92 Idle problem
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92 Idle problem
My 92 Bronco 5.0 also has some issues with idle.
It takes far too long to come down from a high idle when I release the pedal or come to a stop. I have replaced the TPS ( do to a check engine light, that’s gone now, took it to have it tested at the store and they said that was the problem. ) and IAC.
I disconnected the connector to the IAC and the engine barely runs etc.. so it is working properly… ALso disco'ed battery for pcm..
The throttle plate stop screw, it at this point is not even touching the plate. I also notice now that the temp gauge is not even getting close to warm..tomarrow I will be changing the thermostat..
If anyone has any others ideas it would be greatly appreciated.
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From: south eastern Pa.
i don't know if you read my thread, but i have some of the same problems.i replaced the iac last week because of a code that came up after i had drained the batt. from leaving the lights on. She was running fine then i had this idle problem appear. I have now checked all of the grounds and tried to adjust the idle , because right now when i let off the gas it doesn't come down and when i come to a stop it takes 3 or 4 sec. for it to drop from 1000to about 700. It's starting to drive me crazy. I can only sugg. that you check your grounds and chek for a vacuum leak, I can't find the issue but maybe you'll have better luck. Did you get your iac from Ford. I replaced mine a couple of years ago with a unit from the zone and it wasn't any good. So i used the ford this time,costs more, but it's calibrated right. also, have you checked your ign. module?
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92 Bronco 5.0 EFI standard
I have read your thread also and was wondering if there was anything else. I did get my IAC at the zone, but when I disco it, it does almost kill the engine so I asumed it was working fine.
After I posted I was reading my ford book and it talks about an EGR valve that can cause this kind of problem and after reading more there are serveral things that can cause idle quality, such as...
BOO switch ( which is a brake on and off switch and I do have a pressure drop when applying the brakes) or the power steering switch or knock sensor...
What ign mod are you refering to?
So today I will be testing these things to eliminate them
I have read your thread also and was wondering if there was anything else. I did get my IAC at the zone, but when I disco it, it does almost kill the engine so I asumed it was working fine.
After I posted I was reading my ford book and it talks about an EGR valve that can cause this kind of problem and after reading more there are serveral things that can cause idle quality, such as...
BOO switch ( which is a brake on and off switch and I do have a pressure drop when applying the brakes) or the power steering switch or knock sensor...
What ign mod are you refering to?
So today I will be testing these things to eliminate them
Last edited by Peanut_THumper; Oct 26, 2004 at 05:56 AM. Reason: forgot to add something
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From: Gateway to the West
You may have lost the temp sensor for the PCM. If the PCM gets no reference on water temp it will try to maintain the higher idle until it gets the proper reading. The sensor that feeds the PCM should be threaded into a fitting in the lower intake manifold just above/behind the water neck for the thermostat.
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From: south eastern Pa.
Have You Checked For Any Other Codes. I Had My Truck Back On The Scanner This Morning . 2 Things I Have To Replace The Knock Sensor And The Egr Sensor. They Didn't Show Up Last Week But Now They Do. The Temp Sensor Is Also Something To Look Into On Your Vehicle. I Would Look Into Checking On A Scan Tool. Lots Of Luck And I Hope Our Problems Come To A Sudden Death, Sometimes I Feel Like Shooting Her Like A Broken Horse. Lol
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Ok here is what I ended up with...
I ended up taking it in to get it coded and after they realined it they said it was good...
went to get it, drove off and it started idling high again.. went back showed them...after all that it was the throttle body.. I have to order that and it is about $350, the good news is that after I put in the throttle body they will recheck it for free... so you might want to check that and the cable. when it starts idling high try pushing on the thrrottle and see if it idles down, if so then that will be your problem...
And i agree with you on wanting to shoot her !!!Thanks for every ones input.
I ended up taking it in to get it coded and after they realined it they said it was good...
went to get it, drove off and it started idling high again.. went back showed them...after all that it was the throttle body.. I have to order that and it is about $350, the good news is that after I put in the throttle body they will recheck it for free... so you might want to check that and the cable. when it starts idling high try pushing on the thrrottle and see if it idles down, if so then that will be your problem...
And i agree with you on wanting to shoot her !!!Thanks for every ones input.
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From: south eastern Pa.
I'm Glad You Found It. I Also Had Some Luck. Replaced The 2 Sensors And The Truck Ran Better. It Still Had The Iding Problem Though. It Turns Out That When I Did My Mods This Summer, The New Valve Covers, Because Of The Oil Cap, Were Creating A Positive Vacuum In The Motor Which Kept It From Idling Correctly. So We Replaced The Cap With A Vented One And Put A K&n Breather On It And It Is Running Perfectly. Thank God, With The Amount Of $$$$ I Put Into It This Summer I Am Breathing Again..... About Your New T.b Are You Buying Stock Or The Bbk Unit . If That Is What Ford Is Charging Get The Bbk.i Have The Twin 56 Mm, That Alone Will Probably Give You 5-8 H.p.good Luck
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Lead Driver
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From: Gateway to the West
WHat exactly went wrong with the entire throttle body? Did they tell you? Its a pretty straight-forward component to "fail".
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Well I actually thought that was the problem, but like you said they don't usually fail, but if you were to push on the accelerator when it is idling hi it will come down ... and after all their adjusting it still idled like a mad dog.. and then they agreed with me..
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From: south eastern Pa.
I'm Back Also. I Thought I Had My Problem Solved Also, Then The Idle Prob Came Back. So, Back On The Scanner It Went And No Codes Came Up But On The Run Test It Said Idle Is Too High And Theo2 Sensor Is Not Switching From Closed Loop To Open Loop. The Idle Is Strange Because In Park It Idles At About 1000 And In Drive It Is Idling Between 550 And 750. When Icome To A Stop The Idle Will Remain High For 3-5 Seconds Then Drop, Some Times Almost Dying. I Replaced The O2 Sensor Today And No Change. So I'm Back To Square 1 So If Anybody Has A Thought I'd Apprec. It.good Luck Thumper, We Need Some.
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From: Auburn/ Opelika
Mine has this problem as well and I haven't been able to figure out the source...yet. Someone told me it could be the TPS, should I replace it? I've already replaced my IAC and that helped some but I still get the high idle you guys got. -Bill
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From: Gateway to the West
Idle control is the job of the IAC. Plain and simple. Vacuum leaks, EGR leaks, or malfunctioning sensors around any of these air handling systems will adversly affect idle because the PCM will try to compensate for the incongruities by adjusting the properly functioning parts. Since there are no codes being generated, then I would suspect a leak or leaks somewhere in one of these systems.
rudder9,
The numbers you gave for curb idle and in-gear idle sound right. Maybe a touch high like a small vacuum leak or sticking EGR but with no codes, I'd lean towards the leak.
rudder9,
The numbers you gave for curb idle and in-gear idle sound right. Maybe a touch high like a small vacuum leak or sticking EGR but with no codes, I'd lean towards the leak.
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Try pushing on the accel to make it idle down ..my screw was not touching either ..if that works it maybe the throttle body.I have replace the tps, IAC and this is the last thing to try..
I had to order a new throttle body, there was no chance of getting one at the junkyard here..
I had to order a new throttle body, there was no chance of getting one at the junkyard here..
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Originally Posted by rudder9
I'm Back Also. I Thought I Had My Problem Solved Also, Then The Idle Prob Came Back. So, Back On The Scanner It Went And No Codes Came Up But On The Run Test It Said Idle Is Too High And Theo2 Sensor Is Not Switching From Closed Loop To Open Loop. The Idle Is Strange Because In Park It Idles At About 1000 And In Drive It Is Idling Between 550 And 750. When Icome To A Stop The Idle Will Remain High For 3-5 Seconds Then Drop, Some Times Almost Dying. I Replaced The O2 Sensor Today And No Change. So I'm Back To Square 1 So If Anybody Has A Thought I'd Apprec. It.good Luck Thumper, We Need Some.
My throttle body is in an I will pick it up today and get it reset on the computer side tomarrow.. and then I will let you all know how it went..
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From: Auburn/ Opelika
I think it's a huge vacuum leak, it started being super sluggish today, not good. I recently replaced the EGR tube so I'll start there first and then the other connections.
Now that you mention a new TB, I remember having it looked at awhile back and the mec sprayed the TB with cleaner which worked until the spray wore off. How can I lube/ fix the TB more effectively than spray?
Now that you mention a new TB, I remember having it looked at awhile back and the mec sprayed the TB with cleaner which worked until the spray wore off. How can I lube/ fix the TB more effectively than spray?