Hi. Haven't wrote in the forum for a long time. Recently my diesel truck (81) starting running pretty rough. I took it to my local mechanic and he said it was motor mounts. I knew they were bad, so we replaced all except one by timing belt. Also noticed a leaking fuel line at injector. Replaced that and it still was running rough. We then noticed it was the injector leaking. So I ordered a new injector and replaced it.
The truck is still running rough. Smooths out when driving but real rough at idle, slight vibration on steering wheel, etc.
My question is if one injector went bad should the other 3 be replaced, or could it be in the pump. What are the signs a pump is going bad. Thanks in advance.
Unlikely to be the pump, all injectors should be serviced as one.
Any air in the lines when running?
Often engines are a bit lumpy at idle because the idle has dropped, lifting the idle on the residual fuel setting will give a better idle - is there a rod on the back of the pump that links the cold start linkage to the idle control lever - if so turn the slot on top of the rod clockwise a few turns until the idle settles.
If not, adjust the minimum throttle stop a turn or so to lift the idle speed.
My truck wouldn't start and i had to replace the fuel filter.
Thanks, I'll check it out tomorrow and adjust it. Will order more injectors and install them. I thought that should have been down. Thanks for the reply. Appreciate it.
I checked out the rod on back of pump. Found the linkage and slotted screw. There is no adjustment left. Won't turn clockwise even a little???? I'll adjust the throttle stop a little and see if that helps. Thx
If you have a rod, you shouldn't pick the idle up on the throttle stop if possible.
the top linkage is slotted so you can regain more adjustment on the rod, but you should normally need to move this unless it's slipped.
You could turn the fuel up a 1/8th - 1/4 turn, you'll get more power as a result. adjuster next to the fuel solenoid, locked of with a 13mm nut against the pump body. There should be a metal collar preventing any tampering here but it may have been removed previously or if not, you can normally adjust it a little anyway.
Thanks for the info. I've made an appointment with a knowledgeable caddy mechanic. Take it in next week. Thanks for your input.