1990 D-150 runs rough
 

1990 D-150 S, 318 TBI automatic. Everything original to truck is still in place.

Last week, my Truck started missing and jerking while driving to work. I got there popped the hood, and couldn't see anything out of normal since it was dark. Before I shut the hood I seen a spark jump where the wire mounts to coil.

Thought ok, in morning I'll pull the wire and make sure its snug befor going home. Did that and it ran like a champ.

Next day same thing happened, no sparks jumping around anywhere this time, so I figured probably time for new cap and rotor.

Did all of that and runs fine until it gets warm and starts missing and jerking while driving and now a noticeable miss when warmed up.

Thought what the heck, scan tool is showing no codes other than 024 which is a cruise control servo code. Truck doesn't have cruise.

So I put a new fuel filter on it and a new coil. Runs perfect, until it gets warm and starts falling on it's face again.

I have scheduled an appointment with a local repair shop next week, but would like to figure it out myself before eating a big repair bill.

Any advice from the experts??

Thanks

Gary

Maybe a defective reluctor in the distributor the ECU might be going bad.

My skill level on those rule me out. :eek:

Thanks

I noticed today that the injector on the passenger side of the truck is making a chug chug chug sound, not the normal hessing sound that a good running throttle body makes.

I checked the spark plugs and number 2 and 6 on the passenger side were black and sooty, 4 and 8 looked normal.

Could an injector going bad cause the engine to run ruff and not set a computer code>>

Yes. The needle inside can hang open or the spring weak....

I fixed it. I checked the wires going to the sooty plugs, ohm test with my multi meter, then checked the wires going to the good plugs. I had three bad wires. I had the high dollar Taylor wires on it, less than a year old.


Purchased a new set of spark plug wires, put them on, now she is running like a top! :-)

I still have the noise on the one injector, I ordered a pair, and will replace both here in the next week.

Thanks again for all the ideas

:-)

i just replaced the injectors. Do I need to disconnect the battery so the computer will not be thinking I still have one bad injector?

No,
You might have to clear all the codes it the heck engine light is Still/Was on.

Thanks,

No codes on the scan tool, and it is running very smooth. I guess I'm good :dance:

If I remember correctly the light will go off after so many start and run cycles.:)

Hehehehehehe.... You are good... :)