'89 with a dead spot
Thread Starter
|
New User
Joined: Jan 2011
Posts: 16
Likes: 0
'89 with a dead spot
Been wracking my brain on this one.
'89, 302, 5 speed truck has a dead spot where it won't wind past 2500-2600 rpm. Rail pressure is 32# at idle, 40# all in. Tested the ICM, it's good.
Been that way for a little while now. When I first got the truck, I could fly up a mile long 7% grade in 5th doing 65 and still have enough throttle to pull harder. Now, I'm lucky to make it up the same grade at 35mph, because the flat spot is forcing me to short shift to keep it under the dead spot.
Have a feeling I'm overlooking something obvious, just can't put my finger on it.
'89, 302, 5 speed truck has a dead spot where it won't wind past 2500-2600 rpm. Rail pressure is 32# at idle, 40# all in. Tested the ICM, it's good.
Been that way for a little while now. When I first got the truck, I could fly up a mile long 7% grade in 5th doing 65 and still have enough throttle to pull harder. Now, I'm lucky to make it up the same grade at 35mph, because the flat spot is forcing me to short shift to keep it under the dead spot.
Have a feeling I'm overlooking something obvious, just can't put my finger on it.
Thread Starter
|
New User
Joined: Jan 2011
Posts: 16
Likes: 0
Plugs, wires, and cap are all less than 30k miles old. No misfire, just a dead spot, and no ignition break up. Gonna check the timing tomorrow. My old man has my timing light. He's coming over to help me with some house remodeling.
New User
Joined: Nov 2015
Posts: 21
Likes: 0
If fuel good would be my guess but how can you one see the fuel pressure up a grade?I have an 89 same exact setup tank 2 causes alittle of an issue on grades but getting better thinking the DFR but it also causes a problem Sometimes when taking off in 1st gear under a load much like the hill then clears up when the pressure is on.
Trending Topics
Fleet Mechanic
Joined: Nov 2011
Posts: 1,823
Likes: 43
From: New York
Pull your PCM, open it up, and check for leaking capacitors. If it's still the original computer, it's a good bet the capacitors are leaking and that can cause unpredictable behavior.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
Get a fuel pressure gauge with a long enough hose so you can tape it to the windshield to view while driving. I've done it for years.
Thread
Thread Starter
Forum
Replies
Last Post
SteelCitySeth
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
12
Oct 25, 2017 02:40 PM
Pilgrim
1987 - 1996 F150 & Larger F-Series Trucks
5
Dec 28, 2005 08:25 AM
bugser
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
5
Oct 11, 2005 12:29 AM