Won't start

[mjr45]

First off, I am totally ignorant when it comes to electrical issues, I can diagnose

most mech issues but electrical, I'm lost. I recently finished a major redo of my

75, put the engine and tranny back in and reconnected all the wiring harness.

Prior to the redo, the car started and ran fine. Now the starter won't spin, the

fuel pump runs, lights work, but nothing else. I do hear a solenoid click, but

its not the starter. The only electrical I changed was the coil. There is a wire

on the passenger side harness with a loop connector that I believe goes to the

starter solenoid with the battery hot wire. I tried disconnecting it and then

nothing worked.There is also 2 red wires from the left firewall with 2

connectors 1 with inline fusable link and 1 without, I know the linked goes to

the hot terminal and "think" the other to a neg ground, I disconnected the

unlinked and everything that worked quit. I took pics of everything before

disassembly for reference and then my computer crashed and I lost all of

my pics, all the ones showing progress and my reference ones. Any help will

be appreciated. Thanx for all the help I've recieved from these forums, you

guys have saved me a lot of time and expense.

[grantf]

can you show pics of the current setup. This sounds like it could be really simple. have you tried a jumper wire from the battery to the starter yet? ( put it in neutral first!). It could be a simple loose conection or dirty contact it happens often that you will get a bad contact after taking things apart, try cleaning all of them.

[mjr45]

Haven't tried the jumper yet, but will try today if it warms up a bit, no heat in the garage and we got 7" of snow overnite and still coming down. I had the starter checked and it spins with the solenoid bypassed, I'm not sure how to check if the solenoid is bad. A new solenoid was $34 and a new starter with the solenoid attached was $29 go figure.

[Zed Head]

Is the small gauge yellow wire connected to the male blade connector on the starter solenoid, and making a good connection?

You can test starter function also, by running a jumper wire from this blade and touching it to positive on the battery (low budget remote starter). If it cranks, you have a problem with the wiring, if it doesn't, with the starter.

[mjr45]

Zed. I cleaned off the blade connector prior to connecting. The starter tested OK and spun up (at Auto Zone) but couldn't check the solenoid. After a lot of searching here, I believe I have all the connections correct, so I'm thinking its either the starter solenoid or the ignition switch. I will send some pics later today.

[Zed Head]

Try the jumper. It will tell you something about whether it's the starter or the ignition wiring. You can also jump directly from the main stud to the blade, using a screw driver.

[mjr45]

Zed, tried the jumper and the starter spun up, engine wouldn't start with multiple attempts and a can of starting fluid! So I'm thinking the problem is with the ignition module (the connector on the back of the ignition)?

[kjohnson2444]

I recently struggled with a non-starting 240z and it turned out that my points gap was so far off that it never actually closed. Readjusted and it started right up. Just a thought. Hopefully it is something that simple.

[grantf]

have you checked all of the conections to the ignition control module I am talking about the module up above the fuse panel on the passenger side (check the ground connection). Also when you jumped the starter was the key in the run position (I know it's a dumb question but sometimes I overlook the stupidest things).

[mjr45]

I had the key in the run position, the engine actually fired a couple of times and tried to run but died out, it ran as long as starter fluid was sprayed into it, I am getting a fuel pressure gauge today, but there was fuel in the lines of the rail. I'll check the ignition module today.

[mjr45]

Today I replaced the starter and the ignition switch still no joy. I jumped the starter and it turned over then the engine backfired and blew the dipstick out, buried it in my garage ceiling! Now I'm totally lost.

[Zed Head]

mjr, you've jumped past what your tests showed and maybe spent a little extra money. When you jumped the starter and it worked, you showed that the starter was OK. You probably didn't need to replace it.

When the engine fired a few times but didn't keep running unless you used starting fluid, you showed that you have spark but no fuel. For a 75 with fuel injection, there are several reasons why the injectors might not fire. You should focus on that as the reason it won't stay running when the starter is jumpered.

When you had the ignition switch apart, you might have tried turning the electrical switch with a screwdriver in the slot (maybe you did this?). This would tell you if it was the electrical switch, the wiring to the starter, or the mechanical part that turns the electrical switch when you twist the key. Basically, break the system down in to what works right and what doesn't.

A basic logical approach works best when digging in to these cars, especially with the EFI engines. Even after you get it running, there will be tuning issues that need a similar approach. Good luck.