idle problem
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idle problem
2000 ranger 2.5 stick, coming to a stop i put in the cluch and the motor speeds up then slows down sometimes more sometimes less.
A month ago I had a code PO171, with a good idle. I cleaned the MAF senser then cleared the code, a week later the the CIL came back on same code. Then a month after the CIL is on the engine idle problem started. So I recleaned the MAF with MAF cleaner, cleared the code, and replaced the ICV with a new one. That worked good for about 3 days now the idle problem is back again.
The idle problem seam to be worse when the motor is warm or has been running at freeway speeds. Any new ideas??
A month ago I had a code PO171, with a good idle. I cleaned the MAF senser then cleared the code, a week later the the CIL came back on same code. Then a month after the CIL is on the engine idle problem started. So I recleaned the MAF with MAF cleaner, cleared the code, and replaced the ICV with a new one. That worked good for about 3 days now the idle problem is back again.
The idle problem seam to be worse when the motor is warm or has been running at freeway speeds. Any new ideas??
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From: SW Va
P0171 = System adaptave fuel too lean. A number of things can cause this, as the system has been trying to compensate for a problem & its reached its adaptive limits & can no longer compensate for whatever is wrong.
So things like a vacuum leak, clogged fuel filter, weak fuel pump/low fuel pressure/low delivery rate, old/slow switching up stream O2 sensor, worn out, dirty/sticking open PCV valve, dirty MAF sensor, well you get the idea. We need some more clues, like where are you on on all past & present due scheduled replacement maintenance items, like fuel & air filters, O2 sensor & PCV valve replacement?
Have you done any diagnostic testing, like looked/tested for vacuum leaks, done a fuel pressure test, looked at long & short term fuel trim, monitored the O2 sensors switching speed & range with a scantool???
Have you posted All trouble code Numbers, as they can give good trouble shooting clues.
So things like a vacuum leak, clogged fuel filter, weak fuel pump/low fuel pressure/low delivery rate, old/slow switching up stream O2 sensor, worn out, dirty/sticking open PCV valve, dirty MAF sensor, well you get the idea. We need some more clues, like where are you on on all past & present due scheduled replacement maintenance items, like fuel & air filters, O2 sensor & PCV valve replacement?
Have you done any diagnostic testing, like looked/tested for vacuum leaks, done a fuel pressure test, looked at long & short term fuel trim, monitored the O2 sensors switching speed & range with a scantool???
Have you posted All trouble code Numbers, as they can give good trouble shooting clues.
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cleaned maf, new icv, new air filter, new hose from valve cover to intake, cant find any vacume leaks.
Have not replaced fuel filter, pcv, o2 sensers, have not test fuel presure,
Also after one day of no CIL (i cleared it) today the CIL came back on with one code po171 again.
next i will replace pcv value and do a subsituted swap from my other car of the MAF sencer
For what its worth . . . . when I come to a stop and put in the cluch the engin will speed up then as the car roll to a stop the enine will idle down always.
Have not replaced fuel filter, pcv, o2 sensers, have not test fuel presure,
Also after one day of no CIL (i cleared it) today the CIL came back on with one code po171 again.
next i will replace pcv value and do a subsituted swap from my other car of the MAF sencer
For what its worth . . . . when I come to a stop and put in the cluch the engin will speed up then as the car roll to a stop the enine will idle down always.
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From: SW Va
Take the time to do some diagnostic testing, before throwing parts at the problem. Like break out your scantool & have a look at short & long term fuel trim, MAF & O2 sensor PID's to the computer, so see if what they're telling the computer is within range & have a look at fuel pressure with your fuel pressure gauge.
If you don't have or can't borrow a scantool or fuel pressure gauge, break out your vacuum gauge & do some testing to have a look see at what it suggests. https://www.ford-trucks.com/forums/8...-tutorial.html
If you don't have or can't borrow a scantool or fuel pressure gauge, break out your vacuum gauge & do some testing to have a look see at what it suggests. https://www.ford-trucks.com/forums/8...-tutorial.html
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From: SW Va
I have the same scantool & it'll do that & more, so your well equipped for a trouble shoot. Let us know what you find.
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Got more info. At idle, mph 0
abslt tps 20.4
rpm 980
calc load 33.3
maf lb/m .33?
coolant 192
Iat f 115
ign adv 27.5
lt ftrm1 25
st ftrm 1 7 -12.5
speed 0
fuel sys 1 clsd?
fuel sys 2 n/a
02511 (v) .120-.755
st ftrm 11 7-11
02512 (v) .045
abslt tps 20.4
rpm 980
calc load 33.3
maf lb/m .33?
coolant 192
Iat f 115
ign adv 27.5
lt ftrm1 25
st ftrm 1 7 -12.5
speed 0
fuel sys 1 clsd?
fuel sys 2 n/a
02511 (v) .120-.755
st ftrm 11 7-11
02512 (v) .045
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From: SW Va
We know you said the above data was taken at idle & the data says it was at closed loop & the coolant temp reading says it was at a warm operating condition, BUT I'm not clear how the engine was loaded??? So, was it in "P" or "N", AC, blower motor & headlights Off???? In other words was the engine under no load????
The RPM is a little high, so did you grab the numbers shortly after a start, before the engine idled down & stabilized????
Not sure about the TPS value yet.
On the fuel trim numbers, is the - (dash) a misplaced figure between the numbers, or does it indicate negative numbers???? Fuel trim typically switches between +/- 5 to 8. So, right now, depending on if you have +, or - numbers, it looks to be slightly lean or rich. So we need clarification on the fuel trim numbers sign.
On the O2 sensor switching range, it looks ok, But was it rapidly switching, or was it slow/lazy????
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I was on the freeway and pulled off the off ramp and parked. I think the ac was on. I used the dash to say the number was moving up and down. Im not sure what was with the higher idle, earlier it was idling at 720. Im going to go back and do a recheck today. Also its a stick shift so i was parked, out of gear, with the cluck out.
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Test 2 engine warm, parked, out of gear, all electcial off, ac off, parking brake on, CIL on.
ABSLT TPS 18.0
RPM slow move up/dn 820~850
CALC LOAD slow move up/dn 22.7~24.7
MAF LB slow move up/down .32~.38
COOL 192
IAT 115
IG ADV slow move up/dn 9~12.5
LT FTRM 24.2
ST FTRM fast move up/dn -.08~6.3 (dash is a minus)
SPEED 0
FUEL SYS 1 CLSD
FUEL SYS2 N/A
O2S11 (V) fast move up/dn .135~.780
ST FTRM11 fast move up/dn .8~10.9
O2S12 (V) .035
ABSLT TPS 18.0
RPM slow move up/dn 820~850
CALC LOAD slow move up/dn 22.7~24.7
MAF LB slow move up/down .32~.38
COOL 192
IAT 115
IG ADV slow move up/dn 9~12.5
LT FTRM 24.2
ST FTRM fast move up/dn -.08~6.3 (dash is a minus)
SPEED 0
FUEL SYS 1 CLSD
FUEL SYS2 N/A
O2S11 (V) fast move up/dn .135~.780
ST FTRM11 fast move up/dn .8~10.9
O2S12 (V) .035
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From: SW Va
Test 2 engine warm, parked, out of gear, all electcial off, ac off, parking brake on, CIL on.
ABSLT TPS 18.0
RPM slow move up/dn 820~850
CALC LOAD slow move up/dn 22.7~24.7
MAF LB slow move up/down .32~.38
COOL 192
IAT 115
IG ADV slow move up/dn 9~12.5
LT FTRM 24.2
ST FTRM fast move up/dn -.08~6.3 (dash is a minus)
SPEED 0
FUEL SYS 1 CLSD
FUEL SYS2 N/A
O2S11 (V) fast move up/dn .135~.780
ST FTRM11 fast move up/dn .8~10.9
O2S12 (V) .035
ABSLT TPS 18.0
RPM slow move up/dn 820~850
CALC LOAD slow move up/dn 22.7~24.7
MAF LB slow move up/down .32~.38
COOL 192
IAT 115
IG ADV slow move up/dn 9~12.5
LT FTRM 24.2
ST FTRM fast move up/dn -.08~6.3 (dash is a minus)
SPEED 0
FUEL SYS 1 CLSD
FUEL SYS2 N/A
O2S11 (V) fast move up/dn .135~.780
ST FTRM11 fast move up/dn .8~10.9
O2S12 (V) .035
So, a vacuum leak, like hose condition (soft/mushy, hard & dryrot cracked, loose fit) belong on your suspect list, as do an intake gasket leak, dirty fuel injectors, low fuel pressure from clogged fuel filter, weak fuel pump, kinked fuel line, sticking open PCV valve, cracked/leaking PCV valve hose or loose connection, are some things that come to mind.
Yah I know, it would be easier if something were just plain bad & stand out, but right now all the clues you have is the adaptive limit code & + fuel trim numbers that suggests the computer is correcting for a lean condition.
Let us know what you find.
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still not working. I check all hoses, removed and inspected pcv valve which is good, recleaned MAF, check fuel presure which is a 68, replaced the up stream 02 oxygen senser (between the cat and engine) reset the CIL which is not back on yet. after i installed the new 02 the engine ran good for about one hour and now its back to increased rpm when i put in the cluch coast to a stop then it idles back down . . . so the idle is relivent to the speed of the vehicle (clutch in out of gear) 5 out of 10 stops it will idle down normally. two days ago i replaced the ICV, air filter.
Right after i installed the new 02, warmed the motor then rescaned with the following:
tps 17.6
rpm 800~833
load 22.7
Iat 81
Ign adv 12.0
lt ftrm 25
st ftrm 6~9
sp 0
02411 .1~.7
st ftrm11 6~9
02512 .045
Right after i installed the new 02, warmed the motor then rescaned with the following:
tps 17.6
rpm 800~833
load 22.7
Iat 81
Ign adv 12.0
lt ftrm 25
st ftrm 6~9
sp 0
02411 .1~.7
st ftrm11 6~9
02512 .045
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another odd thing . . . . engine idles about 800~833 but then i disconnect the idle control valve and engine idles down to about 725 and runs perfect, 
smooth and always idles down when i come to a stop. I thought that if you unplug the ICV the motor would die.
smooth and always idles down when i come to a stop. I thought that if you unplug the ICV the motor would die.
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From: SW Va
Have you inspected the PCV valve rubber connecting plumbing, or replaced the PCV valve????