MAF or Relays??
Thread Starter
Safety Car
Joined: Jul 2006
Posts: 3,696
Likes: 1
From: MA
MAF or Relays??
Hello Forum
If i try to start my Vette it will fire up then just die
If you start it up and try to keep it going by giving it gas.
It just pops (back fires) then it dies.
If i unplug the conector going to the MAF sensor it runs and doesnt die even when giving it gas
Im thinking it has something to do with MAF sensor or the 2 relays(power & hotwire heatup)
Has anyone ever had this problem??
And is this what a MAF sensor will do when it goes bad or the relays( good when unplugged)??
Here are the things ive done so far
Cleaned MAF sensor with electronics cleaner
Check all conector plugs to relays and MAF seem fine
Replaced air filter with K&N Prior to cleaning of MAF so OIL wouldnt be a issue
The car is a 1986
L98 350 TPI with 82000 Original on clock
Does anyone think im correct and the MAF is bad??
Thank you for any help
If i try to start my Vette it will fire up then just die
If you start it up and try to keep it going by giving it gas.
It just pops (back fires) then it dies.
If i unplug the conector going to the MAF sensor it runs and doesnt die even when giving it gas
Im thinking it has something to do with MAF sensor or the 2 relays(power & hotwire heatup)
Has anyone ever had this problem??
And is this what a MAF sensor will do when it goes bad or the relays( good when unplugged)??
Here are the things ive done so far
Cleaned MAF sensor with electronics cleaner
Check all conector plugs to relays and MAF seem fine
Replaced air filter with K&N Prior to cleaning of MAF so OIL wouldnt be a issue
The car is a 1986
L98 350 TPI with 82000 Original on clock
Does anyone think im correct and the MAF is bad??
Thank you for any help
Team Owner
Joined: Jan 2003
Posts: 20,322
Likes: 248
From: Summerland B.C. Canada
Does sound like a MAF problem. Is the SES light stuck on ?? Pulled the codes ??
Here is a little insight (86)
http://members.shaw.ca/corvette86/No...it%20Check.pdf
http://members.shaw.ca/corvette86/Code%2033.pdf
http://members.shaw.ca/corvette86/Code%2034.pdf
Here is a little insight (86)
http://members.shaw.ca/corvette86/No...it%20Check.pdf
http://members.shaw.ca/corvette86/Code%2033.pdf
http://members.shaw.ca/corvette86/Code%2034.pdf
Thread Starter
Safety Car
Joined: Jul 2006
Posts: 3,696
Likes: 1
From: MA
No codes
No check engine
The only time check engine come on is when i pull the conector off MAF
Then i come on about 10 second after running ( wich then seem to run ok when unplugged) so that leaning me toward a bad MAF sensor.
But there pricey .. And guessing not returnable
Just want to get some feed back making sure im correct and get other opinions as well
Where all here to help when our VETTES are feeling sick
Thank you
No check engine
The only time check engine come on is when i pull the conector off MAF
Then i come on about 10 second after running ( wich then seem to run ok when unplugged) so that leaning me toward a bad MAF sensor.
But there pricey .. And guessing not returnable
Just want to get some feed back making sure im correct and get other opinions as well
Where all here to help when our VETTES are feeling sick
Thank you
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Always replace the 2 relays behind the battery on the firewall first. See if that fixes the problem, as they are much cheaper than a new sensor.
Thread Starter
Safety Car
Joined: Jul 2006
Posts: 3,696
Likes: 1
From: MA
I just checked out the PDF that where sent in the last post that you refered to
Those pages are from the FSM i have
I notice one thing when i was reading and this make me believe it is for sure the MAF sensor
But the thing that confusing is i have no codes at all.
These page are for code 33 and 34 problems
But the one thing that is strange is this
Refering to code 34 test here what it says
A code 34 maybe caused by a engine that exhibits a low,rough, unstable or incorrect idle problem.Ifthis condiction exists,disconnect the MAF sensor. If the unstable idle exist, see Symptoms in section B. (rough, unstable,incorrect idle, or stalling) If idle improved with the sensor disconnected, replace it
And that exactly happens in my case
unplugged MAF and it runs fine but "check engine then pops on"
My question is now will a Bad MAF always throw a CODE or put check engine light on because in my case it didnt
Those pages are from the FSM i have
I notice one thing when i was reading and this make me believe it is for sure the MAF sensor
But the thing that confusing is i have no codes at all.
These page are for code 33 and 34 problems
But the one thing that is strange is this
Refering to code 34 test here what it says
A code 34 maybe caused by a engine that exhibits a low,rough, unstable or incorrect idle problem.Ifthis condiction exists,disconnect the MAF sensor. If the unstable idle exist, see Symptoms in section B. (rough, unstable,incorrect idle, or stalling) If idle improved with the sensor disconnected, replace it
And that exactly happens in my case
unplugged MAF and it runs fine but "check engine then pops on"
My question is now will a Bad MAF always throw a CODE or put check engine light on because in my case it didnt
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Most often it will throw a code (bad MAF or MAF relays) but it seems like you've hit the nail on the head. Do as others suggested and replace BOTH relays first, comparatively they're cheap versus a new MAF.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by Repzard
My question is now will a Bad MAF always throw a CODE or put check engine light on because in my case it didnt
RACE ON!!!
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Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by CFI-EFI
Otherwise, an approach like, "Always replace the 2 relays behind the battery on the firewall first.", is nothing but blindly throwing money at the problem. Relays and most other components, can be individually tested.
RACE ON!!!
RACE ON!!!
Originally Posted by RRT C4 General
It is known for sensors to go out and not throw a code.
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
It is strongly suggested that whenever the MAF itself is replaced, the relays themselves should be replaced also, good or bad, as they can cause a new MAF to fail prematurely.
Thread Starter
Safety Car
Joined: Jul 2006
Posts: 3,696
Likes: 1
From: MA
I summited a update on the other post
The problem i was having was a bad MAF sensor(with no codes)
But like Vader said
I also replace the 2 relays to be safe
Thank you forum for your help
Couldnt do it without you guys
The problem i was having was a bad MAF sensor(with no codes)
But like Vader said
I also replace the 2 relays to be safe
Thank you forum for your help
Couldnt do it without you guys
