No Spark when cranking

[Lifted94XLT]

Alright guys, I finally got my motor all wired up and ready to start for the first time. I cycled the ignition and it didn't start, so first, I checked fuel pressure, and it was present, so then went to check spark at the coil.... nothing, did a resistance test and it tested fine, but replaced with a new one I had just to be sure. Still no spark. then took the TFI module off the dizzy and had it tested.... it tested good.... Then thought it may be the Ignition Pickup in the dizzy.... ended up gettin an almost new (500 miles) dizzy from a buddy, installed it, and still nothing. I'm lost.... I thought it was a ground problem, but I've got the fuel injector harness grounded to the back of the pass side head, I've got a block to firewall ground, a battery to block ground, and a block to chassis ground (grounded at the same place as the ecu ground).... the only other thing I could think of would possibly be the ignition switch? I'm kinda lost here guys. I've been messing with this for the last week now. I'm stumped. I have a feeling its something simple, but just can't figure it out. Anybody got any ideas?? Any help would be greatly appreciated.

-Ryan

 

[HISSIN50]

Did you check for a cranking signal into the TFI module?
Did you bias a test light across the coil's electrical connector to see if it flashes while cranking?
Do you have injector pulsing while cranking?

 

[Lifted94XLT]

Did you check for a cranking signal into the TFI module?

I checked to make sure theres power coming into the TFI when Cranking.... if that's what you mean, and yes, it did.

Did you bias a test light across the coil's electrical connector to see if it flashes while cranking?

Do you mean, lay a test light across the two terminals of the connector to see if it flashes?? if so, I didn't... I did check to make sure there was power goin in and coming out.

Do you have injector pulsing while cranking?

How can I check that.... with a noid light? I haven't done that yet

--Ryan

 

[liljoe07]

Test the top wire of the TFI with a test light while cranking the engine over. Its should blink. If not, then you need to remove the TFI and Ohm out the top terminal on the TFI(6 prong side), to the middle terminal one the very topside of the TFI(where there are three prongs at).

Also verify power at the positive side of the coil. And verify power at the #4 wire on the TFI with key on and cranking. And the #3 wire of the TFI while just cranking.

 

[Lifted94XLT]

Checked the top wire and it doesn't blinkl when cranking. Pulled off the tfi and showed resistance..... Check two others I have and they showed resistance too.... Not muchN but had resistance.
#3 and #4 are doing as you stated they should do. I'm stumped.

 

[liljoe07]

Looks like you need to replace the PIP sensor inside of the distributor.

Just curious, what was the resistance you got on the TFI?

edit****

I told you wrong. When doing the Ohms check at the top wire of the TFI, it needs to be done with the terminal on top of the TFI, but closest to the TFI main connector.

So you have

Top three on TFI
A B C
1 ------l
2 ----- l
3 ----- l
4 ------ } ---- TFI main connector
5-------l
6 ------l
So ohm out 1 to C, and see what you get.

Sorry about that. Either way, its the TFI or PIP sensor

If you want to check the PIP sensor. About the only way I know is to measure From points A and C on the sensor inside the distributor.

 

[HISSIN50]

Just in case the need to reference one diagram with labels is helpful:

Courtesy of S&2B's website.

 

[liljoe07]

Thanks JT......I have that some where.

Kinda throws my test for a loop though.....LOL. It has the numbers inverted. I use the top wire as #1. Where the picture has top wire at #6.

 

[HISSIN50]

I know Joe. That's why I normally don't post it (I've seen your wise TFI diagnostics in a few threads over the last week or two but there didn't seem to be any confusion so I didnt post anything).



If I made it worse, we'll just disregard the diagram. LOL. I just thought it might help ensure everyone is on the same page. You're such a smart cat and have so much of this stuff memorized that I sometimes worry that not everyone will catch where you're coming from or your point of reference.

 

[liljoe07]

I was just ribbing ya JT. Some times a visual is just for the better.

 

[Lifted94XLT]

The TFI is reading 82.3 (I hope I have it set to the right resistance setting ) That sound right?

I'm almost positive that the PIP is good. I've got a new dizzy and have two more sitting around and I have changed them all out with no change in symptoms.

--Ryan

and hissin... thanks for the diagram.... i saved it for future reference.

 

[liljoe07]

I'm going off the fact that the #1 wire on the TFI is no blinking. No blink, no spark. Only other possibility is on the Ignition ground circuit. I believe it runs to PIN 16 at the ECM. Have to check that one.

What are the ohms readings on the PIP sensor from A to C?

 

[Lifted94XLT]

I'm going off the fact that the #1 wire on the TFI is no blinking. No blink, no spark. Only other possibility is on the Ignition ground circuit. I believe it runs to PIN 16 at the ECM. Have to check that one.

What are the ohms readings on the PIP sensor from A to C?

Yes, #1 in not blinking. How do I check PIN #16. I haven't checked resistance on A to C yet.... I will tomorrow and post it up though.
--Ryan

 

[liljoe07]

A to C on the PIP sensor, not TFI. Just clarifying.

You would have to ohm the bottom wire( ignition ground) on the TFI connector, to PIN 16 at the ECM. See what the resistance is.

 

[Lifted94XLT]

A to C on the PIP sensor, not TFI. Just clarifying.

You would have to ohm the bottom wire( ignition ground) on the TFI connector, to PIN 16 at the ECM. See what the resistance is.

Been busy with work and stuff and haven't had a chance to get on here. I'll have to try and check this this weekend.... I went thru about three hours of testing (both voltage and resistance) using a Ford Technician Dealer Only software and it led me nowhere.... I'll try and check the PIN 16 resistance to the Ign Ground on the TFI and see what I come up with.

 

[liljoe07]

Don't forget A to C test on the PIP sensor.