Truck won't Start

[dinghyboy]

1992 4.0l Auto 4WD

 

Went to start the truck. It cranked for 1/2 a second then nothing. no lights, no radio, no buzzers, nothing at all. Disconnected the battery and cleaned terminals and now have all electrics working. Truck will crank over but will not fire. I had disconnected the battery for some other work and had just placed the positive cable back on without tightening the clamp.

 

Disconnected the fuel lines at the fuel rail. When I turn the key to ignition, i get a pulse of gas, then when I crank the motor, it has fuel flow.

 

Pulled plug wire number one and cranked the engine and there s NO spark at no.1 cylinder. Reconnected Plug 1 and tried same test on cylinder 6, same result, no spark.

 

I have tested all the fuses in the engine compartment fuse block and have continuity across all the fuses, none are blown. I switched the starter relay and the fuel pump relays in the fuse box and same results.

 

Where do I look next. IS there an ignition fuse somewhere I'm missing?

 

Just for full disclosure, I had just replaced the valve cover gasket and the truck started after that. Then I installed a wiring harness with relays and 2 Halogen headlamps. The lights worked after installation with no apparent problems. Was starting the truck to pull out of the garage when the problems started.

 

Appreciate all insight.

 

Gavin

[HOrnbrod]

Check for spark at your ignition coil output HV wire. If none, check for 12V at the ignition coil connector (key ON). Also make sure you didn't inadvertently unplug the distributor connector.

[comanche1989]

Check conditions of battery cables. A short in the battery cable could possibly cause this.

[Geonovast]

Also make sure you didn't inadvertently unplug the distributor connector.

 

 Or the CPS connector.

 

 

Isn't the CmPS for injector control?  I thought it had nothing to do with spark.

[ftpiercecracker1]

My money is on CPS, but do what Hornbrod said first.

[dinghyboy]

Check for spark at your ignition coil output HV wire. If none, check for 12V at the ignition coil connector (key ON). Also make sure you didn't inadvertently unplug the distributor connector.

 

Thank you all for your help. I'm thrilled to say she's running again and embarrassed to say I probably screwed it up to begin with. 

 

I had spark at the coil and had about 9 volts at the input on the distributor connector. The CPS tested just fine with a resistance test. .  So what did I screw up?

 

I had the valve cover off and it's quite possible that while I was scraping off the oil sludge from the valve train, I may have put my weight on the distibutor cap. One of the terminals was broken loose and the rotor button was broken into three pieces. The result was that when I cranked the engine the rotor wasn't spinning. Put on a new rotor button and distibutor cap and she'd good to go. Just as a precaution, I did wiggle the distributor shaft but it seemed tight.

 

Thanks again for your input. I learned something from your help.

 

Gavin