blue smoke at easy cruise

[stresscrack]

my 93 f350 7.3 no turbo w/ bio diesel, starts, runs and pulls great but when i let up on the throttle to maintain speed it puffs blue smoke. when its cold no noticeable smoke but after its worked you can smell the over fuel at idle and the tailgaters are blinded by my blue smoke. there is no check engine light and no oil consumption. where should i start ?

[Mat J]

get your injectors checked, or atleast when you pull them out after sitting see if they are wet, sure sign of a leaker. but get the pop off pressure tested to check them or just replace them if they are painted grey or have alot of miles on them.

[Dave Sponaugle]

stresscrack,
Welcome to FTE and the IDI diesel forum.

Have you serviced the CDR?

[stresscrack]

nope i have not cleaned the cdr. been reading threads trying to figure out why and how. thanks for the welcome. this info u guys give is awsome

[Mat J]

just wash it out with gas till its clean, dont used compressed air. its the tuna can behind the air cleaner.

[stresscrack]

by the way truck has 128k miles on it. also it up shifts ok but it wont down shift when u mash the gas it just chugs along but the smoke goes away

[Dave Sponaugle]

A 93 should have an E4OD, the FILP on the injection pump sends the downshift signal to the tranny.

It also requires the tach and speedo work correctly.

[stresscrack]

is the smoke at cruising altitude and the no down shifting both related to the filp ? is the filp the same as a throttle position sensor ? thanks for all the help

[Dave Sponaugle]

Throttle position sensor (TPS) and fuel injection lever position sensor (FILP) are the same thing.