Gain extra benefits by becoming a Supporting Member Click here find out how!

Classic Performance Products Classic Parts
American Auto Wire Classic Industries
Danchuk Catalog
Hellwig Products IncPerformance Rod & CustomJoin the Community today
Ecklers AutoMotiveNu-Relics Power Windows



Username Post: Mass Air Flow Sensor Problems        (Topic#355426)
wreakhavoc 
Poster
Posts: 64

Reg: 12-09-07
02-28-19 06:13 PM - Post#2761009    

I have replaced my MAF sensor with a brand new one twice, clean used ones twice, and cleaned the wire sensors on my original one and no matter what I do the check engine light is still on and the codes are saying the MAF sensor is the culprit and it is running too rich.

What else can I do?
2000 Express 2500 van w/350.
Thanks.




 
454cid 
Valued Contributor
Posts: 3121

Age: 46
Loc: West Michigan
Reg: 02-18-12
02-28-19 06:50 PM - Post#2761012    
    In response to wreakhavoc

  • wreakhavoc Said:
I have replaced my MAF sensor with a brand new one twice, clean used ones twice, and cleaned the wire sensors on my original one and no matter what I do the check engine light is still on and the codes are saying the MAF sensor is the culprit and it is running too rich.

What else can I do?
2000 Express 2500 van w/350.
Thanks.




What is the code? A code for something doesn't necessarily mean that part is bad. It can mean it's simply not reading what's expected.


99 K3500 RCLB


 
wreakhavoc 
Poster
Posts: 64

Reg: 12-09-07
03-01-19 05:57 PM - Post#2761082    
    In response to 454cid

  • 454cid Said:

What is the code? A code for something doesn't necessarily mean that part is bad. It can mean it's simply not reading what's expected.




Exactly. Hence why I asked what else I can do to remedy this since replacing the sensor is not helping.

I do not have a code reader. I have taken it to two shops and Autozone to have it checked out and all have said the MAF sensor is not transmitting the proper reading and is causing the engine to run too lean.



 
454cid 
Valued Contributor
Posts: 3121

Age: 46
Loc: West Michigan
Reg: 02-18-12
03-02-19 10:39 AM - Post#2761119    
    In response to wreakhavoc

  • wreakhavoc Said:
  • 454cid Said:

What is the code? A code for something doesn't necessarily mean that part is bad. It can mean it's simply not reading what's expected.




Exactly. Hence why I asked what else I can do to remedy this since replacing the sensor is not helping.

I do not have a code reader. I have taken it to two shops and Autozone to have it checked out and all have said the MAF sensor is not transmitting the proper reading and is causing the engine to run too lean.



Get the codes pulled again, and ask for the specific codes.

99 K3500 RCLB


 
george88gta 
"15th Year" Silver Supporting Member
Posts: 1984
george88gta
Loc: new york
Reg: 04-23-03
03-02-19 11:22 AM - Post#2761120    
    In response to 454cid

Definitely write down the codes. In your first post you say it is running rich and then, later on, you say it is running lean. The codes will help with the exact failure mode. If it is really running lean, do a thorough inspection of the air intake system, after the MAF, and up to the intake manifold. If you are comfortable with spraying carb cleaner around the joints, the engine rpm will increase if you spray a spot that is leaking. BE VERY CAREFUL, don't drench the engine with fluid!!!!! Codes are still the best way to diagnose this.



 
wreakhavoc 
Poster
Posts: 64

Reg: 12-09-07
03-02-19 05:26 PM - Post#2761135    
    In response to george88gta

  • george88gta Said:
Definitely write down the codes. In your first post you say it is running rich and then, later on, you say it is running lean.


My mistake. I meant it was running too lean.




 
DenaliXL 
Contributor
Posts: 168

Reg: 02-25-07
03-07-19 02:31 PM - Post#2761545    
    In response to wreakhavoc

Perhaps the intake gaskets sucking unmetered air. Common with OEM gaskets.



 
elcamino 
Dedicated Member
Posts: 5411
elcamino
Loc: Lake Superior-Michigan US...
Reg: 03-30-00
03-07-19 03:24 PM - Post#2761553    
    In response to wreakhavoc

Are you using an oiled air filter?


  • Quote:
Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES)
Light On as a Result of the Installation of an Aftermarket Reusable, Excessively Oiled Air Filter

Models: 2004 and All Prior Cars and Light Duty Trucks
2003-2004 HUMMER H2

DO THIS
First, Inspect the vehicle for a reusable aftermarket excessively oiled air filter

DON'T DO THIS
DO NOT repair under warranty if concerns result from the use of a reusable aftermarket oiled air filter.

The installation of an aftermarket reusable, oiled air filter may result in:

1. Service Engine Soon (SES) Light On

2. Transmission shift concerns, slipping and damaged clutch(es) or band(s)

3. Engine driveability concerns, poor acceleration from a stop, limited engine RPM range.

The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur.

When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively oiled air filter. The MAF, GPS reading should be compared to a like vehicle with a OEM air box and filter under the same driving conditions to verify the concern.

Transmission or engine driveability concerns that are the result of the installation of an aftermarket reusable, excessively oiled air filter are not considered to be warrantable repair items.




Mike
2017 GMC Sierra Denali Ultimate 6.2L(420hp)/8-sp Z95
2018 Polaris RZR S 900 EPS


 
wreakhavoc 
Poster
Posts: 64

Reg: 12-09-07
05-29-19 07:46 AM - Post#2767279    
    In response to elcamino

Sorry, forgot to update...

It turned out to be a combination of three things- mass air flow sensor was indeed faulty transmitting incorrect information to the computer, bad fuel pressure regulator, and a rivet was missing on the underside of the throttle body. All of this was contributing to running too lean, lack of power, and check engine light constantly being on.

To boot, one screw holding the distributor cap on was loose, apparently had been stripped for awhile, and caused a spark to fly out and start a small fire when checking the fuel pressure. Luckily the only damage was a couple of melted vacuum lines and the plastic conduit on one wire harness. Turns out the OEM distributor was plastic (unbelievable) where the distributor cap screws on so the rim around the little screw hole was broken off. We of course replaced it with an aftermarket metal distributor.

After months of frustration with this all is well. No more check engine light on and is running great and with the boost in power that a 350 should have.



Edited by wreakhavoc on 05-29-19 07:48 AM. Reason for edit: No reason given.

 
rockfangd 
"6th Year" Gold Supporting Member
Posts: 2749
rockfangd
Age: 33
Loc: Utica ny
Reg: 04-13-10
05-30-19 06:56 PM - Post#2767375    
    In response to wreakhavoc

Cant stress enough why I never understood the plastic distributor.
Every astrovan I ever touched had a broken distributor. I never replace the screws when I replace the cap. I think the threadlock stays in the threads and is too much when the new screws are installed.


Old School GM fan FOREVER


 
wreakhavoc 
Poster
Posts: 64

Reg: 12-09-07
05-30-19 07:13 PM - Post#2767377    
    In response to rockfangd

Mine is Chevy Express 2500. My mechanic asked me if I had put in the new screws that came with the distributor cap. I didn't remember for certain but I said I probably would have.

When replacing a distributor cap in a van of course you're working from behind the engine so you can't really see what is going on with the front screw.



 
Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

409 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.08 seconds.   Total Queries: 16   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 03:51 PM
Top