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Discussion Starter · #1 ·
Ok, so i bought my bronco and have been driving it for a little bit now. I like the way it drives, but i think there's something wrong with the motor. It seems to me that it is idling a little bit too high, and when i put it in gear the rpm's will drop down really low, and sometimes shut off. I took it to my local auto parts store. I told him about what was going on, and he told me to take the upper and lower intake's off and clean them up with a can of brake cleaner and a wire brush, like what you clean out a shotgun with. I've never heard of this being done, and i don't know if it would help or not. What do you guys think?

Matt
 

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Take it off and clean it.
How many miles are on the truck?
Use throttle body cleaner for the throttle body(duh). And take off the IAC and clean it too.
You will probley use about 4 cans of cleaner, and you probley still not get it all out. The bolts are a bitch to get to, but well worth the trouble.
If your cleaning up the engine bay you may want to paint the upper intake at this time. You really don’t need the high temp paint for it, I just used the dupl. color silver paint, 2 years ago and it still looks fresh. Check the picks in my garage profile.
It would be a good idea to change plugs, plug wires, distributor cap and rotor at this time. It makes running the wires a lot easier. Put it all back together, see how much better it runs. Then run some sea foam through it to clean out the rest of the junk.
 

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Discussion Starter · #4 ·
ok, thanks for the replies. I know this is a dumb question, but what is the IAC? I don't know much about the EFI stuff yet, i just bought it a couple weeks ago, and have only been able to drive it for about 4 days. I did take the a can of throttle body cleaner and cleaned the throttle body. It has 160K miles right now, and the bottom end of the motor was rebuilt about 5K miles ago, nothing done to the top yet. I'll get some more cleaner and take it off then. Is it hard to take off the intake? since it's 17 years old, i bet they're gonna be pretty rough to take off. Again, thanks for the replies. If you have any more tips please let me know.

Matt
 

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Discussion Starter · #6 ·
ok, i read the write up, really good info. I know what it is now. My neighbor has his blocked off. He made a plate to where it is completly blocked off. Is this good? i never asked him what it does, he just told me he had his blocked off.
 

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crank trigger
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before you remove your intake, do some simple stuff first.
check for codes (search for directions)
need new wires and plugs?
check your TPS (throttle position sensor)
SEAFOAM! kill skeeters too...bonus. then change plugs.
check yer timing.
offer gacknar some yams
 

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I don’t think it would be a good idea to take off the IAC.
Here is a pick of the upper intake off with the lower intake still on (you don’t need to take off the lower). I also replaced my valve covers with chrome ones, with new gaskets.
[/IMG]
 

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Discussion Starter · #9 ·
lol...yams? ok, i guess i'll try that before i start tearing things apart. I was thinking that since it has so many miles, and when i opened the air cleaner box while it was running and smoke was comming out of that...hole...i guess it was the EGR. That's what made me think that he was right and the intake was full of carbon.
 

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The hardest part about taking off the upper intake is removing and replacing the one far throq (ever how you spell it) bolt, on the passenger side. And the center one on the passenger side, use a 1/4 drive wrench with a long extension.
 

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crank trigger
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mtthwvn73 said:
lol...yams? ok, i guess i'll try that before i start tearing things apart. I was thinking that since it has so many miles, and when i opened the air cleaner box while it was running and smoke was comming out of that...hole...i guess it was the EGR. That's what made me think that he was right and the intake was full of carbon.
egr is really hot gasses. would prolly melt your airbox. you are seeing crankcase vapor from the PCV.
but, a somewhat dirty intake should not give you the performance probs you are experiencing. i think it is just engine management issues you need to straighten out. maybe a few ignition parts too. give it midgrade fuel.
 

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Shoot!
I just re-read your first entry.
It almost sounds like a vacuum leak somewhere.
You can remove the IAC first and clean it out, and see if that takes care of the problem first. Check all the bolts on the intake and throttle to see if any are loose. You may be sucking in unwanted air.
Cleaning the upper will in prove your throttle response.
 

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ScorpionBoy said:
SEAFOAM! kill skeeters too...bonus. then change plugs.
:toothless :toothless :toothless SEAFOAM!!!!
 

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Ex Navy Nuke
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That hole in the air filter box is from the breather filter. If you're getting smoke out of it then you either have a bad pcv valve, blowby or bad valve seals. If the bottom end was really rebuilt 5k miles ago then blowby shouldn't be an issue(the intake bolts would've had to come off for that too). I still say don't remove the whole upper intake for an idle problem, there is something else wrong.
 

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Discussion Starter · #18 ·
ok, thanks for the replies guys. I was talking to my other neighbor about it, and he told me that it's probably just a vacuum leak too. He told me to take a bottle of propane (like a torch or something) and open it up all around the openings of the vacuum ports. If there's any leaks between the motor will rev up. I'll check out what you guys have told me and see if it will help any. Thanks for the help.
Matt
 

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mtthwvn73 said:
ok, i read the write up, really good info. I know what it is now. My neighbor has his blocked off. He made a plate to where it is completly blocked off. Is this good? i never asked him what it does, he just told me he had his blocked off.
On EFI, that's not a good thing to do. The IAC is there so that the computer can control the idle of your engine, and if he's got that removed it means that he probably turned in the adjust screw on top of the throttle body to make it run at idle. (Which you are NOT supposed to do because it messes with the computer)
 

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Discussion Starter · #20 ·
ok, i didn't know if it was something you should do or not. I guess i'll just clean it up and check for any vacuum leaks then. Thanks again for the help. I know i'll have something else to ask in the future.
 
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