Newer user in Cincinnati

[Mezzz]

I found this site awhile ago when I bought my 1977 280Z but somehow forgot to save it to my favorites list! Well, I found it again today and it has been saved right at the top of the list.

I bought my Z on Ebay last fall (long, sad story) and have been slowly but surely trying to get it back up to the condition I hoped it was in when I bought it. I have only seen 2 1st generation Z's on the road in the past few years here so I had to go out west to find one...BTW...any Cincinnati members on here? I would really like to meet some fellow enthusiasts!

I've had a heck of a time getting it to start and I'm in the process of reviewing the Fuel Injection manual in hopes of tracking it down. She ran fine when I bought her. I didnt drive the car much as the P.O.(S.) took 2 months to get the title to me(another saga in the Ebay story). I let it sit a week here and there without starting, it started missing and then finally wouldnt fire up.

I did the stupid and expensive thing by starting to replace components. I figured they needed repalcing anyway as most looked to be very old, worn and filthy. I put on new Taylor Hi Pro wires, correct NGk plugs, rotor and cap. Replaced the small ignition coil (held in the bracket by a wood shim!) with a MSD Blaster 2 coil. I then replaced every vaccum hose and the PCV valve. While I was in there I figured I might as well replace the fuel injectors and connectors (connectors were cracked and loose) and I put on a new fuel pressure regulator while I was there. Replaced all the fuel line with injection hose and clamps.

I finshed with all this yesterday and when I went to start it up...it just cranks. I can get it to start for a second using Starter Fluid. I checked for spark and have it at all 6 plugs. Next on the list is a fuel pressure test. I thought it might be a clogged gas line/tank but I wired the fuel pump direct and have gas and I can hear the pressure regulator.

So its on the the Injection manual to try and figure this out. I have also cleaned as many connectors and grounds that I could see. I am thinking it might be the fuel relay, A.F.M. or the E.C.U at this point. I've looked at every wire and hose, looking for a missed connection.

Regardless, sorry for the long intro. I look forward to any advice/encouragement at this point as I am getting a little discouraged right now ! Any Cincinnati/Northern KY members on here, I would like to hear from you.

[Daeron]

Welcome, and thanks for doing your research before posting the questions!

 

Pull a spark plug after trying to start her and see if it smells like gasoline.

 

To be honest, it sounds like the only un NEEDED expense you have gone to thus far was to install new injectors, and that isn't such a horrible thing. The primary problem with that is, once you get a few steps down the road and get hungry for more power, somewhere along the line you will want to be buying larger injectors, and now you will be replacing nice, NEW stock sized ones instead of the leaky originals. The connectors, plugs, wires, vacuum hoses etc are all important to change ANYhow.. so don't beat yourself up for "throwing parts at a problem" yet.

 

Have you pulled a spark plug out of the engine, and visually inspected the spark coming out of the plug? I like to do that on a no-run or poor-run situation when I have virtually no data to go on; it is good to see bright, blue spark come out of your plug, and once or twice I have done this after beating my head into a wall and seen yellow spark coming from a perfect ignition system, with beautiful, 20K old NGKs.. that needed to be replaced. You never know where a weak point in ignition might come up, so its always nice to see that blue spark there where it NEEDS to be.

 

Fuel pressure, timing check, vacuum leak check.. do you have the FSM handy to check for vacuum line diagrams? They are available through a website that was linked to in a recent thread in this subforum..

 

Sorry to be a little vague, but we ARE kind of beginning at square one here Good luck!

[Mezzz]

Thanks Daeron for the advice and words of encouragement. You are right on the injectors. I found them on Ebay and they looked like a good deal. They are reconditioned, check out the link and let me know what you guys think. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&viewitem=&item=190231310169

 

On the spark plug isssue, no, I havent pulled one since replacing them. I did use a "go between" test light on each plug and it registered current. I will try to pull one per your suggestion and arc it.

I do have a F.S.M. on my hard drive and I printed out the 280z Fuel Injection Theory and Troubleshooting manual yesterday, hole punched and in a binder now. The F.I. manual will be a great place to start, very well written and fairly easy to understand.

[Guest dat73sun]

hey what part of cincy are you from? Im from the outskirts out west around batavia. Im in Cali for now where im on my second 240z. I love the car! ive driven muscle and imports but something about the endless possibilities for this car keep me glued! am i wrong? any ways if you need advice on things you are definitly in the right place! good luck with the build man!

[Mezzz]

I'm not too far away from Batavia , Anderson Township (Beechmont). Thats why I havent seen a Z around, you moved

 

Thanks for the well wishes, I have a rare week off starting tomorrow, my wife does not, I have to pay for daycare whether my son goes or not (so he is going), so I have 5 days to do nothing but work on this thing!

So, you ever coming back this way?

[Daeron]

Don't forget to pull a spark plug after attempting to crank and see if it smells like gasoline, it may be getting drenched which is the exact OPPOSITE of no fuel, but still equals no start. Somehow, though, I get the impression you are noticing a lack of fuel rather than an abundance.

 

So, just for clarification.. Are you getting fuel flow to the rail when you crank it, with the pump wired "stock?" I am going to assume no. Have you tried to start the car with the fuel pump "hotwired?" If you haven't go ahead and do that; it sounds like You have confirmed fuel flow with the pump hotwired. If it runs like that then you've definitely got a fuel pump power issue, and those can be FUN to track down.. but usually are fairly rapidly traceable to a failed component or broken circuit somewhere. (AFM, relay, or wire associated with either, or wire associated with ECU..)

 

If you have ample fuel flow and correct pressure with the pump hotwired then I would try re installing the stock coil, or examining the installation of the coil again. Check firing order, eyeball the stupid stuff that everyone misses once in a blue moon.

 

It NEVER hurts to take the rubber hoses off of the hard fuel line and blast everything out with some compressed air.

 

 

 

If you DO find you are experiencing an "over-fuel" situation, the processes of diagnosis and troubleshooting are entirely different; you either have a bad regulator or one of the electronic components of the EFI system is malfunctioning with the result of far too much fuel enrichment.

 

There really aren't TOO many problems it could have.. My brother once complained to me that it was so overcomplicated and over-engineered, but I couldn't disagree more. (He was possibly just expressing a frustration at the antiquated design?) It is such a simple system that, as daunting as it appears, some time studying the manual and patiently looking at the real thing in front of you is MORE than enough to really grok the entire affair in fullness. (Do you grok "grok"? If not, google grok. Then the preceding two sentences will make sense )

 

Good luck, and don't hesitate to ask questions along the way.

[Mezzz]

Thanks for the info Daeron. An update on this issue.

 

I have pulled a plug per your suggestion, yes, I get a nice spark and no, it was not wet or smell much like gasoline. I have in the past, hot wired the fuel pump and it did run and pump fuel to the rail. I could hear the pressure regulator as well but it still would not fire. Per the F.I. Manual, I did pull the wire off the solenoid and verified the fuel pump is running when I turn the key to on.

 

I could not get the car to start before I changed the ignition coil either, so I dont think it could be the culprit. I just changed it out because the old one was too small in diameter and the P.O.(S) had a piece of wood shim holding it in place

 

I am leaning towards an issue with the ECU or AFM or possibly the injection relay. I bought a circuit tester and checked the 2 plugs going to the relay under the dash. On the fuel pump relay connector, I have power on some of the wires, which kinda make sense as I believe the switch once the ignition goes from run to on. I had no power to the power relay connector when I checked any wire, either with the ignition turned to run or start.

 

To recap, it ran well when I bought it for a short time and started to run rougher. Going through my mind, about the only things I did between buying it and the rough running condition was clean up the engine bay. I used ALOT of Simple Green and thought at the time maybe I sprayed some connection as it got better a couple days later, then started missing again.

 

A couple weeks ago, before replacing items, it ran rough. After replacing wires, rotor, cap, fuel filter and plugs, it ran about the same. So I pulled the AFM to clean the connector and then I couldnt get it to fire after that. Logic would say the issue lies somewhere in that but I can see anything out of place, ground is clean, plug is tight and I did check the flap for smooth opening as well.

 

I downloaded the F.S.M. awhile back and printed out the "EF" chapter Saturday, I have begun reading and trying to make sense of it all. Thanks for the tips!

[m4xwellmurd3r]

what's the resistance value of your water temp sensor. If by some odd chance, that wire breaks, the car won't get any fuel and won't start. A continuity test at the ECU will find that out real quick

if you think your AFM is the culprit, just unplug it. the car will run without it, but the idle will be all crappy and pulsate. if that doesn't do anything, you can rule out the AFM being the issue for the most part. Another thing, is see if your injectors are actually firing when you crank it. a simple test light will do this. it'll blink if the injectors are pulsing at startup.

[DuoWing]

These cars will run with the AFM disconnected? One time when I replaced my radiator, I disconnected the AFM and removed it to get to one of the radiator mounting bolts better. I got everything back together and the car would crank and crank, but would not start. I eventually found out I hadn't plugged the AFM back in.

 

I was initially going to say maybe the ignition itself is shot. That was the only thing you didn't change, but you have blue spark up at the plugs so I'd say you're probably ok on that end. One thing you need to do is a fuel pressure test. If the fuel pressure regulator failed, it could be stuck open allowing all the fuel to go straight through to the return line and not actually build up enough pressure in the rail. You should also hook up a multimeter to the injector connectors and have someone crank the car while checking to see if a signal is getting to the injectors. Also as said, check your water temp sensor. These always go bad. They're just old and it's about their time. Anything that is small has a thermistor and is constantly heating and cooling is bound to fail after 30+ years.

[Daeron]

Multimeters canb be had for 5-10 bucks at harbor freight. They aren't the greatest (they really stink TBH but at that price they're practically disposable) but you pretty much NEED something to track this down. I am imagining a stuck open fuel pressure regulator is a possibility as well, try pinching the return line off with your hand mostly and see if it will fire like that, with the pump hotwired.

 

It seems that the pump control circuit has been verified non-functional. That is not uncommon, and you seem to be on the right path to track that issue down, but there are definitely two distinctly different things wrong with it, and a bad relay probably would not cause this gradual puttering out.. I would concentrate on the AFM issue you noticed to a degree as well, and the coolant temp sensor wire as mentioned above.

 

You should be able to find component tests for all of these things in the manual; it is important to conduct the component tests for the CTS and the AFM both AT the component, and at the ECU wiring harness. Testing the function of the unit at the ECU plug also tests the wiring associated with the unit. If a component tests fine at its own terminals, but doesnt test the same at the ECU terminal, you know you have found a bad wire (I like to call 'em "magic wires" because they usually come and go like little gremlins..)

 

In any case, it is extremely difficult to troubleshoot these areas without a multimeter, and rather easy to do so with one. using the meter is fairly easy to pick up, too, and I can help with that if needs be. Blue's techtips page has a link to "common electrical testing procedures" i think....

[Mezzz]

thanks again for the replies. I had someone stop by yesterday ans we went over a couple things. Pulled the #1 plug and he told me the spark is weak. I have brand new plugs, wires and MSD coil. He told me to replace the pick-up coil in the distributor.

I have a multimeter Daeron and will perform some test. I also have a fuel pressure guage and bought a noid light last night for the injector test, so you guys are right on track with me on my next steps...I will post my (hopeful) progress

[Mezzz]

Mystery solved! I had what looked like speaker wire or lamp cord (clear insulation/2 strands, one copper, one aluminum) running from under the dash around the ECU. It ran under the driver door and disappeared behind the vinyl panel where the stock speaker was mounted. I discovered this wire a few months ago when gutting the interior. I figured it was some hack job going to the stock speaker, although it was wire nutted off. All these months, I left it hanging figuring eventually, I would remove it.

Last month, I rolled the car out of my garage, either to sweep the floor or maybe one of my many attempts to start it. I had the mystery wire hanging out and had rolled over it and the wire broke ff at the door.

This week,I switched directions for a couple days and decided to install my Speedhut overlays. While at the dash, I decided to trace that mystery wire and get rid of it. It ended up, once I removed a BUNCH of tape, spliced into the harness coming out of the ECU and bridged into the connector attached to the ignition switch.

Could that be my problem? I took a couple pics and with the advice of a trusted guy from another site, we figured out the P.O. must have at one time, had a kill switch installed. There is about 1/2 diameter hole down low on the panel with the speaker holes in it, probably where the kill switch was mounted. Anyway I twisted the wires together and she fired right up!

Thanks Daeron for the advice, I can now go about installing the new pick-up coil, setting the timing and doing a compression test, etc.

[WizardBlack]

Sounds like you are starting to make your way through the car. I live in Columbus and have a '77 280Z that I bought from a guy a stone's throw from King's Island. The wiring, sensors and (especially) AFM on these cars are pretty much toast by this point. I replaced pretty much 100% of the wiring in the car including battery/alternator, fusible links, ECU/Engine, Dash, etc. A lot of it was waiting to fail TBH.

Anyways, shoot me a PM if you want contact info. I've been through a lot of stuff on the car and continue to do stuff. I have a Megasquirt in mine now and a turbo conversion that I am fabbing together. Anyways, it's always good to know other Datsun guys within a few hours, etc.

[Z32Dreamer]

Congrats! on getting your gremlins sorted out... Get that thing over to the shop so we can get it all welded up and ready for paint...

 

jon

[Challenger]

Did you ever try flipping the switch? Maybe it was just in the kill position..

[Mezzz]

Congrats! on getting your gremlins sorted out... Get that thing over to the shop so we can get it all welded up and ready for paint...

 

jon

 

Jon,

Didnt know you were on here. I still have ALOT of gremlins to sort, just one less now. I am hoping to get it up to you in the next couple weeks to weld up. I have the frame rail from Bad Dog and it looks very nice.

 

Right now, I have the dash apart putting together the gauge faces I got from Speedhut. I am about finished with them, then I have to put on a dash cap and mount the new steering wheel.

 

I am still having some motor problems, still seems to be missing and smoking a bit, hopefully once I get the pick-up coil installed and check out the timing, I can get those worked out.

 

Paint probably wont be until next year at this rate, but I need that spot in the floor repaired so I can get teh interior finished up. I will call you when I am ready. Time(as always) is tight but I am off the week of 8-11 and hope to get it up to you then.

Mark

[Mezzz]

Did you ever try flipping the switch? Maybe it was just in the kill position..

That would have been too easy. The switch had been removed long ago with just a wire nutted off and tucked up behind the panel in the dog leg area. It was typical case of doing too many little things at once and not tracking what I did so I could retrace the steps.