when truck is at running temp. and placed into park or neutral the idle speed is around 1700 rpms, seems excesive to me - not sure why this is happening.
any help is appreciated.

iac(idle air control) is likely the cause remove it from the throttle body and give it a good cleaning with an old toothbrush and carb cleaner.spay inside the hole also,hell might as well do the whole throttle body.Just out of curiosity do you have a k&n filter, if you do get rid of it.that seems to make it happen alot.ever since i got rid of mine i havent had a problem.

What cuervo said...good post cuervo.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

throttle body cleaner does wonders. as for the k&n, it actually works. we have a dyno at school and they decided to do a test, same car both the drop in k&n, and the k&n intake set up. the drop in gained about 1 hp, i know not much at all but as long as you follow the instructions on the recharge kit. get this the whole assembly actually gained all of 2-4 hp. the instructors were saying the assembly's really wont do much for the price unless youre gonna do some major work. in my opinion, 300-400 dollars for 2-4 hp....it would be smart to just pass on it. but i did have a similair problem, i needed a new iac. it solved it, and price wasnt that bad, about 49 dollars.

Julio it may have added a few horsepower, but like you said for the price it aint worth it.Another thing the oil that coats the filter gets sucked into the throttle body,i know from experiance.i had 2 k&n filters one ready for when the other was dirty.i would immediatly clean it then let it dry then spray on the oil and leave it.no matter what i done the oil will still get sucked in. plus you know something is wrong when they say right on the box the dirtier it gets the better it works.You know what that means,It means that the holes in the filter are larger to allow more air in .(along with dirt and oil) and as it gets dirty it fills in those holes and filters more like the regular filters do.
maybe you can talk the intsructors into doing one of those kits on a jeep and see how it works.jeep has built in cold air induction ,but it gets the air from ouside the engine compartment. then do some butchering and put a smooth pipe in where the ribbed part of the stock tube is.test different methods and see which performs the best.

what year jeeps have this? mine is a 95 with the 2.5, and it has a restrictive box with a little air hole right in front of the radiator.

Julio...It ain't restrictive! PERIOD! Maybe to your eyes it looks restrictive but it IS NOT!
Think of it thisaway. WHY would the manufactorer deliver a restrictive intake system? When a bigger hole up there would cost the same? YOUR intake system is engineered to work EXACTLY for your engine! You cannot make it better.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

Thank you Bj couldnt have said it better.My jeep has it and it is great. why would you want to put something on that sucks oil into your tb is beyond me. do the little experaments i mentioned,go to a salvage yard and get several of those box sytems and try those different ways and see which works best.I promise the one that works best wont cost you 300 dollars.
besides hp is for road use,you use more torque than hp off road.torque is what gives you take off power,and pulling power. most of the time you aint getting to the point where horsepower kicks in,you are not traveling that fast.the only time i seen when high horsepower is needed is when blasting through deep mud,the faster the wheels turn and keep traction the better.

I agree, at 4500-5000 RPM (6 cyl) the stock system gets restrictive on the line of 1/8-1/2" of mercury. Some is the paper filter, some is the intake tract. You can get a fractional increase in power by minimizing intake tract restriction and increasing the laminar flow through the tubing. You can change filters put in smoother bending pipes with smoother pipe sidewalls... ETC.

But is it worth a couple hundred bucks to get 4 HP? The results I got on a dyno, didn't even show that much (I kind of wonder if you were running the same conditions between runs, with multiple runs for averaging). Even if cost wasn't much of an issue, have you wondered how a K&N flows more than a paper filter even though it is the same size with less pleating(less flowing surface area)? Larger holes. Larger holes means more dirt passing, which means tearing up the cylinders. When I took my engine out of my jeep at 187K miles, I had been running a K&N for almost 30K miles, washing and oiling it every 5-10K miles. I had .028" of wear on my worst cylinder and .024" on my best. I've torn down engines of friends with 200K on them with stock filters and boxes that are usually on the line of .010-.015", almost half the wear. The stock piston to cyl. wall clearance on most motors is .0015-.0030". Even if the filter did boost your power the amazing 15-30 HP is it worth kill the motor within 190K miles?

well, the test wasnt on a jeep. some honda car, the first time there was like a 12 hp increase, then the instructor noticed the guy left the hood up. and thats how they got like 4 or around there. i understand all arguments, if the manufacturer designed the engine with a higher flowing intake system, they would have put it in from the begining. now for my end of it, lets say a stock box would cost the manufacturer lets say $20. and the higher flow, $50, they are gonna put the box in, for both emissions, noise, cost. they save those 30 dollars per vehicle. your average car buyer doesnt want to hear the engine noise, road noise etc, and we all know a high flow intake makes noise. thats were the intake people come in. personally, i know one can be made for way less than 300 dollars, but it wont be legal. so most people opt to pay the high price so they arent swapping things everytime they smog.