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Topic: will 5.0 start without o2 sensors hooked up? (Read 884 times) previous topic - next topic

will 5.0 start without o2 sensors hooked up?

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!

Re: will 5.0 start without o2 sensors hooked up?

Reply #1
It should run without them, really rich but it should fire and run.
1980 birds X 3, 1982 bird, 1984 XR7, 1988 TC

Re: will 5.0 start without o2 sensors hooked up?

Reply #2
the o2s dont even come on untill oppr. temp or so i thought...

i was thinking maybe 180 off...?
:america: 1988 Thunderbird Sport, Former 4.6 DOHC T56 conversion project.

Rest of the country, Welcome to Massachusettes. Enjoy your stay.

 
Halfbreed... Mango Orange Y2K Mustang GT
FRPP complete 2000 Cobra engine swap, T56 n' junk...
~John~

Re: will 5.0 start without o2 sensors hooked up?

Reply #3
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.
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

Re: will 5.0 start without o2 sensors hooked up?

Reply #4
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...