Iat

What kind of performance diff would i get if i moded the IAT sensor? it's a 95 4.3. CPI, working on custom intake.hp improvement from both?

It does nothing on our engine.

Leave it at its stock location.

Any changes with be compensated for and removed by the computer.

Net result is nothing.

i don't know if the sensor is causeing it or not but if i come to a stop light the engine rpms fall lower then normal and then pick back up. it only happens after comeing to a complete stop. could the sensor be doing this or something elise. would moving it change anything?

You have to remove the IAC (Idle Air control Valve) and spray it down with throttle body cleaner and scrub it with a toothbrush.

Also spray the hole inside the engine down and scrub and rinse it out with throttle body cleaner also.

ok. i'll try that. the only thing is it only does it when its hot. if its cold its fine.

Clean your IAC vlave.

http://www.tweaknews.net/decarbon/IAC.JPG

will do. its raining here now so i'll do it when i get the chance.

If you still have your stock air-box there is another hole behind the air filter. Your sensor will get a colder "denser" reading and tell the computer to dump in more fuel. In theory at least. I thought it would kill my milage but so I'm at 250 miles using less than half a tank, ( better than usual ) .

i have just a cone in there now but in about a month i'm making a custom intake so i'll put it in there now. i'i luckey to get 280-250 miles on on tank of gas. all city driving. do you think somthings not right or is that good milage?

I used to get about 340 before I started looking for a pump before the mods, but I looks like I'm going to do better than that. All I've done, besides moving my IAT, is drill some 1" holes in my air box and installed some 1.6 lift roller tip rockers. I'm at 165,000 miles and I have a 26 mile commute to work mostly hilly and curvy country roads.

have you gotten any more power by adding the 1.6 lift roller tip rockers? brand? price? did you install them?

I noticed a bit of power increase from the rockers. They were Comp Cam and were free. I work at an engine and transmission remanufacturing plant that throws a lot of stuff away. I did think about bringing several sets home and selling them on e-bay.
They were fairly easy to install. I have screw in rocker studs that have a positive stop so I didn't have to do a valve adjustment as opposed to press in studs. If you are not sure what you have you can tell by the rocker nuts. If they are 5/8" you have press in studs, 1/2" they are screw in. The most trouble I had was getting the r/s valve cover on with the rubber gasket in place. The book says to remove the A/C compressor but if you have a little patience you don't need to.

what year is your blazer? do you no what they cost new?

Mine is a 95 and I'm pretty sure you have the screw in studs. Looks like Comp Cams sells them for $250.00 as a kit (pushrods, nuts, balls alsoz).

do i have to remove the head to change the pushrods?

No. They will slide up through the top of the head, just make sure the new ones are seated in the top of the lifters. When you tighten the rocker nuts down you should be able to rotate the pushrods with your fingers and should feel a little drag. Oh.. You should buy some assembly lube also and apply to all parts that will have friction till your oil pressure builds up. Running those new parts dry even for a few seconds will ruin them. It only took me about an hour and a half.

ok. thanks for the info. have you ever tried your truck in the 1/4 mile?

Naw...not any around plus being a primiary vehicle I'd hate to blow something and have it be down for a while.

what other mods are done to your blazer? i have a glasspack exhaust with a custom intake. future plans are to convert fan to electric and put roller rockers in with a MSD ignition system.you?

I did add a Moroso Pro-Coil that seemed to help ($1) to take it home. Thats all I've really done but a cold air intake will probably be next. I plan on making it myself, can't really justify spending $200 on a pipe with a filter.
Always looking for headers, they usually run up to 94 and after 96, don't know why. They seem awful pricey for a V-6, average price $279. I will probably run it into a single 3 1/2" exhaust and not sure on what type of muffler, many to choose from.

i know somebody sell them because i was looking into them my self and they are any where from $500 down. but you can get them for a 95.

by the way i got a chance and i pulled the idle valve and it had alot of carbon on it so i cleaned it and when i put it back in it idled up and down but then smothed out. runs good now. thanks for the help.

did you use throttle body cleaner and did you clean the hole it came out of?

I used to get about 340 before I started looking for a pump before the mods, but I looks like I'm going to do better than that. All I've done, besides moving my IAT, is drill some 1" holes in my air box and installed some 1.6 lift roller tip rockers. I'm at 165,000 miles and I have a 26 mile commute to work mostly hilly and curvy country roads.


I just filled up today and figured about 21 mpg, up from about 18 mpg.

not bad.

Also, don't use a 3.5" exhaust.

That is pretty ridiculous for a 4.3L.

your engine needs backpressure.

Just had a 4.3 come in today with a complete intake on it ( rare ) I'm going to see about polishing it up and maybe switching.

maybe a 3.5 is a little much but at least a catback.

Damn it Wilfie27! You make me feel sooooo jealous!

come to think of it...it did have some hokey grey valve covers that sat about 2" higher than the stock ones, I'll have to check tomorrow. Still looking for headers, seen a few on V-8's but never V-6.

They are out there just keep looking.

Oh..I know they are out there, I meant a pair on an engine core that we get at work. I've seen guys take V-8 headers out the door for around $20.