Need some help with this one. I have a 1990 Chev Lumina with a 3.1L engine.
Was a complete no start and I determined that the Crank position sensor was
bad. Replaced it and it started up. test drove it down the street and it
died on me. When I went to start it up it would start up but as soon as I
released the key back into the run position it dies. No codes present. I
ran the fuel pump manually and still got the same results. It appears to me
that something is shutting off the injectors and the spark is okay.
Any hlep would be appreciated.
Mine is the same way, except that we noted that it stalled intermitently. We have cleaned the injectors, changed the fuel filter, r/r fuel pump and added a prong that Chevrolet indicated - still it happens. Since it is intermitent no codes are present. It appears that the fuel supply is being stopped or overloaded when this happens. Let me know what you learn. . .
When your vehicle first starts it's using factory preset readings to enable
it to start without the engine turning over an over until sensor readings
get to normal. When the computer stops giving these readings something is
then telling your vehicle the wrong thing. First off you'll need to track
down an area to start looking in, example being if it were backfiring, or
deiseling you would look towards a timing issue. Seeing as how you have
been focused on the fuel system, I would assume your running out of gas, so
something is telling your fuel system to trim the fuel. I've seen this same
problem once before on a chevy, this is no gaurantee but, disconect your
mass air flow sensor and see if that fixes it.
The reason your not getting a code is because your sensors are in fact working, the problem is they are sending the wrong readings. This makes the diagnosis very difficult. One method of finding it (doesn't always work) is to disconnect various sensors ( forcing the computer to give a preset reading) until you find the one causing the problem.