Cranks but doesn't fire

[str8stang036]

I am starting the stang up after months of reconstruction. The car cranks however doesn't even make an effort to fire. I did remove the distributor to install an new intake. So possibly it may be off.

I also checked for voltage at the ignition coil and there is no voltage. Not sure why. I l then checked the TFI module and its getting voltage. Cap and rotor are fine, TPS is at .98v. What else do I need to check that I am missing? This very similar situation already happen to me the first time I fired it up about 1 year ago.


Jose

 

[KamiKaziDK]

pull the dizzy and crank the engine over by hand till the #1 piston is tdc and reinstall it, probably just 180 out

 

[urban96]

pull the dizzy and crank the engine over by hand till the #1 piston is tdc and reinstall it, probably just 180 out

+1

 

[HISSIN50]

Did you check for spark?

The coil gets constant accessory 12 volts. The ground to it is modulated.

If you dont have power to the coil, check interior fuse 18. You might have pinched a wire or otherwise shorted the circuit. Check all other fuses while at it.

 

[str8stang036]

The fuse 18 was ok, and all the other fuses in the engine box are ok also.

I have not checked for spark yet, I will do that tomorrow. Also, if the coil gets constant I should be able to get voltage from it, correct? I checked it, and I didn't get any voltage.

Weird thing is that I didn't touch any of the wiring after the reconstruction. I will put the dizzy at TDC tomorrow

 

[HISSIN50]

The red/lt grn (positive coil) wire should indeed show constant 12 volts with your DMM. You will have to use another source for the ground [e.g., the battery's negative terminal] since the - coil terminal isn't a constant ground.

If you have that, check for spark. If no spark, put a test light across the two electrical terminals going to the coil (one of which you just tested for accessory 12 volts at) and see if the test light flashes while cranking. If it does, the coil is bad.

If the test light doesnt flash, go back to the TFI and test that same wire (tan/yellow IIRC) for pulsed ground while cranking. If you have it at the TFI but not at the coil, the wiring between is bad. And if you dont have it at the TFI, that's another batch of testing.

 

[str8stang036]

I am going to check it tomorrow because today the battery crapped out and I need another one.

What is the quickest way to find TDC?

 

[KamiKaziDK]

Pull plug one, stick a feeler in there and crank the engine by hand

 

[str8stang036]

The weirdest thing happened today. I had left the battery charging over night and when I went to crank the engine it blew up! What would cause something like this? I know the battery was bad, but I have never seen one blow up

 

[hotrodredneck]

have it hooked up wrong?

 

[HISSIN50]

Did the charger have circuitry to trickle or float once charged? You can get an explosion on a discharged battery through the outgassing. I suppose the same thing could happen on an overcharged battery.

Was it a big explosion or more of a boom/thud? Did it mess anything up?

 

[str8stang036]

Oh, yea it was a big boom, it made my ears ring for a few minutes. nothing was messed up because it is in the trunk.

The charger doesn't let me know when its done charger, it just has 10amp and 2 amp setting. I put it on 2amp all night. Well I will get a new one and hopefully it doesn't blow.

 

[HISSIN50]

I've had batteries pop before but not explode! I'm glad you're ok.

If the car acts up, check all the fuses. The battery might have shorted internally, which could take out some fuses, fusible links, etc.

 

[str8stang036]

Just did a few tests. I put a test light across the coil terminals and it did not flash. I then checked the TFI module and it gets power. I tested the PIP signal from stator to the module with a test light and it did not flash as I cranked the motor.

I did hear clicking when I was back probing the module for the PIP signal, it seemed to be coming from the connector of the distributor to the fuel injector harness. I disconnected it and it no longer clicked.

According to the haynes manual it says to replace the stator if I have power but no flashing when cranking, is this accurate? The same thing happened last time but last time it turned out to be that I had connected the distributor to the 02 harness since they looked the same. Once I figured that out, it fired up.

My Distributor is practically brand new, MSD Pro Billet 8451.

 

[str8stang036]

It just started! Turns out the positive primary coil wire was broken in one of the crimps I made. Fixed that and it started right up. Thanks to everyone for their input.

 

[99FiveOh]

Maybe your problem is with the MSD. I haven't actually owned one myself, but I see thread after thread about them malfunctioning, sometimes right out of the package. Swap in your stocker or see if you can get your hands on a known good one and try that.

These cars are wired pretty good from the factory, so usually it's something simple that causes these problems... that is, as long as nobody hacked up the harnesses!

edit: congrats on finding the problem!