So you just stretched the rubber gasket around the throttle body?

 

No I didn't stretch it. I cut it to fit just like any gasket out of a flat piece of rubber. Don't know the thickness exactly, but it was around 1/16"...probably a little less.

 

Ok, I see now. Btw I went this morning to AutoZone and found the same diameter hose for the windshield washer fluid and put it on, works fine now.

 

Hey Kenneth,
Just wondering how you're making out. Did you do the fuel pump leakdown test yet?

 

Hey rockp2, I finally broke down and took it to a reputable local shop and they found various vacuum leaks. 1 small one at the lower intake, larger one at the upper intake, hose leak at the firewall and the temperature control unit for the heat and A/C has a leak. They fixed the one hose at the firewall and that brought the long term fuel trims for 1 and 2 down from +25 at idle to +8 and at highway speeds down to +7. Gas mileage seems to have gotten a heck of a lot better.

 

Glad you got it all worked out! Yeah, there's all kinds of places these trucks can get vacuum leaks from. Did they find them by smoking it or using propane? I'm guessing smoke because it's faster. I broke down and bought a smoke tool around 4-5 years ago I think.

 

They used propane. He quoted me $600 to do the upper and lower intake gaskets. I'm really surprised in the difference in the fuel trims from replacing the 1 hose. I looked and couldn't find where that hose went to. Hopefully I won't get anymore random misfires.

 

A couple of those hoses run down to a switch on the transfer case. They run near the rear top of the engine and I've seen them be rubbed thru by the firewall. Especially if the motor mounts are (not saying yours are!). You have to take a hard look at replacing the LIM gasket soon if it's leaking coolant on the rear driver's side. Very, very common leak and many a Blazer has had their main bearings get eaten up by coolant when the leak gets bad enough to put coolant in the engine oil. Really not a difficult job to do yourself. Last time I saw the full gasket set, I think it was around $170. But you need to do it right which may mean getting tools you need. For instance, if the LIM is not properly torqued in three stages, believe it or not, you can damage the crank. If you want your truck done in a day (or two), you might want to have shop do it. Not that you can't do it in a day, just shop has experience for all the little nuances that is involved in wrenching on an engine.

But, if you can afford to be w/o the truck for a few days for unforeseen problems, it's a great learning process (please forgive I do not know your level of experience wrenching). Probably every regular on this forum has done this job, it's that common. W/o looking I'd bet someone has written up a step by step in the tech articles.

Bottom line though keep an eye on a couple things: 1) Do you periodically need to add coolant for no apparent reason? Do you smell antifreeze? That leak is right above the exhaust manifold so it will evaporate while your driving and you'll never see it on the ground in your parking spot. (Note there is unrelated issue that would have you smell coolant and that is if heater core is leaking. A symptom of this can be if passenger floor board is damp 2) Keep an eye on your oil, if it appears milky in any way (similar to coffee w/cream) stop driving immediately and drain your oil. Coolant eats the main bearings. Check your oil cap for any "froth" underneath it.

AutoZone has a loaner tool similar to one pictured below that you can use to test if there is any coolant getting in your oil that you can't see.

The LIM leak doesn't always mix the coolant with oil, but leak can get worse and get to that point.

Just keep an eye on what's going on with your truck and enjoy!

 

Glad they got you sorted. The clue was the reduction in positive fuel trims at 2500 as the unmetered air leak became a lower percentage of overall air intake.


George

 

Thanks guys for all of your help and advice, I'm definitely going to keep an eye on things and get the intake gaskets done ASAP.