Jump to content
HybridZ

280z will not start!


Recommended Posts

ok so bigflatblack and i finally got the ol' 280 running and we took it out for a drive last night. when we get out in the boondocks of central valley country the car dies!. We figure we ran out of gas so we have a buddy bring us gas. we try to start the car and nothing!. it turns over and we have spark and fuel but it will not start. We have spark at the coil and at the plugs and fuel is going to each cylinder and all injectors are working.

 

Im thinking that maybe the timing chain jumped and the timing is off now? Is there any ideas you guys have as to why it wont start? i wont be able to work on it until thursday so i just wanna know things to check out that may take care of the problem instead of taking the front of the engine apart and checking the timing. thanks in advance guys

Link to comment
Share on other sites

to check you timeing w/o tearing it apart, pull the #1 cylinder (front) and rotate the engine with the key off to TDC. You can verify this by taking the Dist cap off and the rotor should be pointing at the #1 plug on the cap. then w/ the cyl at the top and the rotor at #1. then look at the crank, it should also be at 0 degrees +/-. this would mean your timing is set correctly.

 

These are interferance engines so hopefully it's not a timing issue, (unlikely, the chains don't often skip) It's more likely your AFM plug, or maybe a clog in the Fuel filters. Having spark is good. It doesn't try to start at all?

 

Phar

Link to comment
Share on other sites

Yeah that's why I thought it wierd because it turns over ad there's spark but it doesn't try to fire AT ALL. It doesn't even sputter and backfire. And for that to happen the timing would have to jump atleast 180 degrees (wouldn't it?)...and that's unlikely. So I'm thinkin maybe something happened with the distributor?...

 

Also I'm not leaning towards the afm because when I was trying to get it started before when I was having other problems with it (which ended up being water in the tps connector) I unpluged the afm and the car still started but it died right away so that's why I'm not wondering if the afm is bad....

Link to comment
Share on other sites

that could be. maybe upplug the AFM and see if it does anything like before. maybe the AFM is stuck the other direction. If it thinks it's wide open then the injectors would be wide open, if it's stuck closed, then maybe it's shutting off fuel flow. A can of starter fluid could answer this question...

Link to comment
Share on other sites

alright so i got the z home today and started wrenching on it. The distributor turns like it should and its not skipping so im ruling out a broken distributor grear.

 

the timing chain is still very tight on the cam gear so im wondering how hard it is exactly to spin that gear 180 degrees while driving but yet have the chain have no slack in it. Seems impossible to me. The cam gar has all the teeth in it nd they arent scored or anything. so that furthers my thought against the chain jumping and putting it out of time.

 

i took off the afm and tried putting starter fluid in it and the same thing happens.

 

i did notice though that theres a little box underneath the coil that clicks when the key is on (like if u leave it in the accessory switch or whatever) and it sounds like there is also a clicking sound that happens somewhere in the throttle body or maybe one of the injectors.

 

this little box that im talking about also seems pretty hot to the touch. Im not sure if its normal or not so maybe some of you could help me out. if this has ANYTHING to do with it not starting?

IMG_01391.jpg

 

sorry for the crappy quality but i have to use my phone to put up pictures.

 

on the very right hand side the nut on the terminal that the wire connects to is very hot also. Again i dont know what this box is or if its normal for it to be hot or for it to have some kind of clicking sound kinda like a relay or something.

 

so if any of u could help me out id gladly appreciate it!

Link to comment
Share on other sites

The little box is the power resistor for the coil. It is supposed to get pretty hot. Now if it has good cam time, good (timed) spark and fuel, it's going to run, or at least try, -period-. One of them is completely messed up if it isnt even trying. Since you have already cranked it after this started, assume the cam is OK. Does it smell like gas at the exhaust when you try it? If not, then you dont have fuel. Check the fuse and power for the injectors. Each inj should have 12V on 1 pin when switch is set to run. Check spark with a timing light. Any number of things can go wrong inside the distributor. If it's the cam, you've already torn stuff up in the engine most likely, but take the valve cover off and look for a broken cam ( only the front part of the cam turns w/ the engine cranking) or a sheared index pin If the jesus bolt on the cam is loose, the cam will BEAT on the pin until it spits it out - the whole cam wont turn then, just the gear - but the chain will still look tight.

Link to comment
Share on other sites

The little box is the power resistor for the coil. It is supposed to get pretty hot. Now if it has good cam time, good (timed) spark and fuel, it's going to run, or at least try, -period-. One of them is completely messed up if it isnt even trying. Since you have already cranked it after this started, assume the cam is OK. Does it smell like gas at the exhaust when you try it? If not, then you dont have fuel. Check the fuse and power for the injectors. Each inj should have 12V on 1 pin when switch is set to run. Check spark with a timing light. Any number of things can go wrong inside the distributor. If it's the cam, you've already torn stuff up in the engine most likely, but take the valve cover off and look for a broken cam ( only the front part of the cam turns w/ the engine cranking) or a sheared index pin If the jesus bolt on the cam is loose, the cam will BEAT on the pin until it spits it out - the whole cam wont turn then, just the gear - but the chain will still look tight.

 

Ok.....yes the tail pipe does smell like gas when trying to start it. ill check the fuse and power for each injector. i do know that i used a test light to see if they were getting power and it indicated that they were but that doesnt mean they were getting enough so ill check that out. the cam spins when trying to start the car because i took the valve cover off and turned the car over and it spins like it should. im just going to have to get a timing light and see how off the timing is.

 

the question i have about that though is.....is it possible for the timing to jump THAT much in the middle of driving it?

 

it was starting and running perfectly once i got the new battery and then just cruising down the road it lost power seemingly for no reason.

 

so idk im pretty stuck on this and ill check out the timing and the injectors once again

Link to comment
Share on other sites

Well if the cover is already off, check the cam time too. Turn the engine over by hand until #1 is at TDC (0 deg mark). Remember the 0 deg mark is also BDC ( #6 firing )!! If the cam lobes are pointing upwards on the #1 cyl at 0 deg, then thats TDC. Now check the timing gear. Look for a notch on the back side of the gear - not out by the teeth, but in close to the cam tower just behind the gear. The notch should be very closely lined up with an identical notch in the cam tower. As I recall it is slightly toward the passenger side of the car. That will tell you how close your cam time is.

 

Next, how did you check spark without a timing light? Have you checked the important ignition connections, like diz to harness, harness to brain box, etc.? I dont know exactly what is there, mine is a 74 260, and I've only had it a month, but it has taught me to never trust ANY electrical connection without checking it. Are the plugs fouled? On mine the diz harness runs right past the AC belt. Any problems there?

 

What is the recent mechanical history? In other words what have you been working on recently, or what has changed or acted up recently?

 

Sorry to go on so much, but it's not easy troubleshooting something you're never going to see!

Link to comment
Share on other sites

the question i have about that though is.....is it possible for the timing to jump THAT much in the middle of driving it?

 

The timing chain has a tensioner to keep chain tight. It has a spring that after time may get weak but I doubt that your chain jumped any teeth. You most likely would have heard it. How does the cam gear look ? if it jumped any teeth it would cause damage to the cam or crank gear teeth. have someone turn the engine over slowly and watch cam teeth and look for damage on both sides.

Did you hear anything before it died ?

Are the plugs fouled ?

were you hard on it before she died ?

What about air filter ? no air no fire

just a few things to check. Good luck

Link to comment
Share on other sites

the question i have about that though is.....is it possible for the timing to jump THAT much in the middle of driving it?

 

The timing chain has a tensioner to keep chain tight. It has a spring that after time may get weak but I doubt that your chain jumped any teeth. You most likely would have heard it. How does the cam gear look ? if it jumped any teeth it would cause damage to the cam or crank gear teeth. have someone turn the engine over slowly and watch cam teeth and look for damage on both sides.

Did you hear anything before it died ?

Are the plugs fouled ?

were you hard on it before she died ?

What about air filter ? no air no fire

just a few things to check. Good luck

 

I was kinda rough on it before it died. not Right before it died though and i never reved past 5000 i dont think (if thats considered to be rough, im not sure)

plugs are not fouled they are brand new and gapped properly.

it is sucking in air like it should

 

The cam gear has no score lines or broken teeth on it either.

i checked to see if there was spark by the old fashoned way of putting a screwdriver in each plug wire and arcing it on the side of the car somewhere.

 

i just went out and bought a timing light so im going to check the timing with that and see what happens.

Link to comment
Share on other sites

Are your plugs wet with gas???????? If not, you have a fueling issue. This sure sounds like a fuel pump took a dump. Another thing. If your plugs are fowled with gas I have had a fuel pressure regulator on top of the fuel rail stick, flooding the car out. Pull the vaccum hose off and tap on the regulator. If you can get it running again then that is what is wrong. Not a common issue but it does happen 1/100 times.

Link to comment
Share on other sites

hmm ill have to check out that regulator once it get light ouside. Also going to check the timing and see if the number 1 piston is at tdc in unison with the valves being closed and the distributor cam pointing at the number 1 cylinder.

 

if that all checks out and everything is fine.......well then ill be back here picking everyones brains some more......

Link to comment
Share on other sites

  • 3 weeks later...

alright everyone.

 

Im somewhat ashamed to tell you what i had to do to fix the problem with my Z.

 

If any of you have read the back story to this then you will be pleased to know that i have the Z on the road again.

 

I went through everything trying to find the problem. Thought it was the timing at first. Thank god i didnt try doing anything with the timing yet. lol

 

Then i thought it was the afm or some stupid sensor that likes to go out.....it wasnt that.

 

I was HOPING it wasnt a burnt out ecu or something like that.

 

So after a few weeks of not being able to work on it i finally made time today. MY grandpa told me to check and see if the fuel pump was turning on or not. so i crawl under the car expecting everything to be fine but i was going o humor him anyways and check. I was positive that it wasnt a fuel problem because i could smell a bunch of gas coming out of the tail pipe. Turns out that that was just the remaining fule left in the lines.

 

So anyways i crawl under the car and i see a wire that comes from the fuel pump just hanging loose and a connector attached to another piece of wire going to the front of the car. As soon as i saw that i said "oh Sh**" because i knew that would fix the problem. Sure enough it did.

 

So two lessons learned today.

 

NEVER trust a cars wiring job unless youve done it yourself and know its right.

 

And also........Wisdom comes with age no matter how much us young guys want to admit it and think we know everything. Theres always an older and much wiser guy out there to help out as long as you are just willing to listen.

 

thanks all for the help.

 

Now on to planning future mods again!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...