You know what I talking about. Engine warms up, idle drops to 500 RPM for a sec or two then comes back up to 750. Maybe it does it again later, maybe it doesnt. I cleaned the IAC and MAF. Replaced plugs and wires. All CAI connections from filter to throttle body are tight. So what the hell does this IAC thing do exactly. I understand it adjusts the idle but how? What sensors are involved? I'm sure these things eventually go bad but I wanna completely understand how this thing works before I start sweating the $350 it costs to replace it new. Idle problems are such a PITA to troubleshoot anyway and I dont wanna throw money at anymore than I have to. Thanks, Sean

try replacing your pcv valve first. i had a friend who had the same problem before and it was remedied by replacing the pcv valve. it doesnt hurt to try it since it cost only about $3.00.  

If you take it out, Shake the pcv valve because it it clicks then its fine, if it doesn't replace it. Just helping you save 3 dollars. :)

Ok Ok....question for everyone.  I have alot of answers for people on here, but, sometimes, I do have questions too...lol.  Ok, I found out its not my head gasket thats shot, but rather just the "little thing" on top of the throttle body...you know, its got the line with anitfreeze that runs into it as well as those two dinky little wires...im thinking its some sort of sensor(duh, lol)...i found out  where the antifreeze was commin from, after i drove it today and hardly lost any coolant.  it was comming from the line running onto this little thing im talking about....had a tiny crack in it.  also, it bubbles out a little little bit where the two wires run into it.  whats up with that? if this thing is bad, would that let antifreeze run through the intake, into the cylinders and cause it to miss? i believe ive finally found the answer to my crisis...just let me know what it is, approximate prices and such...would be greatly appreciated....lol.  thanks so much...
Jeremy

Jeremy ah something I have an answer for but first a few more questions Is this any were near the egr valve if it is I know your answer and it is a pain staking process but possible I guess I don't know were your talking about I'll look for this thing on my car tomorrow but if this thing has a crack in it and it is one of the small pressure connectors to the engine this would tell you that you need a new temp sensor because the engine might be running a little hot and the coolent itself was under a lot of pressure and heat and it tried to expand in the small port and wound up cracking this thing. If it has two wires running to it then it would be a sensor and the crack in it could mean a couple of things either that the pressure in the block cracked the coolent connectors and first before it did that tried to find an easier way to releive pressure and cracked your head a little in one of the pistons and is letting coolent into one of the head ports creating condensation and making the engine mis fire once and a while this would screw you totally you could either tig weld it and have the cracked surface machined to meet specs or get a new head. which ever you prefur but if not then the coolant is some how leaking from the crack into an air intake in a sucktion created by one of the vacume lines and then still causing the occasional mis fire without looking at it, it is hard to tell. let me know were it is round about and I can give you a straight forwad answer later Blake >

well, i dont think its the egr valve.  the only thing i saw that was cracked was the hose and i fixed that.  i am thinking that its cracked within the sensor and allowing coolant into the throttle body and feeding it through the motor.  also, i had all the coolant come out and make that big steam cloud through the cracked hose i think.  so, if you can figure out what the thing is, its got a square surface where it mounts and it turns into a lil round thing, where the nipple is for the coolant line and where the 2 little wires run into it.  the thing is above where the intake tube itself runs into the throttle body.  if you're online right now, im getting onto msn right now...turbofanatic....my email address is turbofanatic@hotmail.com, add that to ur msn thing and my name will come up.  look for me maybe we can talk bout this in messenger. later...and thanks
Jeremy

Well, whats up? Today I went to a junkyard where I'm good friends with the owner, he let me pick up a throttle body off a 95 Se, the entire unit for 50 bucks.  Not to shabby i thought.  Plus I didn't have the money on me right there and he said I can pay him back whenever I get the chance.  So my ex's boyfriend is on his way right now to get his gasket material, I'm making a gasket for it and puttin it on there.  After I take her for a spin, I'll know if solved my problem.  I believe I had an internal leake in the sensor that was allowing coolant to drain into the throttle body and run it through my motor, causing my misfire.  I thought it was the head gasket because they have the same warning signs, so, Blake, you may want to take this into consideration...I may have misdiagnosed your problem.  Just check it out and let me know what ya find.  This is alot simpler and allows you to take the throttle body and play with it if ya want to, such as getting it bored, etc.  I'll let you know what I find.  talk to ya later
Jeremy

jeremy Ok I looked over my head gasket really well and found a crack in the number 2 cylinder I took the air gun and air passed right through it so yes jeremy it was the gasket I bought a new one and it came bent so I had them order me a new one I found that my water temp sensor was broken off to but my engine light didn't come on ? replaced that though had the head ground to a little above minimum specs so if it happens again I still have a little breathing room. have fun with your throttle body later Blake >

Thats interesting. A Ford truck? defenatly tell us how it goes. Maybe do a 0-60 test before and after? (leting the engine warm up in both tests of course)

yup 351 detroit engine same match up bolt pattern and all but the only funky thing is you have to get the gasket to fit some how because the inner ports don't match the same the deisel ones have a thicker inner walls but they fit none the less I'll try it on my f/150 this weekend. let you know later Blake >