Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hi Im David, are you getting rpms while cranking?
thats not good. and you cant communicate with the computer with a scan tool correct?
do you have a meter?
no reset button for the computer. that would be too easy.
i need you to check a few things with your meter at the DLC connector
where you plug the scan tool in
i need you to check for 12 volts dc at pin 16
check for a ground at pin 4
check for a ground at pin 5
check for 11.0 vdc at pin 7
what about the grounds for 4 and 5
you arent looking for power at 4 and 5 you looking for grounds. set the meter to ohms, and check the pins for ground.
put one meter lead on pin and the other to a nearby chassis ground
if its a good ground the meter will read 000
take a pic of how the meter is set up and attach it to here.
ok, then you definitely got issues with the wiring harness.
check all the fuses for the ecm/pcm/ecu/ dlc ill try to find a diagram
no rpms during crank =crank sensor/computer
no voltage from computer to dlc= wiring harness/computer.
when you turn the key to the run position(not start) can you hear the fuel pump run for a few seconds?
replaced what with a clutch?
ok now we need to check for spark
do you have a spark tester?
ok then lets check for spark. get back to me when you have the results.
ok. let check injector pulse. you have a noid light?
at the injector connectors
or if you dont have a noid light use a long plastic handled screw driver as a listening device. to hear each injector clicking.
ok. gotta walk the pooch check ya out in a few
when you crank the car does the security light go out?
ok. good. now when you turn the key to the run position(not start) does the check engine light come on?
all the light come on and most should go back out. does the check engine light stay on?
ok. well everything is working like it should. except it wont start and no power to dlc connector. check the cigarette lighter fuse or power outlet fuses. the dlc is tied into that circuit on a lot of vehicles.
should be 20 amp. was it labeled frt aux pwr oultet?
ok, well there is definitely a wiring issue or a pcm issue. i would be more comfortable if you could put a noid light on the injectors to see if the pcm is sending pulses to the injectors.
can you verify that you are getting fuel to the rail?
didnt you say the fuel pump is running?
but no pressure at rail?
check the filter.
or a kink in the lines somewhere.
how much gas is in the vehicle?
you need to hook up a gauge and check pressure at the rail. or if you think theres not enough pressure there by pressing in the schrader, then the only thing that can be wrong is the fuel pump.
where did you get the fuel pump from?
you;re going to have to get one. harbor freight sells them very cheap.
im not going to recommend replacing the pump until i know what the key on pressure is.
the ecm is doing everything its supposed to be doing, except supplying 12vdc to the DLC connector. if you dont have 50-60 psi at the rail while cranking the engine, the pump is shot.
ok. you might br able to get a loaner from autozone....and same to you.
no. that will mess up the computer. you need to trace the wire from 16 to the pcm and find out where the open is.
heres a pinout of the computer. its the same as the colbalt so dont worry
right here. ill keep it open
checking in to see how its going
give me a while to come up with a game plan.
no gauges are working?
im going to pull a print.
here....it looks like without that 16 volts to the dlc connector, your serial data line for the gauges aint happening.
if you are absolutely certian each fuse on these prints are good, then you need to find out why theres not 12vdc at 16 on the DLC
ok. youre welcome
just checking in to see how its going