Scan tool diagnostics
12-03-2011, 10:36 AM
#1
Scan tool diagnostics I've had trouble with high idle as of late. It running about 1500 at idle. using my scan tool I read that the IAC count is at 0 and the pcm is requesting idle of 750 rpm. TPS is at 0 and TPS voltage is at .5v. That tells me both the IAC and TPS are good and that I have a vaccum leak. Anyone else agree?
12-03-2011, 04:34 PM
#2
it also seems to idle up as it warms up. when it has sat for awhile, KOEO it shows a IAC count around 120. When I fire it up, it idles at 1000. The IAC count starts coming down like it trying idle it down, but it doesnt work. Then, slowly the idle comes up to 1500.
If I fire it up after its sat for a bit, it start out at 1000 rpm. If I blip the throttle, the idle then settles at 1500.
Ideas?
If I fire it up after its sat for a bit, it start out at 1000 rpm. If I blip the throttle, the idle then settles at 1500.
Ideas?
12-03-2011, 08:10 PM
#3
wrencher
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Throttle body sticky? (up 500 rpm from a throttle blip)
Can still have a vacuum leak also. Not a huge fan of looking for them with flamable stuff.
Raw (unlit!) propane from a bottle works too, no mess either.
Can still have a vacuum leak also. Not a huge fan of looking for them with flamable stuff.
Raw (unlit!) propane from a bottle works too, no mess either.
12-04-2011, 05:45 PM
#4
well, I tried using starting fluid and sprayed around the usual culprits (intake, throttle body, vacuum lines, even the cruise control lines) but it never reved up. I sprayed it into the air filter just make sure it would effect it and it did rev up then. Im begining to wonder if the egr is the problem.
Throttle doesnt feel sticky. Clean the throttle body thinking it was the problem, but no change.
Throttle doesnt feel sticky. Clean the throttle body thinking it was the problem, but no change.
12-10-2011, 03:12 PM
#5
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"IAC counts" is a theoretical number/position of where your IAC valve SHOULD be sitting. It's what the PCM is demanding the IAC to do. I think your IAC valve is stuck and therefore cannot idle down to requested idle speed of 750. I've seen this many times. Quick test - pull IAC valve out. Manually pull the plunger outward. Reinstall IAC leaving the electrical connector unplugged. Restart car with accelerator slightly depressed. If car will not idle, this proves the IAC never hit "0 counts" or "closed position", because you manually closed IAC.
Hope this helps.
Hope this helps.
12-10-2011, 08:24 PM
#7
Unlikey, as you don't even have EGR on your car. Remove and inspect your entire PCV system.
"IAC counts" is a theoretical number/position of where your IAC valve SHOULD be sitting. It's what the PCM is demanding the IAC to do. I think your IAC valve is stuck and therefore cannot idle down to requested idle speed of 750. I've seen this many times. Quick test - pull IAC valve out. Manually pull the plunger outward. Reinstall IAC leaving the electrical connector unplugged. Restart car with accelerator slightly depressed. If car will not idle, this proves the IAC never hit "0 counts" or "closed position", because you manually closed IAC.
Hope this helps.
Hope this helps.
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12-11-2011, 11:27 AM
#11
Intimdator02SS.
You're a genius. It worked just like you said. I screwed it out and put it back in. The car would not idle without me giving it gas. I backed it in about 2 screws and it would idle. I had the electrical connector unplugged both time. with my scan tool, I could watch it "turn" the iac valve, with no success because it was unplugged. I am going to put the new part on today. thanks again
You're a genius. It worked just like you said. I screwed it out and put it back in. The car would not idle without me giving it gas. I backed it in about 2 screws and it would idle. I had the electrical connector unplugged both time. with my scan tool, I could watch it "turn" the iac valve, with no success because it was unplugged. I am going to put the new part on today. thanks again
Next time you're looking for help and it's NOT on the car in your sig, at least list what car you're working on in the post!
12-11-2011, 04:27 PM
#13
Next time you're looking for help and it's NOT on the car in your sig, at least list what car you're working on in the post!
02-04-2012, 05:33 PM
#17
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Intimdator02SS.
You're a genius. It worked just like you said. I screwed it out and put it back in. The car would not idle without me giving it gas. I backed it in about 2 screws and it would idle. I had the electrical connector unplugged both time. with my scan tool, I could watch it "turn" the iac valve, with no success because it was unplugged. I am going to put the new part on today. thanks again
You're a genius. It worked just like you said. I screwed it out and put it back in. The car would not idle without me giving it gas. I backed it in about 2 screws and it would idle. I had the electrical connector unplugged both time. with my scan tool, I could watch it "turn" the iac valve, with no success because it was unplugged. I am going to put the new part on today. thanks again
