Hello,
Want to share my story hoping someone can help me.
I own a 1991 dodge dakota 3,9l v6 just overhauled with bigger pistons. It worked fine for a week but did not show more power as i was hoping for and it was consuming to much more fuel after the rebuild.
After a week of using the pick up suddently shut down when i was trying to park and never turned on again it has been 4 months, it only crank but does not start.. I changed the pick up coil, ignition coil, oxygen sensor, map sensor, temperature sensor, ECM, checked the timing is ok, the fuel pump is working fine, tried everything but it does not start. Cant find the crank sensor and readed online that this pick up does not have one, And I really dont want to get rid of my pick up.
Please any advies would be very apreciate if anyone have any idea of what else i could do to make it work again. Thank you.

 

Did you change anything else to compensate for the bigger pistons? Bigger injectors, tune? Do you have spark?

 

I'd try to recall how it ran looking for signs of trouble after the rebuild. Then go over the rebuild. What did you do to the timing? You cannot set the timing on these as the ECM sets it. Using a scanner or some ridiculously complex manual method you can see the injector firing so that it fires closer to open or close of the intake valve by turning the distributor but the ECM will keep the timing in line with how it is programmed to. If it hadn't run I would say look over how you put it all back together for mistakes in alignment of the crank and timing chain and cam. The use of more gas makes sense with larger pistons. The crank Sensor is on the passenger side below the EGR bolted to the block with the sensor poking down through a hole in the bell housing.

 

OneMore94Dak - Umm, on the 91 3.9, yes, you can set timing. The LA block's ECU does some different things with its distributor (i.e., it sets spark base timing and isn't actually a cam sensor like on the Magnum V6's) so yes, we can adjust the timing. And there's no crank sensor on the LA block motors.

This changed with the MPFI setup brought in with the Magnums, natch, so for the 1992 and up, you're right. However, the LA block with throttle body injection was used through 1991 on the 3.9 (and maybe 1992, I don't remember offhand when the 3.9 went Magnum on the Dakota. Wasn't 1991, though.)

RwP

 

My bad.

 

Yes, i compensate everything i have checked the timing twice, it is good. this car does not have crank sensor. The ecm does not give the car power when i switch on the car just crank but does not receive spark and fuel, Dont know what else to do. Because everythihg is new. Please help

 

If a new ECM, but it's not getting power to the ASD while cranking, then it's time to check the wiring harness (including the ignition switch).

Then again, if the fuel pump is working, the ASD is good, so it's time to check from the ASD to the ignition coil and make sure that line is continuous.

THEN check and see if there's any spark events at the side to the ECU of the coil.

Also be sure to put a NOID light on the injectors (one at a time), so that you can verify that the injectors are firing, or not.

RwP

 

All of it have been done already but does not find the problem yet. The ECM does not give signal to the sensors. All of the wires have been check and work good