I just bought 1990 dodge Dakota 3.9 v6 and one day after I bought it the timing chain went and bent valves the works.so i replaced one of the heads the chain a valve or two and now that I put it together it runs terrible .no horsepower idled rough act s like it's running out of gas but is actually running too rich .it runs better when I disconnect one of the injectors .when I plugged in both it's chokes out on gas probly getting 4 miles or less to the gallon . Did the codes it said bad map sensor so I replaced it but still the same .no other codes I think maybe I got intake manifold leak not sure .did compression test all cylinders
were 130 or better help

 

Moved to the correct section.

 

Is the temp sensor the ECM uses plugged in?

 

After the timing chain catastrophe, did you also check ALL the valves; did you reset the ignition timing (before anyone else posts, the 1990 was an LA motor and yes, you can set ignition timing on them); did you make 100% certain the timing marks were right on the two gears?

Those are three things that catch some people.

Also, did you check the pushrods, especially for the valves that were bent? They may also be bent. Check the lifters to make sure they weren't collapsed permanently.

RwP

 

I would start and make sure everything is plugged in. Double check timing, and plug wire configuration. After all is checked, that nothing is left loose etc. I would check compression. If I understand correctly, you replaced one head, and some of the valves? Was this done by a machine shop? If not, you may have a valve not sealing, and that will show on a compression test.