Maf Sensor Help
Thread Starter
Melting Slicks
Joined: Aug 1999
Posts: 2,619
Likes: 1
From: Whidbey Island Washington
Maf Sensor Help
Got my '89 L98 tuned today: plugs, wires, ditributor, relays etc. Starts, idles, and runs much better, BUT only with gentle throttle pedal pressure. Hard or full throttle pressure and it goes flat with no acceleration. Gentle throttle pressure and it easily cruised at 60 mph...maybe could have gone faster but any slight hill and it had a heck of a time making the grade.
Mechanic ran several tests on MAF sensor and looked for codes. None found. No screen in MAF or cats on car.
Mechanic said I need to replace MAF...~$250 + installation. OUCH!Where can I buy one for less? How about a used one from a low mileage '89?
Can I install it myself...degree of difficulty? Before we had computers etc I could do a tune up myself (1950 vintage V8s).
Thanks in advance for the help.
Mechanic ran several tests on MAF sensor and looked for codes. None found. No screen in MAF or cats on car.
Mechanic said I need to replace MAF...~$250 + installation. OUCH!Where can I buy one for less? How about a used one from a low mileage '89?
Can I install it myself...degree of difficulty? Before we had computers etc I could do a tune up myself (1950 vintage V8s).
Thanks in advance for the help.
Team Owner
Joined: Sep 2001
Posts: 62,126
Likes: 1,727
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
MAF will give some kind of code fault when its bad. If you dont have Code 33,34,36 or whatever, then theres something else wrong.
Did you consider a fuel pump or supply issue yet?
Did you consider a fuel pump or supply issue yet?
Burning Brakes
Joined: Jun 2005
Posts: 802
Likes: 0
From: What do I know anyway? I'm just a 50 year old No0b
I went through a similar problem just a couple of weeks ago with my '89. Fuel pressure was good and no cats either. I unhooked the cable from the maf and the car ran just as good with it unconnected as with it hooked up. A new rebuilt BOSCH unit and things are back to normal. I got mine from Advance Auto for around $180. Replace both maf relays while you are at it, they are cheap insurance for the new maf. It's really easy to do, no special tools and only takes a few minutes. 
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by Dynabob
I went through a similar problem just a couple of weeks ago with my '89. Fuel pressure was good and no cats either. I unhooked the cable from the maf and the car ran just as good with it unconnected as with it hooked up. A new rebuilt BOSCH unit and things are back to normal. I got mine from Advance Auto for around $180. Replace both maf relays while you are at it, they are cheap insurance for the new maf. It's really easy to do, no special tools and only takes a few minutes.
Drifting
Joined: Apr 1999
Posts: 1,261
Likes: 6
From: Middletown New Jersey
You might want to check your TPS with a voltmeter or a scanner. You shouldn't have to press the pedal on starting generally and it might be falling on its face in the upper rpm ranges if the tps is sending a bad signal. The range should be from about .54 volts to over 4 volts. The important thing is to make sure the transition from no throttle to high throttle is linear.
