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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Can anyone help me out. Not sure whats going on

  • Thread starter Thread starter joeg500
  • Start date Start date Sep 17, 2007

joeg500

New Member
Sep 14, 2007
25
0
0
Sep 17, 2007
#1
  • Sep 17, 2007
  • #1
I have a big problem. Over the winter/spring I took my motor out and cleaned everything up and hooked on a new five speed. Well when I got the mods on and put it back in it is doing this weird start and stall thing. When I crank it over it will start and idle real quick for about a second and then it dies. I checked all the connections and they are all good. The only thing I noticed was that I only have one oxygen sensor. Does anybody know if only having one will cause that? I am getting the other one but I just want to know if I can look forward to it running with that or what else needs done.
 

87foxstang

Member
May 10, 2007
0
0
16
Cromwell, CT
Sep 17, 2007
#2
  • Sep 17, 2007
  • #2
yea, you should definitely have two oxygen sensors, only running one on a setup that should have 2 will cause the computer to run in a open loop form, meaning its sensing theres something wrong, so it is goning to run all erratic and stall...
This happened to me, well similar anyways, but hook up that second sensor and hopefully that will fix it

good luck
 

ninety15.0

New Member
Mar 10, 2004
1,336
0
0
Sep 17, 2007
#3
  • Sep 17, 2007
  • #3
When the computer is in open loop it falls back on pre-programmed timing and fuel curves and doesnt do any adaptive learning. It does not use any information from the O2's.

Now i dont know if only having one O2 will definitely make the comp run in OL...but it most likely will. It should also kick out a Check Engine light right now? Do you have a CE light on the dash when it does start?

What happens when you keep your foot on the gas when it starts? will it keep running? How much of the motor did you disassemble?

Have you checked all the basics? Distributor timing, Firing order, plugs, wires,cap, rotor, fuel filter?

Be a little more specific and we can probably get this ****** running?
 

PUNISHER RACING

Active Member
Aug 27, 2007
1,124
0
36
FORD CITY, PA.
Sep 17, 2007
#4
  • Sep 17, 2007
  • #4
Listen to your fuel pump while its running it sounds like your relay is bad it will click over to prime and will not jump back over to run position. You will only burn the fuel that was primed and then it shuts off. Had this happen , my 2 cents.
 

joeg500

New Member
Sep 14, 2007
25
0
0
Sep 18, 2007
#5
  • Sep 18, 2007
  • #5
The fuel pump runs. I can hear it when i turn the key on and i have double checked all the basics. When i hold it to the floor it just revs louder for that sec and then dies or once and a while it will last about two or three secs haha. I only took the heads off and put new gaskets on and took the intake off and cleaned it up and put new gaskets on. Nothing out of the ordianry like taking out the crank and stuff like that.
 

SVT32VDOHC

waiting for the next hack atta
Founding Member
Nov 22, 2001
3,501
28
119
Motor City
Sep 18, 2007
#6
  • Sep 18, 2007
  • #6
That is gotta be it. My car wouldn't run at all like that.
 

joeg500

New Member
Sep 14, 2007
25
0
0
Sep 18, 2007
#7
  • Sep 18, 2007
  • #7
Ok thanks ill try it out and let you guys know what happens
 

joeg500

New Member
Sep 14, 2007
25
0
0
Oct 1, 2007
#8
  • Oct 1, 2007
  • #8
Well i tried the oxygen sensor and still almost the same thing. It runs for about 3 seconds now. Where is the fuel pump relay located? I will check that out to see if that could be going wrong like Punisher Racing said. It will run a little bit better if I keep it alive by holding the pedal down. Im still stumped. Could there be something messing with the idel??
 
F

Fox8950

Member
Jun 29, 2007
247
2
18
Oct 1, 2007
#9
  • Oct 1, 2007
  • #9
If you have 2 relays on the fenderwall under the MAF then its one of those but if there is only 1 relay there its under the driver side seat. What year ya driving?
 

joeg500

New Member
Sep 14, 2007
25
0
0
Oct 1, 2007
#10
  • Oct 1, 2007
  • #10
i found the one under the seat. i forget how to check to see if they are good.
 
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