[hrmwrm]

i have an 89 d100 with a 3.9L that won't run and am getting at my wits end.
it'll run as long as the key is turned to start, so injectors and ignition are fine as soon as you let go to run, it just dies.
as long as you keep pouring fuel to it, it'll stay running, so the injectors are turning off. i've jumpered the asd relay in case it was shutting down, but it still does the same thing.
it has a different throttle body due to a fuel leak, a different computer, and a new ignition switch.
still the same problem. just lost as to why it starts fine then dies unless the key is in start, or you keep pouring fuel to it.
so, spark is not a problem.

 

[68RT]

Check your ballast resistor.

 

[Bob Lincoln]

There is no ballast resistor used with vehicles that are computer-controlled and have fuel injection.

Check fault codes first: http://www.allpar.com/fix/codes/index.html

Did the trouble begin when you installed the different computer and ignition switch, or are they in response to a problem that began? Any other events when this problem began?

Is the different computer the same part number as original? If not, why not?

 

[valiant67]

There probably is not a ballast resitor on a 1989 truck. You probably need to concentrate on why the fuel shuts down which could be an ignition switch issue.

 

[hrmwrm]

There is no ballast resistor used with vehicles that are computer-controlled and have fuel injection.

Check fault codes first: http://www.allpar.com/fix/codes/index.html

Did the trouble begin when you installed the different computer and ignition switch, or are they in response to a problem that began? Any other events when this problem began?

Is the different computer the same part number as original? If not, why not?

computers have been switched back and forth from original to different.no change in symptoms. original problem was running poorly(rich).throttle body was changed which is where the problem seems to have started. it was used from a wreckers. yet the throttle body shoots fuel just fine in the start position. engine runs smooth as well. just don't pull too far back on the key. ignition switch was also replaced. but plugging in the old one produces the same results. i think i'm back into checking out the throttle bodies.
although i do wonder how it would work in start just fine yet stop when released to run.
oh, and there was a code 23, air temp too hot, or along those words on the scanner.

 

[hrmwrm]

back to original throttle body, and square one. runs, but rich on one side. guess the replacement is heading back to the wreckers.