No Spark or Fuel During Engine Crank

[Lumpy Grits]

IF-you have a 'crankshaft position sensor'(CPS). I would be check'n to see if it's working. When they fail, the entire system shuts down.
There is no neutral safety switch(thank God)on any OEM Jeep manual tranny.

LG

 

[Posi]

Can't speak for the 80s, but all late 70s CJs came from the factory with a neutral switch, in both autos and manual Transmission . The manuals came with a metal strap to override the neutral switch.

 

[Lumpy Grits]

Posi-In all of the CJ's I've worked on. Have never seen a NSS on any CJ manual.
I can assure you that my my '85 CJ7 that I bought new, didn't have one either.
Can you show me this metal strap you speak of? I just can't picture it.
THX,
LG

 

[hagar]

Can't speak for the 80s, but all late 70s CJs came from the factory with a neutral switch, in both autos and manual trans. The manuals came with a metal strap to override the neutral switch.

Not on any manual transmissions in CJ models.

 

[Posi]

Check out a 1979 factory CJ wiring schematic
My 79 with manual vin code F has one with the metal strap.

 

[Posi]

Not sure if this will work, trying to post one page.

http://oljeep.com/gw/79_tsm/79_Jeep_TSM.pdf

OK, that's the complete manual, if you go to wiring it will be the first diagram on the left side of the page.

The manual override metal strap will be above the neutral switch "For manual Transmission "

 

[Lumpy Grits]

Check out a 1979 factory CJ wiring schematic
My 79 with manual vin code F has one with the metal strap.

CJ5 or 7?........
I have worked on a couple '7s' from that year with OEM manual trannys and there was no operational NSS.
What's in the harness is a 'catch-all' for all versions. My 7 has the wiring in the loom for a NSS with an auto. My OEM T-5 , has no provision for a NSS. Just a 2-pin back up light switch.
LG

 

[Posi]

5 or 7 doesn't matter, they made one harness and simply installed the metal strap on the manual Transmission .
I believe they did away with them in manuals in the 80s

 

[Lumpy Grits]

WOW-that was a well detailed FSM!
Section 2J-37 states that the NSS was only used with an auto.
I can't get it to 'paste' here for some reason.......
LG

 

[Posi]

Can't speak for the 80s, but all late 70s CJs came from the factory with a neutral switch, in both autos and manual trans. The manuals came with a metal strap to override the neutral switch.

My first post, so we're on the same page.

 

[Posi]

WOW-that was a well detailed FSM!
Section 2J-37 states that the NSS was only used with an auto.
I can't get it to 'paste' here for some reason.......
LG

That's because the metal strap overrides the switch.
Look at my previous post.

 

[thundley57]

IF-you have a 'crankshaft position sensor'(CPS). I would be check'n to see if it's working. When they fail, the entire system shuts down.
There is no neutral safety switch(thank God)on any OEM Jeep manual tranny.

LG

No CPS but thanks!

 

[thundley57]

If you have 5.5v at the + coil with key on your resistor wire is fine, no need to check that. You first said it had 0v that's why I ask you to check the terminal from the + side coil to dash connector.

You already ruled out the light blue wire, and starter solenoid. I believe you will find your problem in the red ignition wire running from the ignition side of the starter solenoid to where it splices into the red ignition wire running to the + coil. Sometimes that splice gets crusty. Make sure all your connections at the starter solenoid, and coil are clean as well.

I already ran a jumper from the positive side of the battery to the ignition side of the starter and still no start. Doesn't this rule out the red ignition wire?

 

[007]

That's because the metal strap overrides the switch.
Look at my previous post.

Page 1F-3 shows the strap...

For those of you with earlier / late 70's (like a 76-78) it's on page 3-30 of your TSM.

 

[Posi]

Thanks 007, the learning curve on posting stuff like that is way too high for me. =)

To add, on a no start problem the strap is one of the things I test. I never stumbled on a broken strap, but have found some rusted causing a voltage drop.

 

[007]

Thanks 007, the learning curve on posting stuff like that is way too high for me. =)

To add, on a no start problem the strap is one of the things I test. I never stumbled on a broken strap, but have found some rusted causing a voltage drop.

Ha! No problem... I made the post on the website, then took a picture of the PDF section, then edited my post in Tapatalk to add the picture.

There is NO better way to post pictures than with the Tapatalk app on a phone. The whole process took less than 1 minute.

 

[Lumpy Grits]

:ty: Both for the education here.
That shows NSS was only used in the auto. IIRC, the 3 speed was the T-150 which had no NSS provision.

LG

 

[Posi]

What that picture shows is a metal strap bypassing a neutral switch on a manual Transmission , be it T-150 or T-18 .

 

[Posi]

I already ran a jumper from the positive side of the battery to the ignition side of the starter and still no start. Doesn't this rule out the red ignition wire?

Do you mean starter solenoid or starter?

If you mean starter solenoid then no it wouldn't rule out the red ignition wire. You have battery voltage at the ignition side but you have a voltage drop of 3+v from there to the coil. Chase the red wire to the splice and see what's going on there.

Do you have a stock coil and distributor?

 

[thundley57]

Do you mean starter solenoid or starter?

If you mean starter solenoid then no it wouldn't rule out the red ignition wire. You have battery voltage at the ignition side but you have a voltage drop of 3+v from there to the coil. Chase the red wire to the splice and see what's going on there.

Do you have a stock coil and distributor?

Sorry Posi, I meant starter solenoid. I do have a stock distributor with the Team Rush upgraded taller ford cap and a high energy e-core coil.

Here's an update to my problem after quite a bit of more troubleshooting this evening:


Engine won't start, no spark from coil. The Howell furnished ECM is working normally as indicated by the check engine light coming on in the run position and staying on while cranking. The electric fuel pump kicks on for a few seconds when the key is in the run position but then does not come on while cranking (as it should) probably because it isn't receiving a tach signal.

* I do have 12V to the ignition side of the starter solenoid while cranking (I think I had my digital volt meter on the wrong range when I previously reported lower voltage, sorry for the confusion).

* I have about 1V less than this (11V) at the positive side of the coil while cranking.

* I have 12V to the red wire going to the Duralast ICM and 12V while cranking to the blue wire that goes to the module (white on the module side).

* I installed my brand new spare Duralast ignition module (no change).

* I installed my brand new spare e-core coil (no change). Both coils tested about the same with my ohm meter with about 2 ohms on the primary and 8000 ohms on the secondary

* A few weeks before the failure I installed a new coil pickup in the distributor. Is it possible this part may have failed or would I still get spark out of the coil even if it has failed?

The only other thing I can think of is the green wire from the ignition module to the negative side of the coil. I tested the resistance between the coil and the icm and there was not an open and was about 1 or 2 ohms. Does anybody know what voltage I should be getting at negative side of the coil while cranking?

Please guys, I'm at a loss and have been spending several hours each evening trying to figure this out. My last resort is to tow her to a shop and let some guy I've never met before have a crack at her! I'm a serious DIY guy (great at some things, not so great at others) and can't bring myself to do this!