Truck in limp mode

1999 DODGE DAKOTA
165,000 MILES • 5.2L • V8 • 4WD • AUTOMATIC
Avatar
JOHN FEELEY
  • MEMBER
  • 6 POSTS
The truck is in limp mode for some reason and turns but will not fire. I replaced fuel pump,the pickup coil and the ignition coil. None of these things have worked and relays are all good.
Feb 16, 2018 at 11:24 PM
Advertisement
Avatar
ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
Good evening.

Does the engine not start?

you need fuel, spark and compression to run.

have you checked for spark and fuel pressure?

Roy
Feb 17, 2018 at 9:10 AM
Avatar
JOHN FEELEY
  • MEMBER
  • 6 POSTS
It turns but will not fire. No spark or fuel though it is a new fuel pump.
Feb 17, 2018 at 11:37 AM
Avatar
ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
Okay, I sent two diagrams for you to view. check the fuses in each diagram for power on both sides with the key on.

Roy
Images (Click to enlarge)
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Feb 17, 2018 at 8:56 PM
Avatar
JOHN FEELEY
  • MEMBER
  • 6 POSTS
Okay checked all of the fuses and relays and still in limp mode so going to try replacing the crank position sensor today and hope that works. Any other ideas would be appreciated. Thank you for your time.
Feb 19, 2018 at 2:03 AM
Avatar
ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
It is possible but a way to check is to crank the engine and see if the tach moves up while cranking. that will tell you if a signal is getting to the pcm.

Roy
Feb 19, 2018 at 4:13 AM
Avatar
JOHN FEELEY
  • MEMBER
  • 6 POSTS
Okay put in a new crank sensor and still no luck. No spark so any other ideas?
Feb 20, 2018 at 12:08 PM
Avatar
ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
Okay, can you check the voltage on the positive side of the ignition coil?

Roy
Feb 20, 2018 at 5:50 PM
Avatar
JOHN FEELEY
  • MEMBER
  • 6 POSTS
I will try that today. Thanks
Feb 20, 2018 at 8:11 PM
Avatar
ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
Keep me updated.
Feb 20, 2018 at 8:12 PM
Avatar
JOHN FEELEY
  • MEMBER
  • 6 POSTS
Took a few days break from this truck but now can say no voltage to ignition coil
Feb 23, 2018 at 12:11 PM
Avatar
ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
OK Can you test for voltage at the ASD relay with the key on?? This relay provides power to the coil and the fuel pump.

Roy
Feb 23, 2018 at 9:04 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.