Ok, a bad or out of range TPS can also be the cause of a P0507 code. If you go online you can more than likely download the instructions for the scanner. Knowing the IAC counts position (or %) and the TPS angles will be a big help. The more info we can collect narrows down the possible paths we have to go down and the less time being frustrated. But you do need to get a meter to keep from guessing. A test light is also very good to have.

 

There's three hoses coming off switch on transfer case actually 4 the 4th being the one that tees in to one of the three, would anyone be able to tell me we're the three go it's a 2091 blazer 4wd ls

 

Any help would be appreciated

 

Here's some diagrams that should help.

 

Don't know if your a drinkinking man or not but I owe you a good drink ..this hand written diagram is friggin priceless, thank you very much

 

The handwritten is not mine. Got it from Captain Hook several years ago.

 

If You're not sure if the code and fuel trims are related to a vacuum hoses, You may simply block the hose that goes out of the manifold and see if that helps. That will disable a vacuum actuator and the HVAC control in dash - but no big deal, the engine will keep running, and You'll get an instant diagnose - whether it is a vacuum system leak or not.

 

I pulled hose off idle went up I plugged it idle went back to where it normally is (but still to high to pass smog) does that mean no vacuum leak ?? Hey I appreciate the heck out of ya for the learnin I'm getting from ya

 

Oh I have a buddy coming over with a meter and he's gonna check TPS ...MAF ..everything he can that's even remotely connected

 

The way fuel trims work is that you add the long term and short term fuel trims together for a given bank, making note of the sign (+/-). A positive total number for a given bank shows that the computer has to add fuel to compensate for a lean condition. A vacuum leak can be one cause as can any extra air after the MAF sensor (not accounted for by the computer) but there are other reasons. Bad MAF, bad ECM, bad connections, bad O2 sensors, ...

If it is an air leak and if it is a vacuum leak in particular, your fuel trims will be more positive at idle and less positive at 2500 rpm when the vacuum leak is a smaller percentage of the total air.

Please post all four fuel trims at idle and again at 2500 rpm, including their signs.

If it is an air leak you can find it with a good visual scan, a smoke test or by using a water spray bottle.

George