Q: Its backfiring mostly while driving, loss of power, fuel consumption, motor doesnt idle smooth, P0300 code, no timing codes

asked by on

All of a sudden my motor runs like crap. I bought this motor used with around 80,000 miles on it. Just started backfiring out of the driver side exhaust (dual exhaust). Does it at idle and a lot when put in Drive gear. I did an oil change, spark plugs, spark plug wires, tried to set timing but its off 20-30 degrees after setting it right. No matter how I set the distributer its always +20 or more degrees. Like first setting in the distributer its at +20 and plug in the cam position sensor on the back of the distributer it goes to +30 degrees. I'm in Colorado so it should be at least 7 degrees. If its running this way and timing is way off no matter what, what are all the cases it could be? Was told timing chain and/or injectors.

My car has 160920 miles.
My car has an automatic transmission.

Hello. The symptoms you are experiencing can be caused by a wide variety of issues. If the ignition timing is significantly advanced, this is likely part of the reason for your misfires and performance issues. A few things I would check are the ignition module, crank position sensor, and cam position sensor. These all play a role in ignition timing and can cause issues if they are having any problems. It may also be possible that the issues are mechanical, perhaps due to a problem with the timing chain or distributor. If either of these components jump a tooth somehow, perhaps due to wear, they can cause the timing to advance or retard a significant amount. It may be possible that there is a need to look at the fuel injectors, however in most cases the fuel injectors do not affect ignition timing. If you are unsure, I would recommend having a professional technician, such as one from YourMechanic, come to your location to diagnose the cause of your misfires and performance issues.

Was this answer helpful?

Hi there. The timing chain being at fault is remote, had a similar experience with timing fixed (out of specification) regardless of distributor position. No timing codes. The upper distributor shaft bushing was excessively worn and replacing the distributor assembly took care of the timing issue. Once the timing issue is resolved. The backfiring, loss of power, and excessive fuel consumption could be the result of a leaking fuel injector(s) on bank (1). I recommend having your vehicle’s Check Engine Light On be diagnosed and repaired by a certified technician, such as one from YourMechanic.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Its backfiring mostly while driving, loss of power, fuel consumption, motor doesnt idle smooth, P0300 code, no timing codes

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Rattling sound/bells from under the vehicle heard 2016 ram1500 5.7L 15000 miles only heard between 20-40mph 2000rpm accelerating

Hi there. Typically when you have a rattling noise as you've described, it's caused by a loose bracket or other component that might have been removed to complete the oil change for some reason. I wouldn't suspect that the rattle...

Q: I have an issue with my Tahoe its idling rough the hand stays on 500 rpms but you can hear it in the engine

It would appear you have already attempted to perform all of the normal repairs to fix this issue. Due to the high number of repairs made, you may want to start by retracing your steps and confirming that all the...

Q: Truck is hard starting and when it does start it shut off when you put it in gear

You need to have the fuel pressure checked to see if the fuel pressure regulator is leaking fuel into the intake which is flooding the engine out. If the fuel regulator is proven to be bad then replace it. Afterwards,...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...