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96, bad compressionleak down test

  • Thread starter Thread starter sg465
  • Start date Start date Dec 10, 2006
S

sg465

New Member
Apr 16, 2003
40
0
0
Dec 10, 2006
#1
  • Dec 10, 2006
  • #1
went to start my 96 Cobra for 1st time in a month. Fired right up and died. Tried starting again and nothing, starter started whining like an electric drill and car sounded like it slipped timing.
Fuel pressure is great, good spark and tried 3 different batteries.
Pulled starter out and found the bendix was staying in the engaged position.
Decided to check compression and it was low, around 60 psi, also found ALL cylinders soaked with fuel, all of them had fuel sitting on top of pistons.
Tried a leak down test but am confused with results. I even pull the drivers valve cover off to make sure that we had it on compression stroke. when I did it on 1, 2, 5 and 7 cylinders I get leaking out of intake manifold and different spark plug holes. I absolutely know when we tried teh leak down test on 1 and 2 we were on dead side of cam but they still leaked into the intake manifold.
Jump timing?? When I roll crank to timing mark the primary sprocket on cam is lined up where it should and is correct as far as i can tell to when the valves should be on #1.
So, will a bad starter crank slow and produce bad compression reults? why do all cylinders tested leak into intake manifold so bad??
 
B

bryanstang

New Member
May 29, 2005
6
0
0
Kissimmee, FL
Dec 25, 2006
#2
  • Dec 25, 2006
  • #2
Did you ever find out what the problem was with the car? I am having an identical problem. Car started then died and wont restart. I have spark, fuel pressure, ect. and all my plugs were soaked with fuel. I am curious to what your problem ended up being.
 

hotpony

Founding Member
Feb 26, 1999
922
12
38
Lee County, KY
Dec 26, 2006
#3
  • Dec 26, 2006
  • #3
Floor the gas pedal while cranking the engine until it fires up, this shuts off the fuel injectors.. Happens when you let em sit for a while..
 

cold96snake

20+ Year Stangneter
Jan 26, 2004
817
1
39
Truly, out to sea
Jan 2, 2007
#4
  • Jan 2, 2007
  • #4
hotpony said:
Floor the gas pedal while cranking the engine until it fires up, this shuts off the fuel injectors.. Happens when you let em sit for a while..
Click to expand...

werd, nothing like a carbed 302...the pcm is still re-calibrating a/f when you flooded it.
 

hotpony

Founding Member
Feb 26, 1999
922
12
38
Lee County, KY
Jan 2, 2007
#5
  • Jan 2, 2007
  • #5
It still recalibrates for a LEAN mixture when you have pure gasoline in the exhaust stream because the O2 sensors can't read pure fuel, flooring it acts as a choke for the PCM and does shut off fuel injectors. It's more so you don't flood the car while starting, but it's also a troubleshooting procedure.
 

cold96snake

20+ Year Stangneter
Jan 26, 2004
817
1
39
Truly, out to sea
Jan 2, 2007
#6
  • Jan 2, 2007
  • #6
hotpony said:
It still recalibrates for a LEAN mixture when you have pure gasoline in the exhaust stream because the O2 sensors can't read pure fuel, flooring it acts as a choke for the PCM and does shut off fuel injectors. It's more so you don't flood the car while starting, but it's also a troubleshooting procedure.
Click to expand...

actually replying to bryanstang, but yeah it works either way
 
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