The latest in my car WONT START saga

[MEZZZ]

I am a novice at best at this and I have been doing alot of reading both online and via the FSM and F.I. Manual. I am trying to track down the reason my car will not start.

To recap to date, I have replaced the following, fuel filter, spark plugs, wires, dist. cap and rotor, ignition coil, injectors and connectors, fuel pressure regulator, battery and every visible vacuum hose and injection hose I could find. The car started but ran poorly before I changed out the fuel filter, plugs, wires, cap and rotor. It still ran poorly afterwards. I pulled the A.F.M. to clean/check connection and after that, I cant get it to fire, just crank.

I tried succesfully to get it to fire using starter fluid. I have juice at each plug and the fuel pump runs when I pull the wire to the solenoid. I can hear the fuel pump run and the new fuel pressure regualtor kinda hiss momentarily and make a slight buzzing noise. I have not performed a fuel pressure test but when taking the fuel line off past the filter, it came hissing out telling me that I at least have to have some type of pressure.

Therefore I am thinking the problem lies somewhere electrical in nature concerning the injectors. I found the fule injection relay under the dash and after my brother changed it around thinking I had it plugged in backwards, i figured out the correct way and corrected that. Still would not fire.

Tonight I got the manual and did the fuel pump check as outlined in the car wont start part of the FI manual and it checks out. My next step was to check power at the relay. I used a test light vs. a multimeter and at the fuel pump relay, testing the connector with the key set at the "on" position, 3 of the wires are hot. I am thinkiing that is because as you turn the key to start, it fires others and then diverts some to the AFM when the key returns to "on".

The problem is this. I tested the connector for the power relay with the key on, touching all connectors, I get no light. Then I tried each again while cranking the car and still got no light. Like I said, I am a novice to this, learning as I go but think this might be a problem

Can someone (sblake01 perhaps) guide me as to what to do from here? Fusible links coming off the battery going into the injection harness? I tried testing the positive one at the connector and it arced pretty good when I grounded it. Is there anywhere else I should look?

I have read the FI manual and have not yet started testing all the connectors at the ECU. I pulled up the FSM for a '77 last night and to be honest, got a little lost. As always, any help is appreciated.

[sblake01]

I don't think that most people realize the the 280Z EFI Theory and Troubleshooting manual, sometimes referred to as the "EFI Bible" for whatever reason, is pretty much geared to the 75 280Z and many of the functional tests outlined in it will not give proper results for other year 280Zs and 280ZXs etc. Since your's is a 77 the best thing to do is go through the steps outlined in the 77 FSM from page EF-18 in the Engine Fuel section through the end of that section. Everything prior to page EF-18 in that section is just description of the system and how it works. EF-18 and on is about fixing it. That's some 50+ pages of reading but it's the only way to find out what's working properly and what isn't. In those pages you will find all of the troubleshooting info, component functional tests, 26 pages of the individual circuit tests, etc. All geared to the 1977 280Z. I know it can seem overwhelming but it's the only way to get to the root of what's wrong.

[MEZZZ]

Thats not the magic answer I was looking for here Stephen

I was hoping you would say...Oh, trace the white/blue wire and plug it in and your done

Well, I am off work next week, my wife is not, my son is going to daycare, so I have 5 days, 8 hours each to read and figure this thing out.

Thanks as always.

[sblake01]

Sorry. I more or less went through the same thing when I bought my 78. Tried to troubleshoot it with a manual that wasn't specific to the 78 and though some of it worked, I wasn't able to get it right until I followed the 78 troubleshooting instructions. There are subtle differences between the four years of 280Zs. Like the fuel pump circuit, relay type and location, fusible link type and location, etc. I wish I did have that 'magic answer'.

[Rockr69]

I pulled the A.F.M. to clean/check connection and after that, I cant get it to fire, just crank.

It seems to me, there is your problem. If it ran before and not after start over at the problem.

[sblake01]

His car should have that feature. 77 was the last year for fuel pump contacts in the AFM.

[MEZZZ]

It seems to me, there is your problem. If it ran before and not after start over at the problem.

I wish it were that simple Believe me, the AFM is the first place I looked!

I had taken it off soon after buying the car when I was doing some major cleaning of the engine compartment. I really wish I had taken before and after pictures, its amazing what a couple bottles of degreaser, some scotch brite pads and 5-6 hours of time will do.

Anyway, not long after I originally pulled it to clean, I noticed it missing a bit. I pulled it back off thinking I forgot something but the connection was tight and the ground secure. I did wipe inside the chamber and at that time, checked the flap for fluid movement, which it had.

A couple weeks ago, after replacing plugs, wires, fuel filter, etc, I couldnt get it to start. Thats when I noticed the tank almost on "E". I got a gas can and bought a couple gallons of fuel and dumped it in and got her to fire, although still running rough. Thats when someone (maybe Stephen) suggested I look for cracks in the AFM boot and make sure the connections were clean.

Thats when I couldnt get it to fire after doing that. I went back to the AFM first. The connection is tight and I even sanded the metal where the ground is to ensure a good connection, still nothing.

Can either of you guys tell me one thing? Should I have power at the relay with just the key on? I used a circuit light and got it to light up on the fuel relay but no light on the power side. I have to start at that point I am thinking. I believe that relay gets its power directly from the battery via the fusible links attached to the battery cables, then sends power to the AFM from there once the key is in the "on" position.

You are correct Stephen. I noticed the F.I. Manual would refer to the 1975 FSM "page whatever". I do have the one for a '77, its just a matter of time and patience and learning. You guys are definitely a big help as well.

Thank you

[sblake01]

Can either of you guys tell me one thing? Should I have power at the relay with just the key on? I used a circuit light and got it to light up on the fuel relay but no light on the power side. I have to start at that point I am thinking. I believe that relay gets its power directly from the battery via the fusible links attached to the battery cables, then sends power to the AFM from there once the key is in the "on" position.

From the way I understand how the cars with fuel pump contacts in the AFM work (75-77), the only way you would see power on the output side of the relay with the key in on position and the engine not running, would be to manually open the flap in the AFM.

[MEZZZ]

Thanks Stephen, I will give that a try tomorrow, I appreciate the reply.