Hello, new member to the forum with a 2001 Dodge Dakota 3.9l V6 w/Automatic; 111,936 miles.

To shorten the story... The ECM went out around 2 months ago, had it replaced (4 times), replaced the crankshaft sensor, plugs, wires, cap and rotor; today pulled the injectors and cleaned them out.
Problem: When truck is ran under load (uphill, kicking down to pass, etc) engine will clatter (which I believe is the fuel injectors or relay) causing the truck to jerk and causing misfires. Have tested any relay related -no problem; believe it may be electrical, but not sure.
Only parts that have NOT been replaced... camshaft sensor, O2 sensors (all 4), MAP sensor (any others?).
Now going on 3 months of aggravation, frustration, you name it!

Anyone with some ideas??

Thanks in advance for any help.

 

How exactly did you manually clean your injectors?

 

First time around, poured in an additive to the gas tank; Recently, removed all injectors, soaked in carburetor cleaner (I know! sounds bad -but got it from a web page on how to rebuild them) for about 20 min, then sprayed them off with electrical parts cleaner and air blew them out.
Re-installed them, but it seemed to make no difference. I also removed the throttle body and cleaned it out with TB cleaner.
One individual suggested I clean out the MAP sensor as it would also cause issues.

Ideas?

 

Is it throwing any codes?

 

Not currently, was throwing (before the cleaning) the flashing check engine light, meaning a cylinder misfire; but I believe that was caused by the relay/injector malfunction.
Contacted the computer rebuilder and they stated to check the battery/relay voltages and to also clean up all ground wires -have not done that yet, but by this weekend.
Strange part is that a couple of weeks ago it was running terrible, filled the tank with gas, dumped the additive then drove it around 10 miles, it stopped running bad and was purring right along !

 

Someone would have to see the live data to really be able to help you. How is your cat converter? You could have a piece of the catalyst broken off and rolling back into your tailipipe opening restricting it.

 

Converters you mean -there are two of them (hence the reason for 4 - O2 sensors), then piped into one muffler. Don't have anything yet, but don't know for sure without getting under the truck.

 

UPDATE:

Symptom thought may be an issue; when fuel is low, truck runs even worse.
Sunday; dropped fuel tank, cleaned out, checked out pump and filter -found no issues. Pulled the grounds, cleaned off for good conductivity, reinstalled. Tested battery; standing 12.83 volts, idling 14.21 volts.

Further thoughts -as the problem seems to be occurring during a load, thought I would move the distributor a touch (even though the computer is supposed to electronically modify the advance).

Any more input from anybody??

 

I've the same problem. 99 3.9l manual. The trouble only starts once the truck is put under a load usually. I've noticed that it'll start in 4th around 2000rpm then lose power, buck and jerk. If I downshift the trouble will follow to the lower gears as well. I think it must be something with the air/ fuel mixture or injectors.

I replaced my IAC, cleaned out the TB,checked for vacuum leaks or clogs,fuel additive/cleaner, changed plugs and wires and checked for loose ground wires and relays. I haven't gone through all the steps you have so thanks for the ideas.

The truck does have the Check Engine light on, I had the autozone free test done. It was calling out high voltage on O2 sensor front. But other than that I've no codes.

It's bizarre that it only starts in 4th. I can drive around town all day with no problems at all. Good luck. I'll post any findings

 

New update:

On Saturday I replaced a faulty O2 sensor, air blew out the MAP sensor and took the crankshaft sensor back to NAPA to see if they would replace it. We advised NAPA that it was having timing issues and they swapped it at no charge.
Due to the fact that it would misfire under a load (advance the timing), everything was pointing to control of the timing.

So far (knock on wood) it has worked and is running normal.