No spark

Tiny
MARK0105
  • MEMBER
  • 1994 JEEP GRAND CHEROKEE
  • 4.0L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 225,000 MILES
Not receiving spark from coil. Fuel pressure is good. Replaced crank position sensor, distributor cap, rotor and cam position sensor. Replaced coil, spark plug wires. Still no spark. Battery is good. Neutral safety switch is good. Distributor rotor button Is spinning when being cranked over. Stumped. Any suggestions?
Do you
have the same problem?
Yes
No
Monday, February 8th, 2016 AT 3:39 AM

10 Replies

Tiny
MARK0105
  • MEMBER
Also forgot to add that I replaced computer.
Was this
answer
helpful?
Yes
No
-1
Monday, February 8th, 2016 AT 4:26 AM
Tiny
WRENCHTECH
  • EXPERT
See if you have injector pulse using a noid light. If you don't, see if you have power at one side of the injectors when the key is firsr turned on.
Was this
answer
helpful?
Yes
No
Monday, February 8th, 2016 AT 5:49 AM
Tiny
MARK0105
  • MEMBER
I'll have to get my hands in a mood light to check. I am having fuel though. I replaced the pump 6mo ago. I hear it running when I turn the key. Also when I pulled a plug out it was damp. What will the noid test lead me to? Are you thinking ignition switch?
Was this
answer
helpful?
Yes
No
Monday, February 8th, 2016 AT 4:47 PM
Tiny
WRENCHTECH
  • EXPERT
It will tell me if the power supply is going out and if the computer is receiving a reference signal. Noid lights are cheap, under $10. Just get the right one that plugs into your injector plug.

https://www.2carpros.com/images/external/1Noidlightpair__.jpg

Was this
answer
helpful?
Yes
No
Monday, February 8th, 2016 AT 4:51 PM
Tiny
MARK0105
  • MEMBER
Isn't the power supplied through the coil once the signal from the crankshaft sensor power and computer ground pulse? Which other power supply are you thinking?
Was this
answer
helpful?
Yes
No
Monday, February 8th, 2016 AT 4:56 PM
Tiny
WRENCHTECH
  • EXPERT
Please just do the testing. I can't tell you anything without some information.
Was this
answer
helpful?
Yes
No
Monday, February 8th, 2016 AT 4:59 PM
Tiny
MARK0105
  • MEMBER
I will try it out tomorrow after work. I'll pick up the noid light tester on the way home and see what happens. I'm actually interested in what the results will be. I'll keep you posted. Thanks again.
Was this
answer
helpful?
Yes
No
Monday, February 8th, 2016 AT 5:03 PM
Tiny
WRENCHTECH
  • EXPERT
While you're testing, use a test light to see if you have 12v going to both one side of the injector and the + side of the coil. This may only be there for a couple seconds when the key is first turned on.
Was this
answer
helpful?
Yes
No
Monday, February 8th, 2016 AT 5:17 PM
Tiny
MARK0105
  • MEMBER
Finally had an opportunity to check injectors. Checked three injectors using Noid light and it was blinking while cranking. I checked power at coil and had power. I bought another coil just to see if I was given a bad coil, no luck. Still not getting spark out of the coil. Getting frustrated. I heard somewhere the alarm could be an issue? I don't have a key fob so not real sure.
Was this
answer
helpful?
Yes
No
Tuesday, February 16th, 2016 AT 3:59 PM
Tiny
WRENCHTECH
  • EXPERT
Are you saying that you didn't have 12v at the + side of the coil when the key is first turned on or when cranking?
Was this
answer
helpful?
Yes
No
-1
Tuesday, February 16th, 2016 AT 4:59 PM

Please login or register to post a reply.

Recommended Guides