258 won't start-Ignition issues???

bowtieman55

bowtieman55

Well-Known Member
Joined
Jan 25, 2006
Location
Edenton, NC
http://www.ifsja.org/forums/vb/showthread.php?t=63035
My newest FSJ, an '81 Cherokee doesn't run. It cranks over, but won't start. I'm pretty much ruling out fuel, because the fuel pump is brand new and pouring a little gas in the carb doesn't help any. I pulled the dist. cap and the rotor looks ok and is turning fine while cranking the engine. the coil is obviously good. I pulled the plug wire where it goes into the dist. cap and it is shooting fire...so the ignition module was suspect. I took the ignition module off and took it to Advance and tested it. It tested bad, so I bought a replacement (tested it before it left the store). Maybe a fuel delivery issue after all? Not hardly...hooked up a gas can to the mechanical fuel pump. The pump is definitely pumping. To be honest, I can't really see gas entering the carb, though. So I go back to think it might be and ignition problem. Again, I unplug the coil wire from the dist. cap; I can see spark when cranking. So I pull the number 1 plug wire (very front of the engine) at the spark plug. When cranking the engine, I see NO spark. Maybe it's something inside of the distributor not sending spark out? TIA
 
The only things it can be are the wires, cap or rotor, or the plugs, though not likly the plugs. It should always be the first thing you do with a new (to you) vehicle with these items to replace them. Do the tune up and if it still doesn't start but you have spark the timing is off. Good luck!
 
tknopp,

I've been thinking the exact same thing. I took the rotor button off of my '90 w/ a 360 and it still didn't start, but I could here "gargling" through the muffler. I haven't heard that all day.
 
tknopp said:
The pick up from the coil could be bad. Its rare, but i have had one go out before. You basically have to take the top half of the dist apart to get to it. its like a 20 dollar part.
Click to expand...

FWIW, the pickup looks excellent...maybe even having been replaced
258dist-3.jpg

258dist-2.jpg
 
You said you pulled the #1 plug wire at the plug and got no spark. Did you pull it at the cap too to see if its the wire?

Also, many moons ago I had something similar on my CJ. Spark wasn't getting past the distributor. I didn't find the problem till I grabbed the rotor button and realized the distributor shaft was loose. The bushing in the distributor was worn out and the shaft was wobbling.
 
I read this quickly, but if I follow,
you pulled the wire at the dizy and you see spark in the dizzy
Then pulled the wire at the plug and saw no spark?
If so, wire sounds like the culprit.

If you havent checked at the plug, stick a screwdriver in the plug end and hold it near a metal grounded piece, have someone else crank and you should see arc.

Next step, would be to pull a plug and crank agaion and see if its arcing.

If you have spark all the way into cylinder, squirt a little ether in carb while cranking, if it doesnt try to crank its timing
 
Are you sure it's not as simple as a flooded engine?

I had mine flood on me once and it stumped me for a day. then I went out and matted the throttle and cranked until it fired up. Don't rule out or over look the simple stuff.
 
I'm definitely trying not to overlook the simple stuff. It hasn't run since I've owned it and I don't know how long it hasn't ran before that.
 
The other thing it could be is a weak spark. Meaning the coil is bad. I saw it in one of those pics and looks to be original. (I think it's the rusty cyl to the left of the dist.) My buddy's '49 plymouth had a weak coil in it. It would spark and you could see it but just barely. New coil and $20 later it fired up for the first time in years! Just another option to throw at ya'.
 
yeah. I was thinking that the coil may be losing voltage while cranking. Key on, NOT CRANKING, the coil has 12.90 volts at the + terminal. I grabbed the coil off of my '90 and depending on the weather, I will try it, along with a new cap, rotor, & plugs tomorrow.
 
Do you have a haynes or chilton manual? They will tell you what the specs on your coil need to be. All you need is an ohm meter to check it. Or just go get a new one. It would be cheap insurance knowing it is new.
 
bowtieman55 said:
yeah. I was thinking that the coil may be losing voltage while cranking. Key on, NOT CRANKING, the coil has 12.90 volts at the + terminal.
Click to expand...

More importantly, what's the coil voltage DURING cranking? Depending on ignition (appears to be MC electronic from the pics?), you may not get a full 12V at the coil during cranking. If this is the case, you need to drag an additional wire off the (IIRC?) "S" terminal of the solenoid to give it 12V during cranking.

Mine would drop to about 6V during cranking and *almost* start to run as the switch went from start to run... bad $5-10 solenoid (no output on the S-terminal)

:beer:
 
Caver Dave said:
More importantly, what's the coil voltage DURING cranking? Depending on ignition (appears to be MC electronic from the pics?), you may not get a full 12V at the coil during cranking. If this is the case, you need to drag an additional wire off the (IIRC?) "S" terminal of the solenoid to give it 12V during cranking.
Mine would drop to about 6V during cranking and *almost* start to run as the switch went from start to run... bad $5-10 solenoid (no output on the S-terminal)
:beer:
Click to expand...

that's what I DIDN'T check , Dave. Yep it's got the factory Motorcraft ignition. This coil uses a horseshoe connector for the coil wiring. I hope I didn't "confuse" anybody with the way I worded it. I tested the +wire on the horseshoe connector with my DVOM. Key on, NOT CRANKING, it showed 12.90 volts. Would I test the voltage while cranking the same way? That should prove a bad coil, right?
 
new spark plugs and plug wires...no dice:shaking:
 
Maybe I'm not looking at this right, or maybe it's the angle of the pic but I'm not seeing points or a condensor.

Is this an electronic set up with a duraspark box, or does it have a pertronix kit?

If its the pertronix, I can tell you from experience, that VERY minimal gap mis-sets will prevent fire completely.

If it has the duraspark box (since you said its a motorcraft ignition)Id change it.
 
It's an '81-Duraspark electronic ignition. As mentioned, I've replaced the fender-mounted ignition module, as well as all the other bits of igniton. I'm going to do a compression check tomorrow.
 
I have a couple known good distributors if those would help. I'd be glad to let you try em out allong with a known good coil and ignition box. Got it all laying on a shelf in the shed. depending how far away edenton is come get em!:popcorn:
 
OH wow yer way out thar on tha coast! you are still welcome to come get em!!!lol:beer:
But if you are not getting spark the compression wont have any thing to do with that. So your going farther away from your problem.
 
We pulled the #2 plug, re-attached the plug wire, and rested them on the cylinder head. We DEFINITELY have fire going to/coming out of the plugs. It's not a spark issue anymore. I know the fuel pump is pumping, but looking into the carb, I do not see fuel spray.
I can see that the base of the carb is wet with fuel. Looks like I'll be pulling the carb tomorrow for a rebuild. I'm gonna do a compression test tomorrow before I go any further.
 
Do yourself a huge favor and throw thecarter carb away and put on a motocraft 2100 with the 1.08 body. easy, cheap rebuild and alot more performance on the trail. you could probably ebay one for $25 to $40
 
I'm eyeballing a 2100 right now, actually:beer:

THANKS!
 
I don't wanna sound too corny, but how close to "legal" is the 2100 swap?
 
It all depends on how closely an inspector looks at it. I'm not sure if an '81 had all the crappy Jeep smog wires/vacuum motors/solenoids/ and all the other happy jazz. I don't know what they do in non-smog counties as for older than '95 vehicles. In counties where smog checks are in effect, just a visual is needed by the inspector to make sure nothing has been tampered with. If your jeep is equipped with all the crappy (and I can't express that term enough) smog equipment, just try to hide the wires and vacuum lines that would normally go to the carter. Also, on a different note, if you're running the duraspark ICM, the voltage at the coil should NOT be 12. In the original wiring harness there should be a resistor wire to cut the voltage to the + side of the to around 6-7 volts. The old canister style coils can prematurely fail seeing full voltage. It seems as yours has survived so far, but it's something to think about. Aslo (X 2), if you're looking at a 2100 you're obviously wanting some cheap upgrades. Have you looked at upgrading the ignition system as well? An HEI/TFI upgrade is cheap and easy and you'll net a much hotter spark.
 
One of those distributors I was refering to the other day is set up with the ford cap and rotor and would be a great upgrade with a good high voltage coil. also you can get a dist from an older chevy HEI 250 6 cylinder and change the drive gear with one they sell to convert it to the 258 and have the hei set up!
 
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