Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: whitebeastxr7 on March 19, 2005, 07:10:19 PM

Title: will 5.0 start without o2 sensors hooked up?
Post by: whitebeastxr7 on March 19, 2005, 07:10:19 PM
I just finished up some of the last things on my 306 HO speed density transplant in my 1988 Cougar. I have been having some
problems with the Hpipe so I don't have the oxygen sensors hooked up but I wanted to strart it for a couple seconds. It won't start, so is the reason because of oxygen sensors or should it start and run open loop or something. It turns over and hear a pop every revolution.

One thing I do have is a kinked fuel return line, I thought maybe it would straighten itself out so this may be part of the reason it won't start. Also the distributor is from a 1993 Cobra, don't know if this makes a difference or not, maybe my mechanic has it off a tooth or 180 degrees off? I am just thinking of some of the possibilities, anybody could help, I'd appreciate it!
Title: Re: will 5.0 start without o2 sensors hooked up?
Post by: tbirdscott on March 19, 2005, 07:17:59 PM
It should run without them, really rich but it should fire and run.
Title: Re: will 5.0 start without o2 sensors hooked up?
Post by: shame302 on March 19, 2005, 07:41:38 PM
the o2s dont even come on untill oppr. temp or so i thought...

i was thinking maybe 180 off...?
Title: Re: will 5.0 start without o2 sensors hooked up?
Post by: V8Demon on March 19, 2005, 08:12:00 PM
It'll fire up....When I first put my headers on I drove my car 20 miles to my friends house to weld up a custom exhaust (he had a welder and was gonna come to me, but he could not).  Fired right up.
Title: Re: will 5.0 start without o2 sensors hooked up?
Post by: TurboCoupe50 on March 19, 2005, 08:30:38 PM
I't will start and run just fine.. Look up tables in the EEC will make it a bit rich, but not a big deal...

The o2 sensors start to operate as soon as they are hot and engine temp is more than stone cold.... By 100* or so they are sinding signals to the EEC and it is switched to closed loop...