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View Full Version : 1979 Accord... rpm's drop at 55mph


equinelvr
Aug 23, 2004, 04:06 PM
What is happening is when I drive the car and I go to 55 or higher the rpms drop to 0 and then when the car slows down to 50 it comes back on. We changed the coil but that did not fix the problem. Does anyone have any ideas?

labman
Aug 23, 2004, 09:46 PM
We may have to work on this one for a while. I may not have the answer, but will do my best. Tell me a little more about the 79 Accord, computer, FI, type of fuel pump, etc. If you accelerate hard does it cut out at the same RPM in a lower gear?

equinelvr
Aug 24, 2004, 06:22 AM
It cuts out no matter what gear when you hit 55mph or higher and comes back on when you drop to 50. I don't think it has a computer or is fuel injected. It has an electronic fuel pump. It sputters when you accellerate hard, but we think that has to do with the carburator. We had been told that it could be the igniters or the pulse generator. We just picjed the car up so know nothing about the history.

labman
Aug 24, 2004, 08:22 AM
It could be that when you get enough torque on it, the engine is rocking in its mounts enough short out the ignition or fuel pump. Try revving the engine in gear with the brake on and see if it does it. You can have somebody else watch with the hood up for sparks or smoke.

I have a pair of wires with an LED and a 270 ohm resistor connecting them. I use it sometimes to try to find out what is happening. Connected into the ignition or fuel pump circuit, it tell you if you have power to that circuit when you have problems. You can drive with the LED sticking out the crack at the back of the hood. This can tell you if either the ignition or fuel pump is losing power when the engine cuts out. Start near the pump or coil. If the light goes out when the engine dies, move it back in the circuit until it doesn't. Then check everything between.

equinelvr
Aug 24, 2004, 08:33 AM
I will try those things. Thanks for the help.