Fuel and ecm
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
There is no VATS in '84. That started in 1986. You have TDS (Theft Deterrent System). The TDS also disables the starter, so what you did is valid.
The ECM needs to see pulses from the distributor before it will turn on the fuel pump. They come from the ignition module in the distributor. You could have a bad module, bad wiring, bad connector pin(s). You might have a bad pickup coil. It generates pulses as the distributor rotates that the ignition module amplifies and shapes into pulses the ECM can use.
Do you see any RPM displayed on your tach while cranking? If so, then the pickup coil and ignition module are OK.
The ECM needs to see pulses from the distributor before it will turn on the fuel pump. They come from the ignition module in the distributor. You could have a bad module, bad wiring, bad connector pin(s). You might have a bad pickup coil. It generates pulses as the distributor rotates that the ignition module amplifies and shapes into pulses the ECM can use.
Do you see any RPM displayed on your tach while cranking? If so, then the pickup coil and ignition module are OK.
Thread Starter
Heel & Toe
Joined: Dec 2011
Posts: 17
Likes: 0
From: nevada
Thread Starter
Heel & Toe
Joined: Dec 2011
Posts: 17
Likes: 0
From: nevada
Tried todat and no fuel again. Pump runs, no rpm on tach when cranking. I read where I could have burned out the prom on the ECM when I checked the fuel pump relay for power with a small test light. Installed a new fuel relay and coil. I don't have any access to info except you guys. Everybody here wants $100 per hr for checking system. Hope to solve this with yout help. It seems Im going one step forward and two steps back. Its a blessing that I have all day to fool with this as its my PROJECT! By I didn't intend it to be a career! Thanks again for taking the time to read this!
Thread Starter
Heel & Toe
Joined: Dec 2011
Posts: 17
Likes: 0
From: nevada
No fuel again today. No RPM showing on TACH when cranking. I read where I could have burned out the prom on the ECM when I was checking the FUEL PUMP RELAY, I replaced it and the coil. I can hear the pump running. What do you think?
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You can check for spark with a timing light, even if the engine is only cranking. That will tell you if the distributor is working OK.
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