IDI Surge
Thread Starter
|
Senior User
Joined: May 2013
Posts: 286
Likes: 0
From: Salem, OR
IDI Surge
In the last couple days my 86 6.9 N/A has started to surge at about 40/50 mph. It seems to have a flat spot like its running out of fuel, then after a few seconds it will surge fwd (as much as an IDI will surge). It seems to be getting worse lately. I have no visible fuel leaks, so am assuming it could be any place between the tank and injectors.
All suggestions are appreciated.
Also does anyone have experience w/a Donaldson 4" x 40" lg muffler #M085421? I'm going to replace the stock exhaust taking it out the back. I am not sure what would be the best muffled to keep it reasonably quiet yet reduce back pressure. I've read some about diesel drone, don't know if that's a turbo issue or effects all diesels, but I want to be able to carry on a conversation in the truck.
Thanks
All suggestions are appreciated.
Also does anyone have experience w/a Donaldson 4" x 40" lg muffler #M085421? I'm going to replace the stock exhaust taking it out the back. I am not sure what would be the best muffled to keep it reasonably quiet yet reduce back pressure. I've read some about diesel drone, don't know if that's a turbo issue or effects all diesels, but I want to be able to carry on a conversation in the truck.
Thanks
Senior User
Joined: Jul 2010
Posts: 170
Likes: 0
From: Western SD
Changed the tach sensor and everything went away.
Postmaster
Joined: Dec 2004
Posts: 2,941
Likes: 30
From: Maple Valley, WA
Sounds like an advance piston issue in the pump...
Early on in the DB4 stuff, the bigger cam pin caused light load advance issues like your saying, and it was due to the change in dimension of the trim piston... It would pulsate at around 50-60mph...
If you have no fuel system leaks, Id look at your IP for a worn advance piston assy...
Early on in the DB4 stuff, the bigger cam pin caused light load advance issues like your saying, and it was due to the change in dimension of the trim piston... It would pulsate at around 50-60mph...
If you have no fuel system leaks, Id look at your IP for a worn advance piston assy...
Freshman User
Joined: Jul 2013
Posts: 25
Likes: 0
my truck does the same thing when it gets just below half a tank on either the front or the rear. 90 350 7.3
Trending Topics
Logistics Pro
Joined: Sep 2007
Posts: 3,737
Likes: 179
From: Western Mass
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
New User
Joined: Jun 2007
Posts: 2
Likes: 0
From: Orangevale
My'93 F350 does the same thing right at a quarter tank on the front tank and now the rear tank. When I first got the truck I dropped the tank and it was a cracked pick up disc on the sending unit. Added a small piece of fuel line and now goes till its almost empty. Didn't get the right part because when I called around the parts places told me their was a few different styles used by Ford. Didn't have to drop tank completely, just got it tipped and could weasel the sender out. Going to do it right someday.
Thread
Thread Starter
Forum
Replies
Last Post
Leftyizme
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
2
Mar 15, 2015 04:32 PM
boots6868
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
15
May 25, 2011 10:23 PM