Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.
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Monday, February 15th, 2010 AT 7:25 PM
ASCLARCH
MEMBER
3 POSTS
1993 CHEVROLET SUBURBAN
V8
4WD
AUTOMATIC
200,000 MILES
I was driving and the suburban quit at a stop.I found the 25 amp fuel pump fuse blown replaced it. Tried to start nothing. I looked for other fuses and found the ECM 10 amp fuse blown also. I replaced this too. It started right up. Go to shut it off after it runs for 10 minutes and it won't shut off with the key. I tried 3-4 times and finally pulled the ECM fuse. I tested 3 times and does the same thing. I unhooked the battery to reset and same thing. If I pull the ECM or INJ A/B fuse it will die but the key does nothing. The switch seems to work the radio and tach (aftermarket hooked to distributor and fuse box) shut off with the key. The guages stay on when key is in off engine running. I pulled the ignition module out from under the dash and could start it but not shut it off with it. While it was running I pulled the wire plugs out of the module and it countinued to run. It should have stopped with the wires unhooked I believe?
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Friday, February 8th, 2019 AT 6:01 PM
(Merged)
JDL
MECHANIC
16,098 POSTS
Welcome to the forum, were you having a problem before you installed the tach? Key off, there shouldn't be any primary voltage at the coil. Is there?
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Friday, February 8th, 2019 AT 6:01 PM
(Merged)
ASCLARCH
MEMBER
3 POSTS
Thanks, The tach was installed 2 years ago. Never had this problem before Friday. I checked the voltage at the coil with the key off is 0v With the key on there is 12v.
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Friday, February 8th, 2019 AT 6:01 PM
(Merged)
JDL
MECHANIC
16,098 POSTS
Key off, engine running, there is no voltage at the coil? If that is the case, maybe detonation, if no spark something has to ignite the fuel mixture? Is the timing ok?
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Friday, February 8th, 2019 AT 6:01 PM
(Merged)
ASCLARCH
MEMBER
3 POSTS
Yep timing is fine everything works. Just the key doesn't shut it off now. It is not dieseling.