Shutting off and Backfiring?

CAT HORTON

MEMBER
1998 DODGE DAKOTA
3.9L
V6
4WD
MANUAL
190,000 MILES

Hello, I have been helping my friend try to fix his truck and nothing has been helping so far. We have changed the Cap, Rotor, IAC, Oxygen Sensors, CPS, MAP, Ignition, Coil, Coil Wire, and probably a few more sensors. We have checked all of the wiring. Reset the CPM. Have had three of the best shops here look at it. But it still is not working properly. It runs great for a few days after a new part is put in and then it starts doing it all over again.
I have been on almost every site on the subject, but even the older posts do not have an actual fix mentioned. Is there even a usual problem with a standard fix? Or is it so varied that it is a mixture of issues that need to be addressed?
This morning it went about two and a half blocks Backfired extremely loud and died. It took a few tries to get it restarted and then died two more times on the way back home. Please tell me that there is a simple fix to this. It is really frustrating and very expensive.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,418 POSTS

Hi,

The idea that it backfires is usually either a fuel-related issue or a timing issue. Have you tried to retrieve diagnostic trouble codes? If so, were any found?

Take a look through this link and let me know if it is at all helpful:

https://www.2carpros.com/articles/engine-backfires-while-running

Next, is there any timing chain noise that you notice? They are known to get sloppy which can vary timing when it's running. One other question. Does it backfire from the throttle body or is it from the tailpipe?

If it is the tailpipe, have you checked the fuel pressure and the pressure regulator? If not, do that next.

Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know as much as you can. Additionally, when it does backfire, does it then continue to run properly?

Take care,

Joe