• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Short story

D

DVM04

NAXJA Forum User
Location
Northern, NJ
So I am driving to work today in my 92 xj and enjoying the 75 degree whether when the truck dies. Just coasting to a stop on a nice busy road and wait for AAA. Have fuel, can hear the pump and smell it. Suspect no spark and will start playing with it after work. CPK sensor is only 3 months old, but that is where I am starting.......

And to think she is for sale to.....

Thats all just had to vent....
 
So replaced the CPK sensor and no spark, got plenty of fuel. So I moved to the coil. Have 12 volts to the coil in run and crank. When I test the output of the coil(plugged in), I have nothing leaving the coil to the disty. Is there anything else that controls spark from the coil to the disty? If 12 is going in an dnothing coming out, leaves me to think the coil is kaput....
 
There is a camshaft position sensor in the distributor. If the CRANKshaft position sensor isn't the culprit, the CAMshaft position sensor is another likely suspect.
 
Answers like you got from Eagle is one of the main reason's I support this forum. Post up and let us know what you find.
 
Dumb idea, but can you make sure that it's not +12VDC @ 100% Duty Cycle? If the coil is "always hot," it won't fire.

Coil discharge depends upon voltage being interrupted at the primary - the magnetic field collapsing due to interruption of primary voltage induces the voltage in the secondary, which gives you the spark.

If nothing else, I'd probably hook up a low-power light bulb, and see if it flashes, rather than being lit all the time.

That would allow you to narrow it down between the coil primary or secondary failing, or if the "switch" (ignition control module or circuit in the SBEC) has gone kaput on you.

5-90
 
I tested the coil last night, got the 1.4 ohms across +/- which I think is ok. I replaced the disty, coil, and CPK all in the last 3 months, I know that doesnt mean that one can die but just concerning. I still think the CPK is the culprit. I swapped out the one inthe truck with a spare which used to work. The coil and CPK are under warranty from Autozone so I am going to swtich them out and see what we can find. I will move onto the CPS if I strike out, that only has about 1k miles on it when I replaced the disty.

I love this truck but find the electrical gremlins so frustrating. IF its not spark issues I have fuel pump power issues. Its always something. I know every car has its faults. Thanks for listening.
 
ASD relay? I'm not sure if your year has one....but it kind of sounds like you are not sure if you have fuel or spark. Rent or borrow(or buy) a fuel pressure gauge if you don't have one. That will tell you for sure on the fuel pressure. As far as the spark goes, just have an unsuspecting buddy grab a plug wire and......no, maybe that's not a good idea. But you know what I mean. Check your spark, find out for sure.:)
 
DO not have spark, definetly have fuel and abut 40lbs of it. I have dealt with more fuel issues in this truck and replaced the entire electrical fuel circuit trying to find the problem (previous posts). This is spark related so need to track it down, will replace the CPK and coil, will keep you posted.
 
DVM04 said:
DO not have spark, definetly have fuel and abut 40lbs of it. I have dealt with more fuel issues in this truck and replaced the entire electrical fuel circuit trying to find the problem (previous posts). This is spark related so need to track it down, will replace the CPK and coil, will keep you posted.
Click to expand...

10-4 keep us posted.
 
DVM04 said:
I tested the coil last night, got the 1.4 ohms across +/- which I think is ok. I replaced the disty, coil, and CPK all in the last 3 months, I know that doesnt mean that one can die but just concerning. I still think the CPK is the culprit. I swapped out the one inthe truck with a spare which used to work. The coil and CPK are under warranty from Autozone so I am going to swtich them out and see what we can find. I will move onto the CPS if I strike out, that only has about 1k miles on it when I replaced the disty.

I love this truck but find the electrical gremlins so frustrating. IF its not spark issues I have fuel pump power issues. Its always something. I know every car has its faults. Thanks for listening.
Click to expand...

Erm, you'll note that I didn't say to check the resistance of the coil primary - I wanted you to check voltage going INTO the coil primary, and see if it was anything other than constant.

Constant voltage will NOT cause the coil to "fire," and indicates a problem upstream somewhere. Since you'd replaced most of the parts recently, that seemed like a logical next step, and what I'd do.

5-90
 
Sorry I misunderstood what you said. So I replaced the CPK sensor and left the coil alone, tried to start the truck and no spark. So I started testing power at the coil. In run I had 12 volts with the +/- side of the volt meter in the two connections plugging into the coil.Turn the key to crank it and would drop to zero. Plugged the coil in and turn the key to run, had 6.5 volts, crank it and drop to zero. Did this twice and same thing. Moved back one last time with the + of volt meter on coil output to disty and negative on battery ground. I started notices that during cranking that the volt meter was actually flashing inside (glowing), plugged the coil wire into the disty, turned the key and it ran, have shut it down and started it three times, starts everytime.......So was the cpk bad and needed time to reset? Or is there something that is not closing this coil all the time? I am not convinced this is fixed.....
 
First off you are going to need a new volt meter. The limit on input voltage on most is 400-1000v. The coil wire will generate 40,000+. The glowing you saw was arcing inside the meter.
 
Guess what same thing, no spark this morning, even with the new CPK sensor from last week. Nothing at the coil again. Like I thought last week unlikly another CPK sensor is bad. The coil and cpk have less than 1k miles on them as does most of the engine electronics. The problem is before the coil/ Anyone have any suggestions?
 
A bad cam position sensor on a 92 should send out a code. Any codes?

When the cam position sensor on my stepson's 93 went bad, it would not start, but when I turned on the ignition, and then unplugged the distributor connector, I heard various sensors resetting, and it then started. It would not restart again without the same procedure, but it ran fine once started. Worth a try, and if it works it is a definitive diagnosis of a bad cam pos. sensor.
 
Did you unplug the cam positioning sensor during cranking? I just bought a low-power light bulb and there is nothing at the coil that is sending off the light bulb. There is steady 12 volts to the coil but not flashing of the light so I think this is a ground issue. I just replaced the Crank positing sensor last week adn the disty is only 1k miles old. I disconnected everything at the alternator and cleaned all the contacts, checked for good continuity from the coil connector to the alt and its good. So I think this is something like 5-90 suggested:

"That would allow you to narrow it down between the coil primary or secondary failing, or if the "switch" (ignition control module or circuit in the SBEC) has gone kaput on you."

Thanks again and no codes, nothing at all
 
Replaced the Crank positioning sensor with the old one, still nothign no spark from/to coil. What interupts the 12 v at the coil to spark?
 
Code 54 is a bad camshaft position sensor (in the distributor). Although this controls injector timing, not spark, the computer will not boot up to start if it is bad. But it may run. Try unplugging and then replugging with ignition on - not while cranking, just with ignition on. May not work for all cam sensor failures but it did for mine.
 
Last edited:
You must log in or register to reply here.

Similar threads

DustyWagoneer
Few More XJ Parts (Wrightwood)
Replies
0
Views
217
DustyWagoneer
DustyWagoneer
G
No Start After Welding, Fuel Gauge Not Working. I'm seriously confused.
Replies
9
Views
2K
tjmotter
tjmotter
C
97 XJ I am at my wits end
Replies
5
Views
3K
GravyDavey
G
Saudade
Speedo Deado
Replies
4
Views
2K
Anak
Anak
J
1991 Cranks, Fires, then dies.
Replies
15
Views
2K
Runnin'OnEmpty
R
Back
Top