Going to try to keep this short as I can.
[[[Motor won't start.]]]
So my motor can crank forever but will not start!! When I turn the key it doesn't crank at all, all that happens is I can hear the fuel pump turn on. Ignition switch could possibly be bad but I doubt it, and it doesn't matter. Keep reading.
When I manually jump the starter by applying a positive current to the solenoid, it just cranks and cranks but never turns the motor over. That's where it gets weird, because it should absolutely start when jumping the starter.
So I thought maybe it's the alarm, so I bypassed the factory security by disconnecting the 8 and 20 pin connectors from CPU#2. Did nothing for me.
I am getting spark. And I can hear my fuel pump running.
I've tried de-flooding the motor even but it's not that.
What the hell can it be?

What should I test for next? And if there are very knowledgeable people out there, then:
Please explain the full sequence, the step-by-step process of what goes on from the moment you put your key in to when the motor fires up.

Thank you everyone in advance and hopefully we can get this figured out.

 

Did you just finish undergoing some mods or did this just randomly happen?

There is obviously an electrical issue, probably something not grounded which would explain the starter not working on ignition-on. There are probably other things not grounded as well.

I you check all that and are 100% CONFIDENT that your grounds are good (meaning you have checked continuity in the circuit with a multimeter at each ground) then start looking into other things.

Check for spark. Pull spark plugs, clean off, re-install except for one. Have someone turn the car over (because your starter/electrical issues will be sorted out at this point). Ground the threads to the chassis and watch / listen for spark. If you have spark great, move to fuel.

Pull another plug. Is it wet with fuel? Yes? Good.

If no spark or no fuel, go to FSM trouble shooting. It outlines exactly what steps you need to do to resolve the issue.

If you have all that but still not start, it is probably flooded. There are several de-flooding threads on this board. You may need to pour a little 2 stroke oil into the plug holes

Sounds like a ground though.
Is the car auto or man?

 

OK, this is a little confusing. When I hear "it cranks but won't start" that means the starter is turning the motor over at 250 RPM but the motor isn't catching and running. Is the motor physically turning?

Or is the starter just spinning (high pitched sound) without the motor turning over?

If it's #2, it's probably the starter. Or the motor is physically locked up or something.

Dale

 

DaleClark: Hey Dale, happy to see you once again jumping on my issues to help out. Yes when I jump the starter the motor turns, but does not turn on. Crank and pulleys, everything turns, but it just keeps turning without a sign of even sputtering or trying to start up.

Mitchocalypse: Happened out of the blue, well, almost.. I'll detail in the next post.
So you're telling me to pull up the wring diagram and go through every single ground wire and check it for continuity?.. Grounds are good. I check each main ground to make sure it is properly grounded and not corroded at all. Also the starter IS working. It just doesn't work from the switch. Again, when I hotwire the starter, it turns the flywheel/crank.
I've checked the plugs and they have spark.
I have the key to 'ON' then I go and manually hotwire the starter while holding the plug to the strut bolt and I have spark. New plugs too.
And READ man!! You can't help out if you have not read my post. I have spark. Fuel pump is running, and I did the DE-FLOODING procedure on multiple occasions.
Car is MT.
And where in the FSM do I find troubleshooting? I just looked over the FSM again and I cant find a section where it outlines troubleshooting.. Although I feel like I've come upon it at some point in the past? :?

 

So basically this happened out of the blue, not following any sort of mod or any change at all.
This same exact scenario happened before as well, about 2 years ago, but the problem resolved itself...
2 years back, I just got my motor rebuilt, put my car all together, and this BS occurred. At first it started fine, but then after about a week, it went to this problem. Ignition switch does not send signal to the starter, and then when I would try to jump the starter manually to get the motor fired up, it would still not turn over. It would just crank and crank, spinning the flywheel & shaft, but would NOT fire up!!
Then after trying it again and again over the next few days, it magically fired up. But ignition switch would not work half the time. But this time, even if the ignition didn't trip the starter, it would still fire up if I jumped the starter. So ignition switch - no work, but hotwire starter - works. Then the problem resolved itself and the car worked fine for 2 years...

Now the problem comes back and AT FIRST for a few weeks, the car would give no signal to the starter when trying to turn on the ignition with the key. But when I hotwired the starter it started up. Sometimes right away, sometimes it would take up to 10 or more tries. And now it just wont turn over period, no matter how many times you try to jump the starter and crank it.

 

I recommend checking your voltage at battery before and then during cranking. Why? Because flat out, the factory starter wiring through the fuse box is absolutely horrible and has loads of resistance in old age. This may not or may not be the issue, but you'd be pleasantly surprised at how much faster any and every FD will crank with a large 0 gauge wire directly from battery to starter. I could not get my 20b to start, brand new rebuild, spark, fuel, all the nine-yards. Just cranked and cranked on 2 gauge battery wire through factory fuse box. Routed a 00ga direct to starter, picked up 100rpm on cranking, fired instantly. Before the wire, my voltage would drop from 12.6v to below 9v on cranking. After, it stays in the 11v range during cranking. Elliot White recommended this wire replacement and he was correct. Had the same issue on an S2k build with battery relocation. Crank crank crank crank. Ran a 00 gauge wire, boom fires instantly.

You've already stated it, but make sure you have spark on every single plug. Pull the lower two plugs and crank with de-flood procedure (pump off) to see if you hear even compression. If you're getting fuel, spark, and air then its not cranking fast enough/low compression.


Also, the problem with your ignition switch is not unusual. Same issue happened to me. The contacts wear out inside the switch/wire causing a weak signal down to the starter. This will first show up as a click click click and then random starting, and will progressively worsen until it won't even cause the solenoid to click. Disconnect the trigger wire from the starter solenoid, have someone key on the ignition and hold it in start position, check that trigger wire and see if you have any juice coming from it at all. If you do, you may be able to add a relay down there near the starter to effectively boost the signal by using the + wire in the starter to power the relay and return a solid 12v to the trigger on the solenoid.

 

Make sure your CAM/CAS sensors are not obstructed in some way. I had a similar problem occur while on the dyno a year or so back and experienced the same sort of technical difficulties you are describing. It ended up being a loss of signal from the trigger wheel to the CAM/CAS sensors due to a film of OIL covering both sensors.

What was this causing? The injectors to not fire but everything else worked fine. Removing a spark plug yielded no sort of fuel residue at all. The pump came on, the starter engaged, the engine turned over but no fire.

Ray Wilson was the person who pointed this out (He's quite a fine tuner also)

inb4 read (I did, as well as everyone elses posts)

Just for gits and shiggles, check it out. It may even be that a wire has broken off of or come loose from one of these sensors. It may not but that's what it sounds like it could be based off your description.

Good luck!