Idle speed dropped off
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Senior Member
Joined: Nov 2003
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From: deep in the redwoods
Idle speed dropped off
Looking for ideas/suggestions on the following:
I have a 97 F150 4.6 AT 4x4 with 95K miles. New plugs at 30K. Fuel filter has about 30K miles on it.
The check engine light came on at about 85K and my micro tuner gave me a code of "insufficent egr". I ignored it.
Lately, I've had a slight high speed miss near the top of 2nd gear at around 60 mph. I researched some threads and found the egr problem may be suspect.
I disconnected the battery, cleaned the cables and while the battery was disconnected, removed the egr and much to my surprise (and disappointment) all looked and tested OK.
I reconnected everything, and the miss dissappeared....but now it idles down in drive to about 500 rpm. It has yet to stall, but is very near stall speed.
At this point, I should mention I did not do a good job of saving the gasket on the EGR.... but it was Sunday and no chance of getting a new one, so I put it back together.
Read some more threads and decided to disconnect the battery for 15 minutes, reconnect, fire up and hold to 3K rpm for a minute or two then idle down.
It seemed to help, doesn't ACT like it's going to stall now, but RPM is still lower than the usual 625 to 650 rpm in drive.
Read some more threads, and the TPS is suspect for our trucks, but only in 2004 and newer. Mines a 97.
My wife's 2000 Explorer did the same thing (only it did die a couple of times) and I replaced the ISC. Totally fixed the problem.
Sooooo, what to do? Besides take it to the dealer? Any ideas or suggestions?
I have a 97 F150 4.6 AT 4x4 with 95K miles. New plugs at 30K. Fuel filter has about 30K miles on it.
The check engine light came on at about 85K and my micro tuner gave me a code of "insufficent egr". I ignored it.
Lately, I've had a slight high speed miss near the top of 2nd gear at around 60 mph. I researched some threads and found the egr problem may be suspect.
I disconnected the battery, cleaned the cables and while the battery was disconnected, removed the egr and much to my surprise (and disappointment) all looked and tested OK.
I reconnected everything, and the miss dissappeared....but now it idles down in drive to about 500 rpm. It has yet to stall, but is very near stall speed.
At this point, I should mention I did not do a good job of saving the gasket on the EGR.... but it was Sunday and no chance of getting a new one, so I put it back together.
Read some more threads and decided to disconnect the battery for 15 minutes, reconnect, fire up and hold to 3K rpm for a minute or two then idle down.
It seemed to help, doesn't ACT like it's going to stall now, but RPM is still lower than the usual 625 to 650 rpm in drive.
Read some more threads, and the TPS is suspect for our trucks, but only in 2004 and newer. Mines a 97.
My wife's 2000 Explorer did the same thing (only it did die a couple of times) and I replaced the ISC. Totally fixed the problem.
Sooooo, what to do? Besides take it to the dealer? Any ideas or suggestions?
Thread Starter
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Senior Member
Joined: Nov 2003
Posts: 263
Likes: 0
From: deep in the redwoods
bump and update
well, after a day or so, idle somewhat improved. Coming to a stop, idle goes down to 500 and rebounds to 600 to 625 rpm. Still low and still closer to stall than I like. And yes, A/C is on......it's FL and HOT here.
Help?
Help?
Member
Joined: Sep 2007
Posts: 40
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From: Edmonton
mine does that too it DIVES when i first put it into drive...and i dont understand why 92 5L f150
all we did was change the rear seal....hmmmm i dunno i get a code thrown everytime i accelerate till 50 km/h then it goes away?
ideas? (might help OP )
all we did was change the rear seal....hmmmm i dunno i get a code thrown everytime i accelerate till 50 km/h then it goes away?
ideas? (might help OP )