• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

**FIXED!** Fixing One Problem Created Another...

CSteen85

CSteen85

New member
I was really proud of myself. I had figured out a problem and thought I fixed it, all by myself.
I was getting an SES light and the scanner said it was po171 - vacuum leak. I found out exactly where it was coming from. The vacuum line coming from the throttle body to the fuel rail was completely cracked. As a result, I was getting the SES light and a slight bouncing idle.
I drove to a GM dealership and ordered the part. It came in this morning and I replaced it myself. The old one I pulled off basically came out in pieces. It was completely corroded and the replacement was easy as pie.

I was sooo psyched and started the car. Everything was fine, it seemed to be running well and the RPMs were steady. I gave myself a pat on the back.

About an hour later (after washing the car), I drove about 7 miles, parked, ate lunch and then got back in the car to start it. It started, the RPMs were all over the place and then it died. I started it again, the RPMs were still bouncing, but it held and didn't die again. Most ironic thing is the SES light went out on its own and it drove just perfectly.

A little later (about 30 minutes ago), I started it and it was much better. Just a little higher than usual (idling about 1,000 RPMs instead of the normal 700 RPMs). But it seemed like it was coming down a little as it warmed up.

I had assumed I fixed the vacuum leak and all was well, especially since the light went away. What could the problem be now? Was it just some spontaneous thing? I don't understand what the issue could be. I have no lights on in the dash at all at this point.

Any help will be greatly appreciated.
Thanks!
 
Last edited:


Re: Fixing One Problem Created Another...

i would try cleaning your MAF, if that doesnt help it could be bad
 
Re: Fixing One Problem Created Another...

CTKGP09 said:
i would try cleaning your MAF, if that doesnt help it could be bad
Click to expand...

Sorry, I'm still learning, but thanks for your reply. Can you tell me exactly where the MAF is or how to get to it? What should I use to clean?

What does MAF stand for?

Thank you!
 
Re: Fixing One Problem Created Another...

Mass Airflow Sensor. its the black plug on top of the throttle body. i believe there are cleaners out there but im not sure on whick ones to use seeing as i just replaced mine. you could probably search and find it on the forums because i know its on here somewhere
 
Re: Fixing One Problem Created Another...

could also still be a vac leak did you replace the whole vac line or just the damaged areas
 


Re: Fixing One Problem Created Another...

LOL ok just checking The maf seams next best place to try you can disconect it and see if it runs any better or worse
Try sprayin it with maf cleaner might work my guess you you will be seeing another code pop up shorty
 
Re: Fixing One Problem Created Another...

TorqueAutoMotiv said:
LOL ok just checking The maf seams next best place to try you can disconect it and see if it runs any better or worse
Try sprayin it with maf cleaner might work my guess you you will be seeing another code pop up shorty
Click to expand...

Should I disconnect while it's running? Is that safe?

Also, can I use WD-40 to clean the MAF sensor or only to check for more vacuum leaks? I'm going to take a look today when I get home from work.

If the car shuts off when I disconnect the MAF sensor, does that mean it's still good? If it runs better, that means it's bad?

It's just idling a bit high now at 1,100 rpms instead of the normal 775.
 
Re: Fixing One Problem Created Another...

if you disconnect it while its still running and the car runs BETTER than it was when it was hooked up then your MAF is either dirty of dying.
 
Re: Fixing One Problem Created Another...

see if theres any debris on the wire element inside also check "not sure if your top swapped or not" theres a vac line under the blower on the lim "if your setup with a supercharger"
 


Re: Fixing One Problem Created Another...

Can one of you fine gentlemen tell me which one is the MAF? I think I'm in the general vicinity and if I had to guess, I'd guess it's the one on the upper right, but I wouldn't bet my life on it. Also, what do I use to take it off? It looks like it's neither a phillips nor flathead screw.

http://img535.imageshack.us/img535/7448/mafh.jpg


Note: Thank you for your patience. I swear, I will find a way to give back to this community! Thank you!
 
Re: Fixing One Problem Created Another...

its the one on top closest to the inlet of the throttle body. its also the biggest sensor in the throttle body.
 
Re: Fixing One Problem Created Another...

:th_laugh-pointup: what he said just unhook the connector and see what it does
 
Re: Fixing One Problem Created Another...

The connector is the one in your picture with the pink wire on the right.
The screws are security torx (I forget which size). You need a torx screwdriver or bit with a hole in the middle of it. Or, you can also use a dremel bit and ground away the pin in the middle of the head of the torx screw.
 
Re: Fixing One Problem Created Another...

BDEGhost said:
The connector is the one in your picture with the pink wire on the right.
The screws are security torx (I forget which size). You need a torx screwdriver or bit with a hole in the middle of it. Or, you can also use a dremel bit and ground away the pin in the middle of the head of the torx screw.
Click to expand...


Thank you!! I have to see if my brother has a torx screwdriver for me. I'll report back.
 


Re: Fixing One Problem Created Another...

autozone sells those tips cheap. i had to get a set when my MAF went bad. definitely easier than a dremel i would assume
 
Re: Fixing One Problem Created Another...

Update:

I went to Auto Zone, bought MAF Cleaner, a torx security screwdriver and I came home.

I took off the sensor and it didn't look too bad. I couldn't see the exact color, because it was getting dark outside, but after I sprayed the crap out of it, it looked shinier.

I reinstalled everything and waited to let it dry. I have not started the car yet. I'm really excited to, but nervous. I hope this fixes my issues!! I'll report back.
 
Re: Fixing One Problem Created Another...

So, it definitely drives even better than it did with an overall smoother feel, but I'm still idling a little high when the engine is cold, at about 1200 RPMs.
After I drove about a mile to the train station, I put it in park to wait for the train and the RPMs were floating between about 600-800 RPMs, but it felt a little shakey. It feels like they're holding steady around 800, then suddenly drop to 600 then climb back up to 800.
Other than this idling issue, the car seems to run just fine. The only other thing I'm concerned about is I think my thermostat is stuck open. The temp doesn't seem to get any higher than about 140 degrees. I'm constantly running pretty cold ever since I had the system flushed and a new t-stat installed.
I could also have an air bubble, because every once in a while, the low coolant light comes on. It never stays on for more than 2 minnutes at a time, but the coolant levels are full.

Is there anything else I should check besides MAF? I don't even know how big of an issue my idling is, because I've only stalled once and it was before I cleaned the MAF, right after I fixed a vacuum leak.
THAT's what I'm most confused about. Why would fixing a vacuum leak cause me to stall after starting the car? I changed a line that was completely cracked an disintegrated.

Thanks again!
 
You must log in or register to reply here.
Back
Top