well i found that i am missing a peice from this PITA system. my neighbor says its some kind of heat resistant paperlike tube. it goes there



looking at my shop manual it could be called the HAI Diaphragm.

if anyone knows where i can get one of these or what its called or any other information related to its function i would really appreciate it.

thanks

Parker

oh and that tube on the bottom goes to the exhaust manifold and just above that tube there is an identical one protruding from the air intake hose

 

sometimes they have them in the autoparts stores in the "help" section where the door handels and window crank arms and such are.

 

awesome thanks. do you know what they are called so i can just ask for one?

 

i have always known it as the heat riser tube. dont know if thats the actual name though. tell them you need the shiny metal tube that goes from the exhaust manifold to the air intake.

 

I know carbs have to be kept warm so they don't freeze up, but is the 4" mini dyer-duct really going to make much of a difference, granted it extends towards the exhaust manifold. My memory is kind of foggy on this as I sold my '89 2wd 3 years ago.

 

well from what i have read and heard it speeds up the warming process. i live in washington so we get some cold mornings and my rig spits out crazy amounts of white smoke for 5-10 mins before idling down. my neighbor told me this would speed things up a bit

 

normally just called the "pre-heater duct" or "heat-riser"; and I'm willing to bet that a guy at the parts store will have no idea what you're talking about unless he's an old school guy that know his stuff good, lol. You might have to just show him in a repair manual, cause even if you show him on the truck, he still might be

I had to teach my manager at Advance Auto Parts when I worked there what it was and what it did! The freak'n manager!

Basically, it's just a corregated (spelling) tube, most of the time with an aluminun exterior coating, that runs from the top of the exhaust manifold to the bottom of the intake tube; just redirects in the intake to pull heated air right from around the exhaust manifold when vaccum accuates that pluger you circled

 

I'm sure you could find something that will work that's not OEM/OEM replacement (ie: metal tubing). Then there's always the dealership.

 

naw, they sell perfect replacements at parts stores (in the "help" section as Ezrider explained); they have several sizes, all you have to do is match one up with the ID of the openings on your truck; no need to go to the dealership for something you can get for $5 at the local parts house

 

Personally, I've removed any of these from any vehicle I've had. Something that conducts heated air into the intake is horrible for gas mileage. I've found that a properly tuned carbed motor in good condition doesn't really warm up quicker from one of these, and like I said, it hurts gas mileage once it is warmed up. stock disclaimer of it's my $.02

 

right on thanks a bunch guys! i will be stopping by napa today. hopefully it will help my smoke problem.

thanks again

 

smoke problem?

I hate to say it, but I don't think the absence of that tube will cause any smoke...

 

well its just when cold and its white smoke and it just pours from the tailpipe. only lasts untill engine is at normal temp. i dont believe im burning oil. what causes white smoke?

 

cold weather and consdensation maybe?

every vehicle does it; even new ones; it's just something motor's do in cool weather...

so long as it's more like steam and it's dissapearing not too long after coming from the tail pipe, I'd say your safe, but if it's a lingering smoke that leaves a trail behind you, then a little something more than gas is burning... or too much gas...

 

well... it lingers for awhile i suppose. but like i said only for awhile. and it is a lot of smoke. like seriously alot. i am not losing any oil tho so im thinking antifreeze? how can i tell?

 

Have you checked to see if your oil is clean? I hope its not a headgasket issue. Pull your dipstick and seeif there is any milkshake looking stuff on it.

 

Total misinformation.

They should only draw warm air from the exhaust manifold until the engine warms up.

 

nope oil is good. it had batter not be a HG cause i just bought the truck with 22k on a rebuild. how can i test for burning antifreeze? i have read that it burns white

 

the piping called 'heat riser duct' though I've also heard it referred to as a 'stove pipe'. It does not cause the engine to warm up any quicker than without. It's only purpose is to get warm air into the carburetor as quickly as possible to reduce emissions during warm-up since the warmer air will help the fuel remain atomized. Once the engine has warmed up sufficiently, there is no need for warmer air to aid fuel atomization so the diverter flap in the snorkle closes the riser and opens the snorkle to ambient air from the engine compartment.

 

... and I feel we have fully explained what it does and why it does it

point is, it's not 100% needed for the running of the truck, but if it bothers you not being there, then you know what to do...

I've never purposefuly ripped them off a past vehicle, but I'm guilty of never replacing one that just fell apart due to old age; I saved the $5 and didn't worry about replacing it, and no harm comes from doing to (so long as you don't go through an emmision test with a cold engin )