Ford Ranger Forum - Forums for Ford Ranger enthusiasts!

Go Back   Ford Ranger Forum - Forums for Ford Ranger enthusiasts! > Engine Tech Forum > 4-Cylinder Tech
Forgot Password? Join Us!


Reply
 
LinkBack Thread Tools Search this Thread

  #1  
Old 08-29-2011, 11:20 PM
luv my broken Rangie :]
 
Join Date: Jul 2011
Posts: 109
Default Maf sensor.

Ok guys so I've been trying nd trying to fix my truck. It stalls out all the time it won't stay on more than 1 min at most. I've changed lots if things and havnt made any difference over $700. X.x now I'm suspecting it's my maf sensor, at first I ignored it because when I disconnect it my truck would die. It only starts with maf plugged in. A few days ago I decided to test it throughly by checking the signal voltage. I noticed that it varies each time it's turned on. with engine warm It's usually either at .7-.9v or other times around 1.2v it varies idk why. But usually when it starts stalling the signal voltage gets too low less than .7v after that it jumps up or down then the truck dies.

So my question is if anyone knows or can anyone tell me their signal voltage at idle?

When I rev up to 1500rpm voltage is around 1.2v
At 2500rpm it is around 1.6v

1990 Ford Ranger XLT 2.3L inline4
__________________
1990 ford ranger 2.3L
1999 Ford Ranger 2.5l

God bless!
Reply With Quote
  #2  
Old 08-30-2011, 12:26 PM
Junkyard Dog
 
Join Date: Sep 2010
Posts: 987
Default Re: Maf sensor.

Well this is not a graph of voltage to rpms but its to speed, but should give you a good idea. BTW this is from ALLDATA for your exact vehicle.

__________________
Quality Engineer (Electronics) for Kia Motors
University of Tennessee Electrical Engineering Graduate
2000 XLT 2.5L A/T
Mods:
Explorer OHC
Explorer Autodim Mirrors w/ Autolamps
Explorer Sport White Face Gauges
Reply With Quote
  #3  
Old 08-30-2011, 01:08 PM
Blinded by the light
 
Join Date: Sep 2009
Posts: 7,680
Send a message via AIM to FireRanger
Default Re: Maf sensor.

What have you done so far?
__________________
(Formerly)
FireRanger
2003 Edge 4.0 4wd

How to: Aux light wiring, relays, & fuses
Info: 300+ intake threads here on FRF
Info: HID Projectors
How To: NO HEAT Troubleshooting Guide
Reply With Quote
  #4  
Old 08-30-2011, 10:22 PM
luv my broken Rangie :]
 
Join Date: Jul 2011
Posts: 109
Default Re: Maf sensor.

What I've done to the truck is:

Replaced the fuel pump and fuel filter, replaced fuel pump relay, replaced tps sensor, replaced evp sensor, cleaned egr valve, changed vacuum hoses, cleaned and replaced iac valve and sensor with 2 different ones, replaced fuel pressure regulator, checked all fuses, changed crankshaft position sensor, checked timing belt, changed battery and cables, replaced Coolant temperature sensor, cleaned out the intake air temperature sensor, cleaned throttle body, cleaned maf sensor with special liquid, replaced throttlebody gasket, added Lucas injector cleaner, and lastly checked wiring and voltage.
__________________
1990 ford ranger 2.3L
1999 Ford Ranger 2.5l

God bless!
Reply With Quote
  #5  
Old 08-30-2011, 10:41 PM
luv my broken Rangie :]
 
Join Date: Jul 2011
Posts: 109
Talking Re: Maf sensor.

Quote:
Originally Posted by sheltonfilms View Post
Well this is not a graph of voltage to rpms but its to speed, but should give you a good idea. BTW this is from ALLDATA for your exact vehicle.

Wow looks like my idle at normal operating temperature is too high. Thx for this graph
__________________
1990 ford ranger 2.3L
1999 Ford Ranger 2.5l

God bless!
Reply With Quote
  #6  
Old 08-30-2011, 10:51 PM
Junkyard Dog
 
Join Date: Sep 2010
Posts: 987
Default Re: Maf sensor.

Compression test? How many miles?

It still may not be the MAF sensor. If it drops when its stalling it could just be the RPMS dropping causing the air volume to go down. So the voltage drop is the consequence of the engine stalling not the cause of the engine stalling.
__________________
Quality Engineer (Electronics) for Kia Motors
University of Tennessee Electrical Engineering Graduate
2000 XLT 2.5L A/T
Mods:
Explorer OHC
Explorer Autodim Mirrors w/ Autolamps
Explorer Sport White Face Gauges

Last edited by sheltonfilms; 08-30-2011 at 10:54 PM.
Reply With Quote
  #7  
Old 08-31-2011, 03:53 AM
Blinded by the light
 
Join Date: Sep 2009
Posts: 7,680
Send a message via AIM to FireRanger
Default Re: Maf sensor.

Plugs? Wires?
__________________
(Formerly)
FireRanger
2003 Edge 4.0 4wd

How to: Aux light wiring, relays, & fuses
Info: 300+ intake threads here on FRF
Info: HID Projectors
How To: NO HEAT Troubleshooting Guide
Reply With Quote
  #8  
Old 08-31-2011, 08:21 PM
luv my broken Rangie :]
 
Join Date: Jul 2011
Posts: 109
Default Re: Maf sensor.

Quote:
Originally Posted by FireRanger View Post
Plugs? Wires?
Woops forgot to add:

Changed all spark plugs and spark plug wires, replaced both ignition coils, and also replaced the ignition control module.
__________________
1990 ford ranger 2.3L
1999 Ford Ranger 2.5l

God bless!
Reply With Quote
  #9  
Old 08-31-2011, 08:24 PM
Blinded by the light
 
Join Date: Sep 2009
Posts: 7,680
Send a message via AIM to FireRanger
Default Re: Maf sensor.

hmm. Vacuum test? If you have a big vacuum leak somewhere, that could cause it too. Basically what we're getting at here is before you replace something expensive, rule out the cheap and free stuff. Like anthony said, the low reading could be simply because the RPM is dropping and the reading is correct.
__________________
(Formerly)
FireRanger
2003 Edge 4.0 4wd

How to: Aux light wiring, relays, & fuses
Info: 300+ intake threads here on FRF
Info: HID Projectors
How To: NO HEAT Troubleshooting Guide
Reply With Quote
  #10  
Old 08-31-2011, 08:34 PM
luv my broken Rangie :]
 
Join Date: Jul 2011
Posts: 109
Default Re: Maf sensor.

Quote:
Originally Posted by sheltonfilms View Post
Compression test? How many miles?

It still may not be the MAF sensor. If it drops when its stalling it could just be the RPMS dropping causing the air volume to go down. So the voltage drop is the consequence of the engine stalling not the cause of the engine stalling.
In my knowledge the Maf sensorl just sends information to the ECM or PCM it does not receive information from anything because it can't really control the amount of air going in so the signAl voltage drop shouldn't even b there when stalling I checked the 12v to it and it's always there even when stalling and that never changes. So I'm just saying that it shouldn't really b dropping cause of rpm, please correct me if I'm wrong. I understand what ur saying but the surging in voltage is a big difference for example from 1.2 to .6v nd back to 1.2v . What I think is happening is the Maf sensor is sending wrong info to the computer causing it to either inject more or less fuel. I also have a system lean code. Nd I replaced the o2 sensor as well and still get that code. I also checked for vacuum leaks.

----------

Quote:
Originally Posted by FireRanger View Post
hmm. Vacuum test? If you have a big vacuum leak somewhere, that could cause it too. Basically what we're getting at here is before you replace something expensive, rule out the cheap and free stuff. Like anthony said, the low reading could be simply because the RPM is dropping and the reading is correct.
Vacuum leaks was also one of the first things that I checked doesnt seem to b any. What else could cause this problem?
__________________
1990 ford ranger 2.3L
1999 Ford Ranger 2.5l

God bless!
Reply With Quote
  #11  
Old 08-31-2011, 08:34 PM
Junkyard Dog
 
Join Date: Sep 2010
Posts: 987
Default Re: Maf sensor.

What I meant was that when the engine stalls, the volume of air going into the engine decreases. This will cause less air to flow over the maf sensor, causing the REFERENCE voltage to drop.
__________________
Quality Engineer (Electronics) for Kia Motors
University of Tennessee Electrical Engineering Graduate
2000 XLT 2.5L A/T
Mods:
Explorer OHC
Explorer Autodim Mirrors w/ Autolamps
Explorer Sport White Face Gauges
Reply With Quote
  #12  
Old 08-31-2011, 08:36 PM
luv my broken Rangie :]
 
Join Date: Jul 2011
Posts: 109
Default Re: Maf sensor.

Quote:
Originally Posted by sheltonfilms View Post
What I meant was that when the engine stalls, the volume of air going into the engine decreases. This will cause less air to flow over the maf sensor, causing the REFERENCE voltage to drop.
Oh ok I understand now thanks for clearing it up what else do u think could cause this problem??
__________________
1990 ford ranger 2.3L
1999 Ford Ranger 2.5l

God bless!
Reply With Quote
  #13  
Old 08-31-2011, 08:39 PM
Blinded by the light
 
Join Date: Sep 2009
Posts: 7,680
Send a message via AIM to FireRanger
Default Re: Maf sensor.

I'm running out of things to test and replace here. You've practically replaced the entire engine. Alternator is working ok? 13.2-14 volts at idle?
__________________
(Formerly)
FireRanger
2003 Edge 4.0 4wd

How to: Aux light wiring, relays, & fuses
Info: 300+ intake threads here on FRF
Info: HID Projectors
How To: NO HEAT Troubleshooting Guide
Reply With Quote
  #14  
Old 08-31-2011, 08:40 PM
luv my broken Rangie :]
 
Join Date: Jul 2011
Posts: 109
Default Re: Maf sensor.

What causing a system lean code??
__________________
1990 ford ranger 2.3L
1999 Ford Ranger 2.5l

God bless!
Reply With Quote
  #15  
Old 08-31-2011, 08:56 PM
luv my broken Rangie :]
 
Join Date: Jul 2011
Posts: 109
Default Re: Maf sensor.

Quote:
Originally Posted by FireRanger View Post
I'm running out of things to test and replace here. You've practically replaced the entire engine. Alternator is working ok? 13.2-14 volts at idle?
Yea alternator is working properly good voltage, I'm thinking of doing the compression test maybe the problem is inside the engine x.x also another thing it's doing is that if u accelerate too fast or floor it either at idle or in gear it Boggs down instantly. I also thought it might b a clogged cat so I disconnected the exhaust line at the front before cat. Turns out not plugged...
__________________
1990 ford ranger 2.3L
1999 Ford Ranger 2.5l

God bless!
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
MAF sensor mod budgetliftedranger 3.0 Vulcan Tech 7 07-24-2011 05:27 PM
Maf sensor navseawelder1 General Ford Ranger Discussion 2 05-09-2011 02:51 PM
where is my MAF sensor ?????help!!! jackman General Tech 3 11-28-2010 09:47 PM
MAF sensor Cooter83 3.0 Vulcan Tech 16 11-25-2010 03:36 AM
MAF Sensor? 7339 4.0 SOHC / 4.0 OHV Tech 1 11-05-2009 07:13 PM



Search Engine Friendly URLs by vBSEO 3.6.0 ©2011, Crawlability, Inc.