Run on?
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Joined: Mar 2001
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Run on?
Does anyone else have a problem with engine run-on after the engine has completely warmed up? My truck will run on for a few seconds unless I drag the clutch to stop it. Just curious, as my dad has said its been doing this since new. thanks for help/suggestions!
-Chris
1980 F-250 4x2 LB
NP-435 non OD w/ 3.55 rear end
soon to have new clutch and new rims w/ LT255/85R16 tires
I'll have traction again!!!!
200K and going... and going..
-Chris
1980 F-250 4x2 LB
NP-435 non OD w/ 3.55 rear end
soon to have new clutch and new rims w/ LT255/85R16 tires
I'll have traction again!!!!
200K and going... and going..
Senior User
Joined: Sep 2000
Posts: 385
Likes: 0
From: Flat Rock, Michigan
Run on?
Do you mean that your engine keeps running a couple seconds after you turn it off?
if so:
Check your engine idle...sounds like she's idleling too fast. Spray down your carb linkage with some Gumout carb spray...if its dirty it will hang-up and your idle won't go down all the way.
If you need to adjust your "warm idle" ....the "idle screw" is the closest screw to the carb in the rear of carb. Don't get it mixed up with the high speed choke idle screw (closer to the firewall).
1981 F-150 2WD STYLESIDE P/U
4.9L 1 BBL CARB
C6 AUTO
2.73:1 LIMITED SLIP REAR AXLE
STABILIZER BARS FRONT & REAR
6100 LB GVWR PACKAGE
ORIGINAL OWNER
193,000 PLUS MILES
100% STOCK & UNREBUILT
BUILT FORD TOUGH!!!
if so:
Check your engine idle...sounds like she's idleling too fast. Spray down your carb linkage with some Gumout carb spray...if its dirty it will hang-up and your idle won't go down all the way.
If you need to adjust your "warm idle" ....the "idle screw" is the closest screw to the carb in the rear of carb. Don't get it mixed up with the high speed choke idle screw (closer to the firewall).
1981 F-150 2WD STYLESIDE P/U
4.9L 1 BBL CARB
C6 AUTO
2.73:1 LIMITED SLIP REAR AXLE
STABILIZER BARS FRONT & REAR
6100 LB GVWR PACKAGE
ORIGINAL OWNER
193,000 PLUS MILES
100% STOCK & UNREBUILT
BUILT FORD TOUGH!!!
Senior User
Joined: Feb 2001
Posts: 119
Likes: 0
From: Dryden Canada
Run on?
If the timing is out you could experience run-on as well ... or a combination of bad timing and fast idle. I have this problem with the 351W in my Torino when the timing gets out. I good old fashioned tune-up should help some.
Senior User
Joined: Feb 2001
Posts: 119
Likes: 0
From: Dryden Canada
Run on?
Possible causes of dieseling (run-on) are:
1. Idle speed is too high ... engine may not have warmed enough for it to 'kick down' or the idle speed isn't adjusted right.
2. Fuel or electrical system problems. These could take a while to find and should be looked at if other easier ideas don't help.
3. Ignition timing incorrectly adjusted ... set it or take it for a tune up.
4. Thermo-controlled air cleaner heat valve not operating properly. I'm guessing this could lead to the choke not opening and the idle not 'kicking down' properly.
5. Excessive engine operating temperature ... although I'm thinking you would KNOW if your engine was overheating when the dieseling is occuring.
A couple of these were already mentioned, but some of the others are options of those don't work out. Always try the easiest thing first!
Chris in Canada
74 Gran Torino Brougham ... anybody want one?
84 F150 2WD 300I6/NP435/3.08 rear
1. Idle speed is too high ... engine may not have warmed enough for it to 'kick down' or the idle speed isn't adjusted right.
2. Fuel or electrical system problems. These could take a while to find and should be looked at if other easier ideas don't help.
3. Ignition timing incorrectly adjusted ... set it or take it for a tune up.
4. Thermo-controlled air cleaner heat valve not operating properly. I'm guessing this could lead to the choke not opening and the idle not 'kicking down' properly.
5. Excessive engine operating temperature ... although I'm thinking you would KNOW if your engine was overheating when the dieseling is occuring.
A couple of these were already mentioned, but some of the others are options of those don't work out. Always try the easiest thing first!
Chris in Canada
74 Gran Torino Brougham ... anybody want one?
84 F150 2WD 300I6/NP435/3.08 rear
Freshman User
Joined: Jan 2001
Posts: 30
Likes: 0
Run on?
When I use regular or mid-grade gas, I get dieseling with my '78. 92 or higher octane, and the problem goes away.
I suppose using the high grade gas could simply be masking a poor adjustment, since I don't have any pinging problems with lower octane. Just the run-on. Though the run-on has persisted across carbs--both the stock 1bbl and a 500 Edelbrock.
I suppose using the high grade gas could simply be masking a poor adjustment, since I don't have any pinging problems with lower octane. Just the run-on. Though the run-on has persisted across carbs--both the stock 1bbl and a 500 Edelbrock.
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Freshman User
Joined: Oct 2000
Posts: 34
Likes: 0
Run on?
Chris,
I had this problem with mine too. I was getting a code 13 sometimes which meant the idle speed was incorrect. I looked up this problem on the Mitchel Repair Info CD and the library and it gave a procedure to set the curb idle (anti-diesal) screw correctly. That is the one referred to in the replies above (closest to the carb). If you mess with this one to increase your curb idle speed, you are probably increasing it too much. My emissions sticker has a procedure to do check it but it doesn't really say how to adjust it correctly if it is off. Basically, this other procedure has you do some things to retract the idle speed control motor so the throttle is resting on the anti-diesal screw. If idle is not 500 RPM plus or minus, you make it so young Skywalker. I don't know how to post a scanned image of the procedure or even if it is possible so if you email me at rpspwp@home.com, I'll reply to you with it (and anyone else that want's it). Good luck.
Will
'84 F150
YFA F/B
SROD
"Ex" => Bone Stock
I had this problem with mine too. I was getting a code 13 sometimes which meant the idle speed was incorrect. I looked up this problem on the Mitchel Repair Info CD and the library and it gave a procedure to set the curb idle (anti-diesal) screw correctly. That is the one referred to in the replies above (closest to the carb). If you mess with this one to increase your curb idle speed, you are probably increasing it too much. My emissions sticker has a procedure to do check it but it doesn't really say how to adjust it correctly if it is off. Basically, this other procedure has you do some things to retract the idle speed control motor so the throttle is resting on the anti-diesal screw. If idle is not 500 RPM plus or minus, you make it so young Skywalker. I don't know how to post a scanned image of the procedure or even if it is possible so if you email me at rpspwp@home.com, I'll reply to you with it (and anyone else that want's it). Good luck.
Will
'84 F150
YFA F/B
SROD
"Ex" => Bone Stock
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