Rough idle and white smoke

[skiingislife725]

I've got a 1990 7.3L F350 with a rough idle problem. At first, when I'd come to a stop, the truck would start to rumble and white smoke would come out. But it would only happen some of the time. If I wait long enough it seems to just randomly start a rough idle. Now when I try to start the truck in the morning, it takes two tries before it'll start. But the rest of the day, it starts right up. Also, there seems to be a rpm surge if I get it up to 75mph at any length of time...under that is ok and over about 25mph there will be no smoke. Any ideas? Thanks.

[brett_kartracer]

It almost sounds like your timing advance lever (or it mechanism) might be sticking. It is a short lever on the right side of the pump (looking at it from the front of the engine). It moves in on the bottom when you step on the throttle and actually retards the timing when at an idle (causing white smoke and a rough idle).
There are actually many things it could be (the other guys here will be able to tell you the possiblities better than I). But check that lever and see if that is the problem.
A little more information would help though. Please fill in your signature with your pickups info (gearing, tranny, mods, etc.) Also, what color is the smoke that you are seeing? Has the pickup sat for a while? Have you changed the fuel filter and air filter lately?

[skiingislife725]

The truck is a 1990 F350 CC, 4.10 gears, E40D tranny, with a Banks Sidewinder Turbo. The color of the smoke is white. I changed out the fuel filter a few weeks ago. But when I was looking in the manual...I saw that the fast idle solenoid touchs the throttle cable linkage. But mine doesn't touch it...is there supposed to be a spring inside the solenoid that brings it up that's missing?

[cdnsarguy]

Check my gallery pics, the fast idle solenoid is operated when power is applied. So when you turn the key on and press your foot on the fuel pedal it will fill then gap and retain it until the engine reaches 112*F then it falls away when power is cut by the engine temp switch..

[CaverDave]

Can you run by the proper sequence to make it engage? I've noticed a few times, that upon cranking, it will idle normally and possibly after a tap of the pedal, the idle speed is increased... but I found nothing that led me to making it engage all the time.

[Mr_Roboto]

Check the timing retard arm on the drivers' side of the IP. It is probably sticking like mine was. Symptoms were hard starting, rough, romping idle, and tons of white smoke that never went away at idle and low speeds.

The bottom of the arm should be away from the IP at idle, and start moving towards it at half throttle and above.

If this sticks, timing is severely retarded at idle and low speeds. As RPM comes up, timing gets closer to where it should be.

[jslash]

[ QUOTE ]
Check the timing retard arm on the drivers' side of the IP. It is probably sticking like mine was. Symptoms were hard starting, rough, romping idle, and tons of white smoke that never went away at idle and low speeds.

The bottom of the arm should be away from the IP at idle, and start moving towards it at half throttle and above.

If this sticks, timing is severely retarded at idle and low speeds. As RPM comes up, timing gets closer to where it should be.

[/ QUOTE ]

Mr_Roboto!!!

BINGO!! I've been told for the past year that my IP is shot and I
need a new one. But wasn't *sure* and didn't want to spend the $'s
until I could diagnose the problem accurately. Well, your description
gave me the needed info to diagonse... I started the truck this
weekend... Blowing lots of white smoke... moved the timing retard
arm *out* and she smoothed out, RPM's when up a tad and NO WHITE
SMOKE!!! Thanks soooo much!... BUT, it will stick again as soon
as I stomp on the throttle [img]/ubbthreads/images/graemlins/wink.gif[/img] Sooooo... Is this something that
can be replaced or should I just replace the pump. It has 135k on
it and I'm sure other things could be ready to fail soon. For $370
it might not be worth messing with.

Opinions??

Thanks again Mr_Roboto!!!!

Jim/

[Fred Hemer]

If you want to try and baby it along you can try some of this
http://www.dieselpage.com/add3.htm It may help ya thru but sooner or later yer gona have to do the pump!
If you use this stuff you need to dump the whole bottle into the tanks on the first go if the problem clears up then continue to use as a regular doseage as directed!

[d9d]

Roboto is da man, no doubt [img]/ubbthreads/images/graemlins/biggrin.gif[/img]

You said the -lever- is sticking ? If that's the case, it's an -external- problem; and you may be able to fix it yourself for nothing. That lever rotates on a little axle. Make it turn freely and you're good to go.

But that lever pushes in a pin on the side of the IP, and if the -pin- is what's sticking in.... Then you gotta try Fred's hair-tonic, or get a rebuilt IP.

The way you described it, it sounded like the -lever- was the issue though.

BTW, a rebuilt IP shouldn't cost you more than 300. I just got one for 299 from MWFI; and someone recently posted that Tim at accuratediesel.com sold him a rebuilt IP for $215.

[jslash]

[ QUOTE ]
BTW, a rebuilt IP shouldn't cost you more than 300. I just got one for 299 from MWFI; and someone recently posted that Tim at accuratediesel.com sold him a rebuilt IP for $215.

[/ QUOTE ]

http://www.mwfi.com/dieselPage/ford_73.htm

This is true for an '88-'91. But the '92-'94's (my Turbo in particular)
are $366.72. So I think I'll be ordering one of those units soon.

Thanks again for the help guys!

Jim/

[skiingislife725]

Sorry I haven't posted in a while...I checked out the lever on the driver's side of the IP and it seems to be working fine. Do I need to remove the IP to get to this pin that the lever pushes in and out? Can I just mark the IP with a line or a circle and take it off? Or do I need to be able to dynamic time it and whatnot? Thanks.