intermittent start problem, please help!

[sholady]

Our car is a 92 Taurus SHO. Heres the deal. Recently started running rough at idle and when given gas acted if it was flooded, but then cleared. Pull codes and one of the codes that I can specifically remember is BAP sensor. ECU obviously goes into default and temporarily clears problem, because check engine light was still on but the stumble was gone. Next my wife complains that car would spin but won't start.(This is her handle by the way)I go to check it and vroom! Fires right up! So we are lost. Drove it to work last night and let her drive my truck. Try to crank it when I got off and it just spun over. Fuel pump is working. There is fuel at the rails, but I am not sure if injectors are pulsing or not.Have another guy spin it over so I could check spark. There was no spark! WTF! Don't forget, this problem is intermittent. It may crank this evening when I get back to work. What is going on with this car? Can the BAP sensor cause these problems or is it something like a crank or camshaft sensor? Your help is appreciated. Sorry so long, but I wanted to explain it best as possible. If it helps any, tach is at about 500-700 rpm when cranking.

 

[sholady]

Bump! Seriously need some help here guys.

 

[93EmeraldMTX]

lol, when i put the SHO back togethor after i did valve cover gaskets, i had no spark, and for a couple days couldnt figure out why. all of a sudden, on the 3rd day, i go out to try to work on it again, and it fires right up. god knows why, but I havnt had problums since.


DERRR... i dunno why i posted that, it doesnt help you any.

 

[sholady]

Car has me over a barrel and it is still sitting at my job. Wish someone knew what could cause it. Its embarassing trying to start a car that just sits a spins. Some ideas! Anybody.

 

[projectSHO89]

I guess "spins" means that it "cranks, but does not fire".

Sounds very much like a CPS failure.

I posted awhile back on how to test the sensor without removing it first. Dig up that post and take a meter back out there or...

A suggestion: Tow it home. It's probably going to be awhile.

Steve

 

[sholady]

Well, if the tach works will cranking doesn't that eliminate the cps? I get 500rpm on the tach when cranking. Can the cam sensor do it? What does that BAP do? Can it be the problem? I got a code on it in the past. Will pull codes sometime after I get off.

 

[rangerj]

SHOLADY,

You say "one of the codes you remember is the BAP......". What are all of the codes you got when you checked them. BUMP!

An easy way to tell if the injectors are opening and closing is to listen with a mechanics stethescope placed against the body of the injector.

You could also place the tip of a screwdriver against the injector with the other end to your ear, and listen to the clicking sound the injector makes as it opens and closes.

It may help to check all of the connections for clean, corrosion free contact, including the grounds. The fact that the problem is intermittent hints at a connection problem.

Pull the codes again, both KOEO and KOER, and get back to us. rangerj

 

[93EmeraldMTX]

rangerj:
SHOLADY,

You say "one of the codes you remember is the BAP......". What are all of the codes you got when you checked them. BUMP!

An easy way to tell if the injectors are opening and closing is to listen with a mechanics stethescope placed against the body of the injector.

You could also place the tip of a screwdriver against the injector with the other end to your ear, and listen to the clicking sound the injector makes as it opens and closes.

It may help to check all of the connections for clean, corrosion free contact, including the grounds. The fact that the problem is intermittent hints at a connection problem.

Pull the codes again, both KOEO and KOER, and get back to us. rangerj

the thing is it needs to run when he does that, but it isnt firing.

 

[sholady]

Pulled codes this morning. I got 116 and 126. Coolant temp sensor and BAP sensor. Now I need to know can this cause it not to start?

 

[projectSHO89]

Those codes are extremely unlikely to cause a "Cranks, but does not fire" symptom.

In what section of the test were the codes issued, the KOEO or the Continuous Memeory section?

If there is no spark and you are confident of that, focus troubleshooting on the coil and it's power connection, the DIS module to coil harness, and the inputs to the DIS module. Also, verify proper grounding for the DIS module via the intake manifold and grounding strap.

You will need a voltmeter for any tests. Radio Shack or Sears for about $20.

This thread, http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=004200#000004 will help you perform static tests of the coil. It also will orient you to the pin/terminal locations on it.

This thread, http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=004988#000003 gives dynamic test procedures along with other member's experiences.

Also, observe and report what the CEL does while cranking. Does it stay on or does it go out while cranking?

Good luck.

Steve

<small>[ March 09, 2003, 09:24 AM: Message edited by: projectSHO89 ]</small>