here's a pic of where the timing mark is on the crank pulley as well as where the front cover timing tab is.

Pic is courtesy of Nismopics Z

 

Thanks for the pic, hopefully that will help. Mine looks a little different, how there's no radiator and fan smashed up against those pulleys and belts?

I talked to a guy at work today and based on what he said, I think I wasn't looking at the right pulley. The one I was looking at and cleaning heavily was the one that the fan comes out of, he said I should be looking at the pulley all the way at the bottom of the engine. Based on your picture, that sounds about right.

He also suggested that my problems could possibly stem from the timing chain slipping a tooth or something like that. I wish I would have spent more of my youth under the hood of a car....anyways, I'm pretty sure my car is legitimately at 112K miles. Is that scenario possible, does that ever happen with the z's.

Thanks again! Time to go face off against the car again.

 

J... always on top of things!

Yeah... to make timing a lot easier, get some liquid white out & dab it on the V on the crank pulley.... VERY visible when timing. That pic was taken when I was installing a new metal headgasket & higher amp alternator. Hence the reason the radiator is out, and no lower coolant hose.

I'm 99.999999% sure it's not the timing chain that has slipped a notch. That is VERY hard to do on the L28 engine. If that did happen, I doubt the engine would still be running at all.

 

Cool, very reassuring to know that...so how in the heck are you able to see the timing marks while setting the timing. I have made progress, I know where they are now but holy cow that is cramped. I have to jam a light down the side and stand at the perfect position to see it. So far any time I stick my hand down in it I lose sight of it, so I'm not sure how accurate I'll be with the white out.

The car is just screaming for me to take it to a shop, but I'm not going to listen just yet. That AFM tutorial is great, I thought I had read all the stickies but I missed that one somehow. Lot of good info there and moving the circuit board is just brilliant.

 

Well it still isn't runnin right, but I think I'm onto somethin now. I was rechecking all the tests per the FSM and noticed that pin 108 didn't have continuity with body ground, which it should according to the manual. Then I looked at the handy schematic provided in the FSM and found pin 108 to be the air regulator. That was one I missed when I went thru and cleaned all the connectors, so I thought the car was going to pur tonight.

I took the air regulator completely out, cleaned the connectors on it and on the harness that connects to it, disconnected the two ground wires that bolt on right behind it and cleaned those real good. Things were going so well that it even stopped raining outside. Did the component test on the air regulator and it tested fine. It read 75 ohms across the two contacts. Sweet, one part I don't have to go out and purchase!

Before removing it, pin 108 to ground was reading 3.5 M ohms. With the regulator out I put a wire jumper between the two connectors on the regulator harness and rechecked pin 108 to ground. It is still in the 3.5 M ohms range.

So I'm pretty sure that there is some serious corrosion in the wires somewhere between the ecu harness and the air regulator harness, but I've cleaned each end til my hands went numb, and still no better.

Right now I'm thinking it might be easiest to just run new wires, but I'm certainly open to suggestions. I've traced the wire as far as I can see, but don't see any breaks or crack in the conduit. I'm sooooooo close I can feel it.

 

nismo, you still running your ps and a/c. cause you ain't got no belt....kinda like how mine's looked the other day...and nice alt and red bracketry ,and whats that sensor that runs in line to the heater? not shown in pix.

 

PS yes... A/C no. I removed all a/c shiz. It's not my daily driver, so I don't cruise it in the heat of the day too much.

That sensor is either a water temp sensor or control valve for the auto climate control unit. I didn't yank it when I swapped back to manual controls... will do that someday. Pic attached.

 

this one right hear. in pix. and which mls should i get 1mm or 2. what the diff? oh and i just redid my belt in the ps. its much better...even with the bent pulley. and dam you nismo thats one clean *** engine...i hope you like grease when you get to my car. my computer is bull shitting so no pix til tomorrow. yeah my computer sucks ballz

 

uh... I can't see where you are pointing

The difference is 1mm. 1mm will raise compression, 2mm will lower it.

I hate dirty engine bays! Decrease it before you come down.

 

hte 1mm will raise your compression ratio. The 2mm will most likely lower it. The stock gasket is something like 1.2mm when compressed. Or something like that

EDIT: Nismo beat me to it

 

Well it still isn't runnin right, but I think I'm onto somethin now. I was rechecking all the tests per the FSM and noticed that pin 108 didn't have continuity with body ground, which it should according to the manual. Then I looked at the handy schematic provided in the FSM and found pin 108 to be the air regulator. That was one I missed when I went thru and cleaned all the connectors, so I thought the car was going to pur tonight.

I took the air regulator completely out, cleaned the connectors on it and on the harness that connects to it, disconnected the two ground wires that bolt on right behind it and cleaned those real good. Things were going so well that it even stopped raining outside. Did the component test on the air regulator and it tested fine. It read 75 ohms across the two contacts. Sweet, one part I don't have to go out and purchase!

Before removing it, pin 108 to ground was reading 3.5 M ohms. With the regulator out I put a wire jumper between the two connectors on the regulator harness and rechecked pin 108 to ground. It is still in the 3.5 M ohms range.

So I'm pretty sure that there is some serious corrosion in the wires somewhere between the ecu harness and the air regulator harness, but I've cleaned each end til my hands went numb, and still no better.

Right now I'm thinking it might be easiest to just run new wires, but I'm certainly open to suggestions. I've traced the wire as far as I can see, but don't see any breaks or crack in the conduit. I'm sooooooo close I can feel it.

 

it says the file is too big to upload, so it the one that runs to the heater, off the water return to the radiator? i guess thats what its called. so i should get a 1mm mhs. ok

 

I figured out that the reading on pin 108 will always read funny when the key is in the off position. It only reads 75 ohms when the key is in the 'on' position.


The good news is that I finally found the notch on the crank pulley. I actually found it while it was on the opposite side from the timing bracket by running my fingers around it (thanks fairladyz) after scrubbing the bejesus out of it with engine degreaser and a wire brush. With my tps disconnected and the rpm's around 3000 it is at 20 degrees, but if I let it go down to idle it appears that the timing shifts to about 16 degrees. Is this normal? The car is warmed up while I am testing it...but what rpm should the car be at when setting the timing?

 

The ecu does advance the timing depending on rpm & throttle position, but yes, it should be 20 degrees at idle w/ the TPS disconnected.

 

Thanks!

Guess I have to move it back....I had it perfect at idle, but at higher rpm's it was moving to around 14-16 so I monkeyed with it some more. At least the white out is still there, that's the hardest part of the whole thing.

It was definitely idling much better than ever, but was stumbling when I'd give it gas. I guess it's time to buy an air/fuel gauge and move along in the troubleshooting process. It's nice to have a little progress tho.

 

If it runs better once you've adjusted the timing, leave it there. Just stay in the range of 14-22 degrees.

 

Well it was slightly better where I had it before. The very last adjustment I made had it running slightly rougher. I'll see how it starts and idles cold tomorrow, if it still seems a little worse I'll move it a hair and try to get it back where I had it.

I'm not sure if I was imagining things or not, but I could have sworn that for awhile tonight the smell of gas went away. It did hold a steady idle for a good five minutes with the CHTS plugged in, that's the first time I've been able to do that since I got the car.

 

Update



Plugs, wires, dist cap and rotor have all been replaced. Timing has been adjusted to 20 degrees with the tps disconnected. It starts fine and seems to idle fine with the CHTS attached. If I disconnect the CHTS, the car stalls. I'm hoping that's what it's supposed to do?

It also seems to rev fine, but if I put it into gear and try to drive it, it runs bad. Feels almost like it's missing a cylinder, tho I'm not too sure if that's it or something else going on that makes it feel like that. I've cleaned all plugs and contacts. Checked the air regulator out of the car. Did the AFM rebuild, moved the circuit board a bit...tonight I moved the adjuster around a good bit, when I moved it towards a richer setting it seemed to run worse, I've got it about four teeth to the lean side and that seems to make it sound a bit better when I rev the motor. I no longer smell gas when I'm running it, but still runs like crap under load.

Just kind of hoping to get pointed back in the right direction. From extensive searches here I seem to keep getting the exact same threads, but from the threads I was thinking next that I should test the fuel pressure or maybe look at the injectors as the problem. I looked closely at the injectors, didn't see any kind of moisture anywhere near them, and don't see anything leaking around them when I rev it.

I went to buy a fuel pressure gauge at my craftsman store, but it said it was supposed to mount somewhere on the fuel rail, so I wasn't sure if it would work on my car. I looked but didn't see that type of adaptor anywhere on my fuel rail.

My tool set is rapidly expanding, but still no running car as of yet. The bright side is that I've been working on it for quite a few weeks now and it still runs. That's somewhat of a shock to me.

 

Yep... thas what it's supposed to do.

Sounds like an injector prob to me too. Pull your spark plugs & make sure all 6 tips look the same.

There is no fuel rail fitting for a pressure gauge. You need to tap into the rubber fuel line before the pressure regulator.

 

Yaaaaaaaaaay!!!!!


Last time they all looked pretty equal. I've idled the car a LOT since I replaced them, good chance they might look like crap again. Maybe I should replace them all again now that I seem to have everything else the way it should be and see what happens to them.



Good to hear, guess I'll have to try an auto parts store cuz sears only had that one type. So I should tap into the line between the fuel filter and the pressure regulator?

Forgot to mention the fuel filter has also been replaced. If I hold my hand on the line coming out of the filter, I can feel a pulsing. Is that normal or should it be steady?



Thanks for your assistance!

 

really? mine just doesn't idle smoothly, like goes between 550 and 750 rpm, but doesn't stall.....i'm so glad me car is back to its usual fast *** self.

 

New update


I bought a gauge that I thought I could use to test the fuel pressure, but as it turns out it doesn't seem to fit. No big deal...however, I was feeling like working on the car and since I couldn't do as I had planned, I decided to pull the plugs. I found five extremely dirty plugs and one that looked brand new. The #5 cylinder was the one that was brand new. A buddy advised me that this probably meant that it wasn't firing, and that it could possibly be a stuck intake valve.

I poured a capful of marvel magic mystery oil in each cylinder and ran the car for a bit, then did it again and ran it some more, then I poured a little more marvel in the #5 cylinder and let it sit overnight. I'm about to go try her again and see if there's any improvement, but I'd definitely call this progress.

One other thing I discovered, it seems my alternator might be shot. I always noticed a difference in the engine when I turned on the lights, but I was concerned with other things, but since I ran out of stuff to do I put the voltmeter on the battery to test it out. It read 14.2 when idling, then dropped to 12.4 after I turned on the lights and a/c compressor while it was running. One more thing added to the list of stuff to fix, but I'm not gonna put the money into that until I get the engine sorted out. The alternator doesn't look that easy to replace.

 

Not 100% true... the car does run, correct? A 6 cylinder engine won't run on only 1 cylinder. What that does mean, is either:
-the injectors aren't spraying correctly
-there is a valve / seal leak
-worn spark plugs
-worn cap & rotor / sparkplug wires

Mystery oil... deffinately sounds like an oil that SHOULD go in the engine

12.4 is pretty low... then again stock 280zx alternators suck! Take it to a local parts store & have them perform a charging system test.