Running rich!

[deputy865]

Well my car all the sudden started to run rich. My air/fuel guage says so...

It just randomly started. No matter what throttle i am at 1% or 100%, the guage shows im running rich. The little line doesnt go back and forth like it used to. Sometimes when i start the car the RPMs go very low then come back up. Like its bogging down. I have an SAFCII but it isnt tuned for the car just yet and i didnt mess with anything. So what could be causing my problem? Its starting to affect my mileage. A 1/4 tank of gas would get me about 80-90 miles. Now it gets me like 50-70.. Im afraid to drive my car now just incase its something serious..

So what could be my problem?

I can provide any info. Pictures or maybe even video.

Shane

 

[EagleTalonTim]

Boost Leak! Do a boost leak test and fix all leaks! Also check spark plugs and gap (.28), and spark plug wires.

 

[daarkness92]

any black smoke?

 

[deputy865]

yea there is black smoke when i punch it so im told. But nothing BAD.. And what can i do to test for boost leakes? I think i have one.

Shane

 

[TuRBoTaLooN]

Are you using a wideband AF sensor? If so, you mentioned that it's not moving at all. No matter what is wrong with your car, your AF varies even if it's just a little bit. It never stays exactly the same. If it doesn't change at all, looks like you have a bad sensor. I had a similar situation where my AEM WB was reading 14.7 exactly no matter what. Turns out my little back fire after putting thing back together toasted the sensor. Put in a new one and all was well.

 

[deputy865]

It moves a tiny bit every now and then. But it doesnt move like it did before. This is my guage

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Shane

 

[TechBenchTony]

I have been having this same issue. Not trying to thread-jack. Its looking like it might by my O2 sensor going bad, I haven't had time to check it, but you might look into that too.

 

[BigSorn]

get a wideband.


a/f gauges are worthless.

but...do a boostleak test. ngk bpr6es's gapped to .28.

 

[deputy865]

get a wideband.


a/f gauges are worthless.

but...do a boostleak test. ngk bpr6es's gapped to .28.

that whole "ngk bpr6es's gapped to .28". I dont understand any of it

Today while i was driving it was just flickering up and down like one square.. And it was giving me other readings, so it is working. Im just mad im loosing gas mileage!

Shane

 

[Gstclipse69]

Ngk bpr6es are the spark plugs you should have. And they should be gapped to .028.
Air/fuel gauges arent really worth much other than to tell if your 02 sensor is working properly. I'd definitely boost leak test first. You can make a tester for $10. Just search for boost leak tester. Nothing to it, hook it up to the turbo, pressurize the pipes and listen.

 

[deputy865]

Haha well i dont need a tester to tell me i have a boost leak. I was watching my boost guage.. I would punch it, i would boost 14psi, then it would drop down to 10psi and hold there.. Sometimes when im driving and i give it a little more gas, it takes awhile for the car to "catch" and pick up speed.. Hopefully this leak wont be TOO expensive to fix..

Shane

 

[Black99gst]

Haha well i dont need a tester to tell me i have a boost leak. I was watching my boost guage.. I would punch it, i would boost 14psi, then it would drop down to 10psi and hold there.. Sometimes when im driving and i give it a little more gas, it takes awhile for the car to "catch" and pick up speed.. Hopefully this leak wont be TOO expensive to fix..

Shane

nah, it'll be free! if you can find it yourself and fix it... make yourself a boost leak tester, hook it up, and listen, it'll be their, and fix it... DONE! took ya 15-20 mins...

 

[deputy865]

Where is the most common boost leak?
Am i sure that it is just a boost leak? Because the car fluctuates in RPMs when i start it. It will go realy low (almost to the point of stalling) then it will go back up, then down a little, then back up and stay.
Also when i let off the gas, sometimes there is a popping noise up front. It makes the noise as the turbo lets off. Wtf is that?

Shane

 

[deputy865]

found out what the problem was. Its the MAF. So where can i get a new one? They wanted like $250 total at AutoZone.. On the receipt i got from the CEL being pulled, it gave a few causes..

1- Vacuum hose off, cracked or passage blocked-Engine mechanical timing condition.

2- Throttle body intake tube loose, off, or cracked

3- BARO/MAP (Manifold Absolute Pressure) defective

4- VAF (Vane Air Flow) MAF (mass air flow) sensor dirty or defective.

Thats what the sheet says.. Anything i should take a look at or should i just get a new MAF? I need to know where to get one. Not looking for something REALLY expensive.

thanks,

SHane

 

[dsm-onster]

2- Throttle body intake tube loose, off, or cracked

You said you are sure you have a boost leak. And the code from the 'receipt' told you.

 

[deputy865]

Well im sure that would be cheaper huh?

Where can i get that part? Im pretty sure i have a boost leak.. My boost guage will show me boosting like 14psi, then it will drop to like 11psi.. Loos pressure.. Im guess that would be a boost leak.

Im going to go the cheap route to start. Ill replace the spark plugs and clean the MAF and see if that helps at all. If not, then i need something else.

Shane

 

[dsm-onster]

One of your intercooler piping clamps could just be loose. Checking over your piping is free.

 

[deputy865]

I checked over ALL of my piping and tightend everything. Still does the same thing.. But while i was reading on how to make and operate the boost leak tester i came across this:

"However, when I reconnect the I/C pipe to the throttle body elbow and re-test, I can't even hold 1psi!!! When I am driving my boost will hold at 13psi and slowly drop to 10psi as I reach redline (normal with T25"

It says the psi drop is normal for the T25.. Because thats what mine is doing? Only difference is that mine just drops off.. Even when im not red lining.

So maybe i dont have a boost leak at all. So all that is left is my MAS. I found a GM MAS on eBay for cheap. Will i need anything else to run that MAS or can i just throw it on there and call it good (doubt it?)

Shane

 

[turbott]

You can make a boost leak tester for about 5-10 bux...do a google search for "boost leak test diy"

 

[dsm-onster]

I checked over ALL of my piping and tightend everything. Still does the same thing.. But while i was reading on how to make and operate the boost leak tester i came across this:

"However, when I reconnect the I/C pipe to the throttle body elbow and re-test, I can't even hold 1psi!!! When I am driving my boost will hold at 13psi and slowly drop to 10psi as I reach redline (normal with T25"

It says the psi drop is normal for the T25.. Because thats what mine is doing? Only difference is that mine just drops off.. Even when im not red lining.

So maybe i dont have a boost leak at all. So all that is left is my MAS. I found a GM MAS on eBay for cheap. Will i need anything else to run that MAS or can i just throw it on there and call it good (doubt it?)

Shane

MAF translator is neccesary. Which is around $200. The gm maf can be had on ebay for $50-60.

You could have tight hoses and still have a leak. I really am dumbfounded as to why you won't go through that troube code list you posted by most affordable first. ANY of the problems in that trouble code list could be your problem. HALF of them would show up or be eliminated with $10-15 boostleak tester. EVERY symptom you've described points to a boost leak. The chances of a maf failure vs. there being a simple boost leak doesn't merit the cost of another maf.

How to build an Intercooler Pipe Pressure Leak Tester

If you want to work on a turbo maf car, you need to have a boost leak tester.

 

[deputy865]

Alright. Im going to make a boost leak tester. I bought some hose for my vacuum lines. Im going to hook all that up again and see if that helps any. Then do the boost leak test. Cus i know i have one...

Shane

 

[deputy865]

This might sound like a stupid question. But where exactly do i hook it up at?

Shane

 

[dsm-onster]

The turbo compressor inlet .

 

[SlickPyro]

IF you are still looking for a MAF sensor try DSM Graveyard - Your #1 Source for Used DSM Parts! I needed a coolant temp sensor plug from there and it was $12 I dont think it was that bad to pay and I didnt have to go find a dsm to rip it out of.

 

[deputy865]

If i bought a DSM MAS sensor, i wont need a stupid $200 MAF-T will i?

Shane