hello i am new to this forum and i just put a new re-manufactured jasper motor in my truck replaced all the intake sensors injectors and complete distributor wires plugs exc,exc .so basically all new even replaced the PCM ECM ECU computer . it has a Ruff idle and the long range fuel trim is like -33 by the way i replaced the cadillac converter and both O2 sensors

took it to local shop jot the injectors synchronized but still runs ruff at idle . Ok , but not perfect going down the road better then the motor i replaced with 200K plus miles on it

any suggestions

 

Check the crank sensor, they tend to take a beating if not installed AFTER the motor is in there.

Getting any codes?

Which engine??

 

it is a 5.9L I had a random misfire code on 3 and 6 cylinder but narrowed it down to the #3 elc tro in the cap was set back to the outer edge so put another new cap on I just drove it the fuel trim evens out but still don't idle or not throwing a coad yet

 

Misfire codes stay gone? How did you plenum look when you had it off? (did you swap motors, or a shop?)

 

Coad came back on when fired it up to bring in shoo po300 po300 po300 I swap the motors I was a mechanic a 100 years ago before they sewed everything up with electric sensors

 

Still random misfires then. Have an Oscilloscope? I would be tempted to see what your spark looks like on one.... It would definitely let ya know if ignition was your trouble....

 

I'll have to do that ...it's crazy ran great earlyer with no coad the started it to pull it in the shop and bam
thanks for the help with this

 

Did you double check the firing order to ensure that you have the plug wires routed correctly? Also, check to ensure that all of the wires are firmly connected at the distributor cap and at each plug.

 

i changed the crank sensor, so now all is new
now i'm getting a inconsistent reading off my pick-up coil should be at 5 volts its all over from "0" to overload what would cause that ?

 

On which wire? supply, signal, or ground?