'76 280 Still not starting???

[Chris'sZ]

About to pull what little hair I have out!

Thinking I was having alternator trouble I pulled the positive battery cable off and she died...and...has not started since??? I have spark at the plugs and fuel into the cold start valve so I'm assuming fuel to the injectors also. After sitting for a bit, she will "fire" for about 2-3 seconds then nothing.

Any help or Ideas on what to do next will be greatly appreciated...

Chris

[racebird1]

If It died when you pulled the cable then you can be sure you have some sort of a power problem. Charge up the battery and try to disconnecting the altenator. It should run on battery power alone at least for awhile, but it needs a good charge. There may be a shorted component somewhere.

[KDMatt]

I have ... fuel into the cold start valve so I'm assuming fuel to the injectors also. After sitting for a bit' date=' she will "fire" for about 2-3 seconds then nothing.[/quote']

I personally would not assume that the injectors are firing just because the cold-start is. They operate on different circuits and are designed for different things.

The description you give makes it sound like your injectors are not, in fact, firing.

The couple of seconds for which it does run might be due the squirt of gas from the cold-start, and a lack of fuel from the injectors.

Try taking a multimeter and hooking it up to a connector for one the fuel injectors. Unless I'm mistaken, you should see it spike repeatedly as you (or a good friend) crank(s) the engine (I think it's somewhere close to 3 volts?). If you get no reading from the injector connectors then you for sure have an electrical problem. If you do get a reading, then you might be dealing with a fuel delivery issue.

[Chris'sZ]

Thanks for the replyz...I will try these suggestions and let you know.

Thanks Again...

Chris...

[sblake01]

Thinking I was having alternator trouble I pulled the positive battery cable off and she died...and...has not started since???

I've been looking at this thread and your other versions of it and that statement always bothered me. First of all, I dislike the thought of disconnecting the battery while the engine is running. That has never sounded like a wise move, to me. Then it dawned on me. You pulled the positive cable. So, as the engine was dying, any residual current ran through the system unabated/unregulated. If you're ever going to disconnect the battery for any reason, engine running (!) or not, pull the negative cable first (and reinstall it last). I don't know what you zapped/fried by doing that but obviously you did something. If the car ran before you did that and it doesn't now you can rule out fuel related stuff. There are many electrical components in the EFI system and all you can do at this point is careful step by step troubleshooting. Any ideas I could give here would be purely speculative.

[beandip]

Just another thought. You stated that she will start and run for a second or two. I don't have experience with the key switch on a '76Z , but on a 240 the switch has two detentes on at the start position and another in the run position. Just wondering if this could be a cause. Another thing as sblake01 stated you could have likely fried something by disconnecting the battery as you did. I am running a '80ZX ignition with the 12-80 module and I know they are sensitive to surges in the electrical system. Your ignition has a module of some kind , different from mine and this may be something to look into. Have you sent a email to Kim Blough ? smokeyyaro@veloscitus.net This guy is the most knowledgeable Z person I know on this stuff. Gary

[KDMatt]

I don't know what you zapped/fried by doing that but obviously you did something.

Chris, there is an EFI Manual (available online in pdft format) that tells you about every electric circuit in the system (including a wiring diagram) and this is a fabulous place to start. There are many mentions to it on these forums, but if you still can't find it, let me know and I can send it to you.

Included are step-by-step circuit tests which are really not hard to do at all.

The best of luck sir!

[Chris'sZ]

Thanks for the replys guy's...I would appreciate a link to the EFI "Bible". I know I have seen it posted before but not sure where to start looking. I also hope I havn't fried something major. It was a "mecyhanic" friend of mine that pulled the cable off...Don't thinl I would have ever done it.

Any way...tyhanks for all ya'lls help...

Chris

[sblake01]

Here's the EFI Bible:

http://www.atlanticz.ca/zclub/techtips/efisystem/280zfuelinjectionbook.pdf

Since you have a 76, this might also be of use to you:

http://www.atlanticz.ca/zclub/techtips/76sb/1976_280z_S30_Service_Bulletin.pdf

[Chris'sZ]

Thanks Stephen...Down loading now.

Chris

[280~Master]

This does not sound like a fuel problem.

I would start with the basics. Check your fuzes first of all and make sure you did not blow one with the battery trick. Then see if you are getting spark to the plugs. If so then test your fuel to the injectors. If you got fuel to the injectors and spark to the plugs then you have a problem with something major.

If you have no spark to the plugs, check your coil and distro to see if they are working.

If there is no fuel to the injectors start with checking the fuel pump to see if its even coming on. You should be able to hear a humming sound coming from the passenger rear wheel. If you have no fuel and hear no humm then your fuel pump may just have gone out.

Good luck andd keep us posted of your progress and solution.

[Chris'sZ]

Thanks John. I'm reading the EFI "Bible" which I think will be very helpful. It rained here all day so no chance to work on her today. Hopefully tomorrow (today) will be better. Thanks for your reply and I will keep all posted

Thanks Again,

Chris...