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'89 C4 no start.

I love my Chevy Chevette!
Posts: 1
Joined: 04/13
Posted: 05/23/13 01:40 PM

My Vette took me to work, went to go to lunch and it would not crank-over. Short story version: By-Passed the Start-Delay Relay in dash center. Car now cranks over, however it will not start. Checked fuel pump has power, does not pump. Replaced pump, car started and I let it run for an hour. Next day it would not start, but did crank. Replace fuel pump relay next to wiper motor. Not starting, any advice. Thank You. 110k miles, automatic,Pressure washed engine bay prior, new cap & rotor, getting spark at plugs, will start on starting fluid, runs momentarily. Thank You, Oz  

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My first time was in a Chevy
Posts: 129
Joined: 03/13
Posted: 05/23/13 07:42 PM

i bet the security light is flashing..

you are more than likely having an issue with the VATS ignition lock cylinder.

i am hoping that you have a RADIO SHACK nearby...  oh yea... and this is totally reversible..

pick up a 15 turn 10K ohm trimmer pot..

Prs1c 2160217W345

10K-Ohm 15-Turn Cermet Potentiometer/Trimmer
Model: 271-343  | Catalog #: 271-343   $2.99

Prs1c 2266713W345

12-Position European-Style Mini Terminal Strip
Model: 274-680  | Catalog #: 274-680  $3.49
cut off 2 or 3 sections of this to hook direction to the pins on the pot..

you will need a digital ohm meter...
wire cutters.. and what ever it takes to remove the KNEE panel under the dash ..
a tiny screw driver.

you can if you also have a spare VATS ignition key. or have a NON vats ignition key that will operate the lock cylinder...

set the ohm meter to 20K ohms..  or 200K ohms..   measure the resistance of the key resistor pellet...

set the trimmer pot.. either the first and second wire or the second and third wire to the EXACT same setting..  

use the european style terminal blocks to connect to the pins.. then the pigtail you are about to cut off...

this is a VATS ignition switch for the 89 model C4 cars.. see the orange harness.. with the wire wires... it exists under the dash... comes out of the steering column beyond the bracket..


you will want to cut this 2 wire harness in a easy to get to location.. but please cut it on the ignition switch side of the black connector..
take the connector and what ever wire you cut out..  so the pigtail comes out in your hands..    i am trying to say.. DON"T CUT the harness on the dash board side of the black connector..

strip back the wires and use the european style terminal strip to attach to the first and second.. or the second and third wires coming out of the 10 turn trimmer pot..  which ever pair you adjusted to match the vats key resistor value..

now that you have installed the pigtail onto the trimmer.. plug it back in.. stick your key in the ignition and the car should start and run...

there is a 4 minute time out  if the resistance was wrong..


a different way around this situation..  you still have to pull the underdash panel and buy more stuff...

this involves additional trips around..

buy the lock cylinder shown above..  it comes with a NON VATS PLAIN KEY...

with your original VATS key in your pocket..  take the new lock to a key shop.. where they will OHM the resistor to select one of 15 possible blanks according to the resistance...

have them cut the new blank.. using the new NON VATS depths...

be sure to find out which of the 15 it is..

get under the dash.. find the orange harness..  unplug it...  plug the new lock cylinder orange harness connector in...   stick the new vats key into the new lock cylinder under the dash... yep..   tie wrap or electrical tape up the excess wiring length...  reinstall the knee panel.. and drive your car..  someday.. you will feel like spending the hour or three and tearing down the teloscopic column.  to install the new ignition lock cylinder thats been stashed under the dash.. being used just as a resistor..   you might want to leave the underdash lock cylinder turned to a position where the keys won't fall out.


lastly.. if you wanted to test the VATS harness and ignition switch..

get under the dash.. unplug the orange harness..  ohm the key.. note the value...

probe the end of the column side of the orange harness..  with the key out.. should be OPEN.. or OL..  with a key in and thru the on .. cranking and back to the ON position.. even perhaps in the OFF position.. you should have continuity of the same resistance from the resistor.. if it drops out.  it will lock you out of your driving the car for 4 minutes..

the reason i am not afraid to share this .. there are 15 keys of different resistor values..  there are significant numbers of different key combos..  and each different resistor value takes at least 4 minutes..  figure its going to take 8 to 10 tries to get to the proper value..   4 minutes.. x 8 = 32 or 40 minutes for 10 values..

i saw a posting online in the classified that all a lady wants is to get her car running for xmas..  the vats ignition was failing.. i put the 6 buck of parts in her car and she was so happy..  cost me about 10 in gasoline..  make somebodys day..  

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