idle
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Joined: Dec 2006
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From: central ohio
idle
when i start my truck up after sitting for a couple of hours it will idle like a new car. the engine doesn't shake at all. but as it warms up it gets worse. it will shake the whole truck. if i put it back into park it will idle somewhat decent, just little shaking nothing like when in drive.
i think the iac is going bad. it is a cheap p.o.s. from autozone. never have any luck with iac's from there.
the other day i was out unplugging vacuum lines and the one going into the egr valve when i unplugged it i put my finger over the line and it did not change the way it ran at all. also there is a line coming out of the canister down by the radiator with a line coming out a little sensor inline. i unplugged it and it did absolutely nothing.
could one or more of these problems be causing my bad idle?
i think the iac is going bad. it is a cheap p.o.s. from autozone. never have any luck with iac's from there.
the other day i was out unplugging vacuum lines and the one going into the egr valve when i unplugged it i put my finger over the line and it did not change the way it ran at all. also there is a line coming out of the canister down by the radiator with a line coming out a little sensor inline. i unplugged it and it did absolutely nothing.
could one or more of these problems be causing my bad idle?
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From: central ohio
i also remembered that a pink line running from the canister over around the top of the engine to around where the two air pump check valves are located on the drivers side of the motor came into contact with the egr valve and burnt into the valve and i am not sure if it closed completely or not. i know it is not leaking.
it idles like crap like i said. but as soon as i give it gas it runs great. i dont know if this means anything thing but it is an 89' 351w.
it idles like crap like i said. but as soon as i give it gas it runs great. i dont know if this means anything thing but it is an 89' 351w.
Elder User
Joined: Feb 2007
Posts: 829
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From: Goose Creek SC
IAC usually causes low idle and stalling I think. TPS is another problem sometimes.
Your's sounds more like vacuum problems after the lines get hot. Vacuum lines are known to crack right at the fitting and the heat then opens them causing a leak. The canisters(coffee can) rot out on the bottom where you can't see them too. If that pink line is vacuum.....it's probly leaking. I'd definitely spend some time in the "Vacuum line checking mode" first.
Then Check your codes.......the egr can cause bad rough running too from what I read here. And you might see codes pointing right to the problem.
Good Luck
Bob
Your's sounds more like vacuum problems after the lines get hot. Vacuum lines are known to crack right at the fitting and the heat then opens them causing a leak. The canisters(coffee can) rot out on the bottom where you can't see them too. If that pink line is vacuum.....it's probly leaking. I'd definitely spend some time in the "Vacuum line checking mode" first.
Then Check your codes.......the egr can cause bad rough running too from what I read here. And you might see codes pointing right to the problem.
Good Luck
Bob
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Joined: Jun 2006
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ALL of the plastic lines are vacuum lines. They don't collapse like rubber does.
Nothing under there will have pressure in it except the fuel line and the radiator hose. If one of those gets a hole, you know it pretty quick. If ANY of the lines cracks, it will affect performance in some way, mostly manifesting itself as a vacuum leak. Fast rough idle is the first clue there is a vacuum leak.
DOH, I almost forgot, if you're pressing the washer button, that RUBBER hose will have pressure as well.
Nothing under there will have pressure in it except the fuel line and the radiator hose. If one of those gets a hole, you know it pretty quick. If ANY of the lines cracks, it will affect performance in some way, mostly manifesting itself as a vacuum leak. Fast rough idle is the first clue there is a vacuum leak.
DOH, I almost forgot, if you're pressing the washer button, that RUBBER hose will have pressure as well.
Elder User
Joined: May 2007
Posts: 754
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From: Solon, Ohio
Nothing will happen when you disconnect the vac line to the EGR while it is ideling because the EGR is supposed to be closed during idle.
It could be stuck open partially however and could be the cause of the rough idle.
It could be stuck open partially however and could be the cause of the rough idle.
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From: central ohio
i am sorry it took so long to reply. been busy
but yesterday it started to hesitate real bad. when the motor is cold like early in the morning or going home from work. i will sit at a stop light and it will idle like it usually does, (the whole truck is shaking) and when the light turns green i will step on the gas and the rpms will drop way down, down far enough i thought it stalled. but after it warms up it has no hesitation.
as for a vacuum leak. i would say i can't find one doing a visual inspection. i also sprayed all the line with carb cleaner and the idle didn't change.
i have not gotten a check engine for a couple of months and that was when the egr position sensor went bad. i know the light works cause it comes on when i start it.
but yesterday it started to hesitate real bad. when the motor is cold like early in the morning or going home from work. i will sit at a stop light and it will idle like it usually does, (the whole truck is shaking) and when the light turns green i will step on the gas and the rpms will drop way down, down far enough i thought it stalled. but after it warms up it has no hesitation.
as for a vacuum leak. i would say i can't find one doing a visual inspection. i also sprayed all the line with carb cleaner and the idle didn't change.
i have not gotten a check engine for a couple of months and that was when the egr position sensor went bad. i know the light works cause it comes on when i start it.
Post Fiend
Joined: May 2004
Posts: 11,289
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From: Lakewood, Ohio
you could have a code with no light on.
the temp sensor that gives the ecu info could be the problem.
or the autozone iac.
the temp sensor that gives the ecu info could be the problem.
or the autozone iac.
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From: central ohio
which coolant sensor is it? the one on the intake manifold or the one on the front of the motor.
one of the replys was about the egr being stuck open, would that be causing this. the valve that is on the truck now is the original one so it is 18+ yrs old.
one of the replys was about the egr being stuck open, would that be causing this. the valve that is on the truck now is the original one so it is 18+ yrs old.
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From: central ohio
ok. those aren't very much money so that won't be hard to change.
another thing what would cause it to idle much better when in park versus when in drive? when in park it idles what i believe a 18 yr old car should idle like, not like a new one but pretty close.
another thing what would cause it to idle much better when in park versus when in drive? when in park it idles what i believe a 18 yr old car should idle like, not like a new one but pretty close.
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From: central ohio
okay well i finally got around to checking my codes today and here is what i got koeo 22, 33 and koer 21.
21 is the coolant sensor being out of wack. changed it so see how it works. good guess quicklook you are the man.
22 is map sensor being out of self test range. i think i did this the other day when i unplugged it while it was running.
33 is egr valve not opening and it says on fordfuelinjection website that this is a koer test or in cm. so can this one be right?
sorry it took so long but last weekend i was busy helping my sister move, and working on getting heat in the beast
21 is the coolant sensor being out of wack. changed it so see how it works. good guess quicklook you are the man.
22 is map sensor being out of self test range. i think i did this the other day when i unplugged it while it was running.
33 is egr valve not opening and it says on fordfuelinjection website that this is a koer test or in cm. so can this one be right?
sorry it took so long but last weekend i was busy helping my sister move, and working on getting heat in the beast
Tuned
Joined: Aug 2007
Posts: 321
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From: Tulsa, Oklahoma
I have an 88 F-250 with a 351W also and I am having idle problems similar to yours.
It runs fine when cold but when warm mine has dead miss and starts surging real bad
when at a stop light in gear. My check engine light comes on after about 15 minutes of driving.
Does yours cut out any at certain speeds or RPM ??
It runs fine when cold but when warm mine has dead miss and starts surging real bad
when at a stop light in gear. My check engine light comes on after about 15 minutes of driving.
Does yours cut out any at certain speeds or RPM ??
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From: central ohio
no i don't have any problems with surging or misses. as a matter of fact i drove mine 215+ miles last weekend and never got a single cel. i just have a shaking idle that shakes the whole truck.
i have had problems with the tps and had to change it cause mine would run fine, i would stop for a stop sign or light and it would die. try to start and nothing i would be able to get it running, but only if i gave it gas. but as soon as i let off the gas to put it in gear it would die. and then just as soon as it appeared it would leave and run fine.
i have had problems with the tps and had to change it cause mine would run fine, i would stop for a stop sign or light and it would die. try to start and nothing i would be able to get it running, but only if i gave it gas. but as soon as i let off the gas to put it in gear it would die. and then just as soon as it appeared it would leave and run fine.
