Code 48 WTF? Please Help

[bajaranger88]

'90 Ranger 2.3 Manual. The CEL is on and I get a code 48, according to the tech library it's a "High flow unmetered air (check for large vacuum leak, inlet hoses etc.)" The inlet hose clamps are tight and has no obvious holes. Vacuum gauge says 18in HG(good). I have read and searched hundreds of threads and found not one reference to this code. Help with ideas please, I thinking possible faulty Mass Air meter. Thanks

 

[Bryan22]

start checking for vaccum leaks.

 

[bajaranger88]

But my vacuum gauge says I got good vacuum and the code says large vacuum leaks.

 

[Bryan22]

check the hoses and connections from your airbox to the throttle body for leaks and cracks.

 

[firefighter]

Even though you have good vacume, you could still have a leak. If you have one of thoes lil propane torches, blow the propane with out lighting the torch neer the intake hose's and probable sources of the leak. It will make the engine run at a higher rpm when it suckes in the propane.

 

[firefighter]

Check for vacume leaks with one of the propane torches. it will make the engine run faster when it suckes in the propane. Just done light the torch, because it wont give you raw propane and burnt sensors dont really help the situation much

 

[bajaranger88]

First of all, thanks thats a good idea, I think I like it better than using brake clean. I'll give it a try. I know that you can still have a vacuum leak and have good vacuum, however it says major vacuum leak and what I consider a major vacuum leak would certainly show on a gauge and probably be quite noticeable at idle.

 

[bajaranger88]

Ttt

 

[Bryan22]

did you figure anything out? Like i said before, if you have a loose hose clamp, or a rotten rubber connection between the MAF and the throttle body, that would cause a lot of 'unmetered' air. Since the MAF is what 'meters' the air.

 

[bajaranger88]

bryan thanks yeah i visually inspected everything before I even posted the thread, but I m going to try the propane trick and see what that does(not expecting much)

 

[Bryan22]

good idea. you never know until you go try

 

[feellnfroggy]

On the drivers side of the lower intake in the '90 is an attachment with three small hoses going in, one runs o the fuel rail I think. Anyways , its easy for these to get loose. Also the temp sensor on the airbox could be loose, but doubtful its the prob. the pcv vavle hose. the brake booster hose, also the egr vacuum hose. It runs to the pass fender well near the fire wall, has one runnin in and one running out.


Theres a buncha vacuum hose.

 

[bajaranger88]

Well after a good examination I can't find any vacuum leaks. The propane idea doesn't work because t he fan just blows it away.lol all vacuum lines appear to be good. The air charge temp sensor(bottom of the air box before the filter) is not hooked up but I can't see how this could cause this code since the code is for un-metered air and this is obviously before the MAF sensor. What does anyone think about blown head gasket between cylinders or cracked head for a cause....or anything else......I'm still gonna try some brake clean too check for leaks. This sucks I can't smog with the damn CEL on.

 

[firefighter]

. Also the temp sensor on the airbox could be loose, but doubtful its the prob.
Theres a buncha vacuum hose.

That's total before the MAF so how in any way could it throw a code?

 

[locovaca]

That's total before the MAF so how in any way could it throw a code?

Because it's vacuum driven and any sort of problem with it would cause a vacuum leak.