5.0 rough idle.
Thread Starter
|
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
5.0 rough idle.
Trying to straighten out a 1992 f150 with 302 I just bought for my fiancé. I hang around the 73-79 crowd. The newer trucks are a different ball game for me.
Today I just did a tune up. Wires, plugs, cap, rotor, fuel filter. All motorcraft parts. Idle is still a little rough, you can feel it shake a little. Starts easy. Accelerates great with plenty of power. Can feel it miss a little while just cruising. Revs up good and returns to idle good. No codes showing. Should I get a code reader? I was thinking maybe problem with iac or map. Thanks for any help.
Today I just did a tune up. Wires, plugs, cap, rotor, fuel filter. All motorcraft parts. Idle is still a little rough, you can feel it shake a little. Starts easy. Accelerates great with plenty of power. Can feel it miss a little while just cruising. Revs up good and returns to idle good. No codes showing. Should I get a code reader? I was thinking maybe problem with iac or map. Thanks for any help.
Fleet Mechanic
Joined: Feb 2007
Posts: 1,252
Likes: 113
From: Mandan, ND
You can test both the IAC and the MAP using procedures in the service manual.
Two basic things to check is look over all your vacuum lines. Especially where they go from hard to soft.
Also make sure plug wires 7&8 do not run near each other. That will cause a misfire. Route them separately so they do not run parallel or touch at any point.
Start with the basics. Don't replace anything without testing it first.
Two basic things to check is look over all your vacuum lines. Especially where they go from hard to soft.
Also make sure plug wires 7&8 do not run near each other. That will cause a misfire. Route them separately so they do not run parallel or touch at any point.
Start with the basics. Don't replace anything without testing it first.
Thread Starter
|
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
Ok I'll check all the vacuum lines. I was going to make sure I routed the plug wires and separated them good with zip ties yesterday but started getting late. Ill get that done soon as possible.
Thread Starter
|
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
Checked for vac leaks didn't have any luck finding any. Also routed wires 7 & 8 away from each other. Still sounds the same, slight miss and shake at idle. Doesn't sound like it misses while being revved up and it doesn't miss under hard acceleration. Not lacking any power when you step on the throttle, it accelerates very quickly.
Thread Starter
|
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
Yes it does miss while cruising just slightly. When not going very fast and lugging up a hill is when it's most noticeable and at idle.
It does make a weird noise every time I turn it off and I'm not sure where its coming from. Every time you turn the truck off it goes "shhh" for a second like air is escaping or being released from somewhere under the good.
It does make a weird noise every time I turn it off and I'm not sure where its coming from. Every time you turn the truck off it goes "shhh" for a second like air is escaping or being released from somewhere under the good.
Logistics Pro
Joined: Mar 2005
Posts: 4,698
Likes: 47
From: Mexico, Missouri
When you say, "no codes showing. Is that just saying there isn't a CEL on or have you tried to pull codes and there weren't none? I would be inclined to try plugging/capping the vacuum line running to the EVP sensor and perhaps the EGR valve. If either is malfunctioning or worst case, both are, then it can cause a miss at idle. This age of truck could just need to clean the EGR and make sure it isn't sucking in exhaust gases at idle. If the EVP is erratic, it too can pull a slight vacuum on the EGR valve, masking the problem from itself, and the EGR not really be at fault.
Trending Topics
Thread Starter
|
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
I unplugged the EVP sensor but forgot to take off the vac line. I removed vac line from EGR and plugged it and noticed no change. I didn't actually take it off and make sure it was closed and I don't have anything to see if it will hold a vacuum. Should I actually take it off and inspect it and what to clean it with? It got dark on me fast today.
Would the PCV valve have anything to do with it? I forgot to check it. Also would the air pump not being functional cause it? I noticed the pulley on it has been removed so it won't turn. It doesn't have a converter anymore, it has true dual exhaust with flowmasters.
I haven't checked for codes but the CEL isn't on. Thanks for any help.
Would the PCV valve have anything to do with it? I forgot to check it. Also would the air pump not being functional cause it? I noticed the pulley on it has been removed so it won't turn. It doesn't have a converter anymore, it has true dual exhaust with flowmasters.
I haven't checked for codes but the CEL isn't on. Thanks for any help.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Thread Starter
|
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
What is the best way to clean egr valve? I haven't got around to it yet. Still been getting it caught up on general maintenance and cleaning.
Noticed something else. Truck doesn't hold fuel pressure in the lines very long, not even a day. Have to turn key on and let pump cycle then starts right up.
Also noticed gas leaking from the front tank. I haven't put gas in front tank since I bought it and the fuel gauge on front tank doesn't work, it just pegs out the gauge. Taping on the tank it sounds almost empty. The gas looks like it's coming from around the top.
No fuel leaks around fuel filter connections. What do I need to start looking at first? Thanks.
Noticed something else. Truck doesn't hold fuel pressure in the lines very long, not even a day. Have to turn key on and let pump cycle then starts right up.
Also noticed gas leaking from the front tank. I haven't put gas in front tank since I bought it and the fuel gauge on front tank doesn't work, it just pegs out the gauge. Taping on the tank it sounds almost empty. The gas looks like it's coming from around the top.
No fuel leaks around fuel filter connections. What do I need to start looking at first? Thanks.
Thread
Thread Starter
Forum
Replies
Last Post
jayellcowen
1983 - 2012 Ranger & B-Series
7
Jun 20, 2012 12:54 AM
mking2033
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
6
Mar 24, 2011 08:24 PM
Nathan Plemons
1987 - 1996 F150 & Larger F-Series Trucks
8
Apr 18, 2010 08:14 AM
Toyman
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
27
Nov 2, 2006 08:54 AM