89 starts once a day

:confused:

have been working on an 89 Park Avenue Electra 186,000 miles
Will usually only start once a day and run for any where from 2 seconds to several minutes. Have replaced in tank fuel pump, crank sensor, cam sensor, ignition control module, camshaft gear and magnet, timing chain, crankshaft gear, oil pressure sending unit.
When it quits the fuel injection signal quits, still have spark signal, fuel pressure on the rail. Will run with starting fluid.
At wits end, what controls the fuel injector signal, I thought it was the cam sensor after the warm up period? Looking at replacing the computer but not sure what to do next.
pulling my hair out, anybody
edthead

Had same problems with '92 Park Ave., five yrs ago.
After 5 months, all new parts and computer, found that the culprit
to the problems you are describing to be the 'throttle body' censor.
All has been perfect ever since!
Wonder if yours could be the same thing?
Hope this helps.

The cam sensor gives the PCM timing information needed to fire the injectors. Injector pluse is controlled by the PCM. You have replaced everything else, and if installed correctly, it should work unless the PCM is fried. I would check all the connectors and grounds, then if it won’t run, install the brain.

In making the statement above, I assumed from your post, that the injectors are not plusing. How did you check that?

After it would quit running I disconnected the lead to one of the fuel injectors and installed a NOID test light (autozone $7) and it didn't flash, I also have an old inline timing light that doesn't use a trigger, so it will flash all the time, I hooked it up to a spark plug and place the timing light under the wiper arm so I can see it from the drivers seat and tell if I'm getting spark. Anyway, I get a NOID signal at initial start up but not after it quits. Oh, I also have placed a fuel gage on the rail and leave it hooked up, I get a steady 40psi when I turn the key on and after the engine starts it shows a constant 35psi there. This car seems to run longer if I increase the RPM and hold it there but if I bring it back near idle it will just shut off.
Wondering out loud, The car has set so long the axle seals have leaked alot of tranny fluid on the ground, is there any kind of sensor or switch that will shut the engine down to protect it if the computer senses something that will harm the powertrain?
ed

"Wondering out loud, The car has set so long the axle seals have leaked alot of tranny fluid on the ground, is there any kind of sensor or switch that will shut the engine down to protect it if the computer senses something that will harm the powertrain?"

So far you have used all the correct troubleshooting techniques, much better than most people! Sorry, there is no such sensor as described above. Again, the PCM controls the injector pulse based on correct timing input from the cam sensor.

Some good info on cam & crank sensors and how they control the injector pulse.

http://www.automotiveforums.com/vbulletin/showthread.php?t=182197&highlight=water+pump
Code41camsensor&magnet

Well, it's 92 outside and I got home from work, thought I'd go out and start the car. Cranks but no start. Hasn't done that in a while. Got fuel at rail and spark, shot some starting fuel into it. It tried to fireup. What would be so heat sensitive that it would not allow it to start on a hot day. I have voltage to one side of the injectors which stays hot when the key is in the on/run position. This means that the ground is controled thru the computer behind the glove box, sorry for all you purest, so pissed at this car can't think of the correct name, The troubleshooting chart says "if no injector signal,test light flashes: check for ground/shorted wire or repair injector control unit which is inside computer behind glove box.
any thoughts

ECM, PCM or "the brain" is the common terms used to describe the computer. Also, when they don't work, we refer to it as a "brain fart".

went to the junk yard and bought a used ecm, got ripped I guess, paid 75 dollars. Autozone sells one reman for 78 dollars. Anyway, this one plugged right in and vehicle starts every time now. Will test for next several days to make sure it keeps starting before I return to owner.
Learned alot about 3.8's and their workings.
Before throwing parts at your car, here is a list of things that I have done.
Replaced crankshaft sensor, car started but died after short period
Replaced camshaft sensor, car started but died after short period
Replaced ignition control module and coil pack, car started and seemed to run longer but still died.
Replaced engine oil pressure switch, thinking bad oil pressure and computer would shut off fuel to save motor, car started and died after short period
Heard about flaky magnet on camshaft gear, pulled front engine cover and replaced timing gear set and the magnet was oil soaked and crumbled when I touched it, car started and died after short period
Knew that I had spark but when car quit running was loosing injector signal.
Read about ECM computes injector pulse signal.
Replace ECM, engine starts every time and runs until shut off, engine not perfectly smooth but keeps running.
Hope this helps anyone with same problem.
ICM controls spark
ECM controls fuel injectors
ed