I have a '75 Jeep CJ5 Renegade. It still has the original Prestolite ignition system. I am trying to make sure all of the wiring is working properly so I can install a more reliable ignition system. I want to put in the 1979 Jeep CJ7 distributor, a GM HEI module, a Ford TFI coil and etc. I have been having problems getting it started. I have done all of the basic troubleshooting tests to see if I can figure out the starting issue. I tested to see if I had battery voltage to the "S" terminal of the starter relay when the key was in the "start" position. The test showed I did have battery voltage to that terminal. However, I did not show battery voltage at the "S" terminal while in the "Run" position. I also checked to see if I had 12 volts at the Prestolite ignition module and the (+) terminal on the ignition coil. I did have good power to those two items. I did the test where you disconnect the green wire to the (-) side of the coil and I got "flashing" while the key is in the "start" position. The vehicle will start but it will not stay running for more than 3-5 seconds. I am thinking that maybe I have a problem with the key ignition switch that is located on the dash. This particular year of Jeep has a single light blue wire that comes directly from the ignition switch and is "hot" in both the "run" and "start" positions. Do you have any tips I could use to help me narrow down what the problem can be? Thanks!
Check fuel. See if the carburetor is feeding fuel.
February, 22, 2012 AT 10:55 PM
It appears I am getting fuel. I removed the top of the carb and the fuel bowl was full and the float appeared to be normal. I also disconnected the fuel line from the tank and cranked the engine. It pumped a glass jar full in just a few seconds.
February, 22, 2012 AT 11:07 PM
What happens when you rotate the throttle linkage? Can you see fuel being sprayed?
Have you checked to see if you have spark?
February, 22, 2012 AT 11:10 PM
Yes, I have spark as the vehicle will start but will not continue to run. I have not checked to see if fuel is being sprayed.
February, 23, 2012 AT 2:14 AM
Use a test light to see if the coil is constantly receiving 12 volts when the key goes from start to run. Also make sure the coil negative is being pulsed to ground.
February, 23, 2012 AT 2:20 AM
I JUST SORTA SKIMMED OVER YOUR POST
MY 1ST AND MOST IMPORTANT QUESTION I MUST ASK IS......DO YOU REALLY LOVE YOUR JEEP?
YOUR ANSWER WILL SORTA SET THE TONE FOR THIS POST!
"S" TERMINAL OR RATHER IT'S WIRE WILL HAVE NO VOLTAGE UNLESS YOU HAVE THE KEY IN THE "START POSITION"--(NOT "RUN")
THIS PUPPY WILL START--AS LONG AS YOU HAVE THE KEY IN "START POSITION"???.....THEN IT DIES WHEN YOU RELEASE THE KEY?....OR DOES IT STAGGER ON AFTER YOU RELEASE THE KEY?
PRESTOLITE IN A CJ IS SORTA JUNK!!!
I SWITCHED MINE SOON AFTER I HAD SO MANY TROUBLES WITH THE MODULE/ DISTRIBUTOR/ AND THE TEENY TINY WIRES TO IT....I TRUDGED ALONG FOR SOME TIME, BEFORE I SWITCHED IT. SWITCHING WAS REALLY EZ!
I HAVE DIAGRAMS SHOWING HOW THE WIRING GOES, AND CAN TALK YOU THRU THE DISTRIBUTOR SWAP THE EZ WAY, PROVIDED YOU HAVE NOT MOVED OR SNATCHED THE OLD ONE OUT. I CAN TALK YOU THRU THE HARD WAY TOO!
SORTA EYEBALL MY LAST CLIENT IN THIS LINK....I PRETTY MUCH HAVE ANSWERED MOST ALL OF THE CJs ON SITE, OVER THE LAST TWO YEARS
First of all, thanks for all of the replies. CJ Medevac, yes, I do love my Jeep. That is why I want to get her back on the road so I can enjoy the awesome weather we are having here in Texas. I do have the entire original prestolite ignition system in the vehicle and I do want to upgrade the ignition system to a more reliable type. In answer to your question, the jeep did start and then ran for 4-5 seconds before quitting. I guess you would call it "staggering on". When I pulled the distributor cap to see if the rotor was spinning while cranking I noticed the reluctor had quite a bit of play. As I stated in my original post I did a lot of the basic diagnostic tests using a test light and a digital multi-meter. After I got it started several times and it ran for a few seconds each time I re-checked the voltage from the starter switch to the "S" terminal on the solenoid and there was no voltage in the "Start" position. I studied the wiring schematic and traced all of the wires to ensure they were properly connected. I took the ignition module to a local auto parts store and it "passed" the test. Of course, this Jeep is one of the years and models that have things different from most of the other years. It has the key switch on the dash instead of the column. It is the first year to have a fuse panel. I looked at the fuse panel but the lettering that is on there that designates what the fuses are for is mostly gone. The fuses look good but I am going to take them out and replace them. Do you know if the lt. Blue wire that goes from the ignition switch to the "S" terminal on the solenoid passes through the fuse panel?
February, 24, 2012 AT 2:29 AM
OK, I'M A LITTLE LOST HERE
HOW ARE YOU CRANKING THE JEEP WITH THE KEY?---OR ARE YOU "JUMPING/ BYPASSING" THE SOLENOID?
IF IT'S WITH THE KEY---"S" WIRE IS FINE!!! IT IS ACTIVATING THE SOLENOID
LETS SORTA DO A LITTLE "QUICK TESTING"
DO THIS OUTSIDE---AWAY FROM GOOD STUFF---WET TOWEL AND FIRE EXTINGUISHER HANDY!!!!!!!!!!!!!!!!! USE THE TOWEL 1ST, IF THAT AIN'T CUTTIN' IT DOUSE IT WITH THE EXTINGUISHER!
YOU MOST LIKELY WILL BE FINE--NO FLAMES!
PUT A FEW OUNCES OF GAS IN AN ADJUSTABLE STREAM "SPRAY BOTTLE"...ADJUST YOUR NOZZLE IN BETWEEN A STREAM AND A MIST....REMOVE THE LID FROM YOUR BREATHER.
HAVE YOUR BUDDY CRANK HIM UP--YOU BE AT THE CARB TO SORTA "NURSE IT ALONG" (KEEP IT RUNNING) WITH THE SPRAY BOTTLE
IF YOU CAN KEEP IT RUNNING FOR ANY PERIOD OF TIME, YOU HAVE A FUEL ISSUE....COULD BE ANYTHING DOWN THE LINE...WE'LL GET TO TESTING ALL THAT, WHEN YOU GIVE THE RESULTS OF THIS....MAY JUST NEED SOME CARB ADJUSTING....I CAN TALK YOU THRU THIS/ AND OTHER TESTING/ ADJUSTING TOO
WE WILL MOVE ON INTO TESTING IGNITION COMPONENTS, IF THE FUEL THING AIN'T MAKING IT BETTER
BEFORE I DIG INTO YOUR WIRE DIAGRAM...I WANT TO KNOW HOW YOU ARE CRANKING IT?
I ALSO WANT TO KNOW YOUR ENGINE SIZE?
ARE YOU EMISSIONS TESTED IN YOUR REGION?
I WANT YOU TO LOOK FOR OPEN VACUUM LINES, OPEN VACUUM PORTS ON THE INTAKE MANIFOLD, TIGHTEN THE CARB TO THE MANIFOLD, CHECK YOUR INTAKE TO BLOCK BOLTS FOR TIGHTNESS ('SPECIALLY IF THIS IS A 6 CYL)
IF YOU WANT TO---LOOK AT THE SOLENOID EXPLANATIONS AND PICS IN THIS POST....JUST ABOVE THE PICS, THE COIL FOR "EXTERNAL RESISTOR" DOES NOT APPLY TO A PRESTOLITE SYSTEM...JUST FOR MOTORCRAFT
I APPRECIATE ALL OF THE DETAIL YOU GIVE, NORMALLY I HAVE TO DRAG STUFF OUT OF THE QUESTION ASKER. KEEP IT UP!
...IF POSSIBLE POST SOME GOOD, IN FOCUS, PICS OF BOTH SIDES OF YOUR ENGINE, MAYBE A TOP VIEW..........A NICE PIC OF THE WHOLE JEEP WOULD BE NICE TOO, JUST SO I KNOW WHAT I'M WORKING ON!
February, 24, 2012 AT 2:59 AM
Thanks for the reply. I cranked the ignition both ways. I used the key and also jumped the solenoid. It would start by both methods but would not stay running more than a few seconds. It does kind of seem like a fuel delivery issue. I will try the gas in the bottle method you suggested and have my fire extinguisher at hand. Luckily, I spent almost 36 years as a professional firefighter. The engine is a 304. When I purchased the vehicle I did notice one of the large vaccuum hoses coming from the rear of the carb plugged with a bolt. I know that can't be right as it has to have a purpose. I am not emissions tested (yet) in our region. I will take the photos of the engine compartment and other areas you requested. I have some pretty decent wiring schematics I found on various internet sites. Before I get back to you with the results of the gas in the spray bottle test I will have to wait for a friend to get off work (probably Saturday) to crank the engine over. I really do appreciate your assistance. Take care!
February, 24, 2012 AT 4:34 AM
MY CURRENT CJ 5 IS A 258
MY 1ST JEEP HAD A 304, I WAS 18, I COULD OUTRUN ANYTHING TO INCLUDE A F-16, UNTIL I RAN OUT OF 2ND GEAR (AT ABOUT 80 MPH). THIS INCLUDED A CORVETTE ONE TIME, WHEN I "HAD TO" PULL IT BACK INTO 3RD, I'D LET OFF OF THE GAS, AND SORTA WAVE 'EM OFF, AS IF THEY WEREN'T EVEN A CHALLENGE!
I DON'T KNOW IF YOU HAVE SURFED THE CJ 5 AND 7 FORUMS, HERE'S ANOTHER WITH INFO YOU MIGHT CAN USE. I HAVE ANSWERED MANY OVER THE PAST 2+ YEARS. HELPING OUT THE CJs WAS MY INITIAL CRUSADE WHEN I BEGAN ANSWERING. I MAY LINK YOU TO, OR GO BACK AND COPY AND PASTE THINGS TO YOU, AS I HUNT AND PECK RATHER SLOWLY!