Is it throwing any codes? I would start with checking the mass air sensor and throttle position sensor TPS.

Yeah this may be a tough fix. You will just have to track down all of the rat damage.

This....sorry but that kind of damage can take forever to find!! It is easier to find a complete replacement harness from a salvage yard and replace it.
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If vehicle will not let you pull codes with a reader try this....

This is an aid to the mechanic, is fast and does not need a diagnostic tool. The Nissan to bring the systems are the engines that bring FOLLOWING:
E16E engine (Nissan Sentra V-16 or red cap)
GA16DE, GA16DNE. (V-16 gray cover, almera, etc.).
SR20DE, SR20DET (Nissan Primera, Samsung SQ5, Almera)
KA24 (KA24: D21, D22 y Altima)
VQ30DE (Nissan Maxima, Pathfinder, x-trail, etc)

The proceeding is very simple:
1. Put the key in the ON position (check engine light comes on)
2. Jump pins 6 and 7 of the diagnostic connector 14-pin for two seconds until the check is turned off. After the check is turned off the light began to flash, giving us a code according to the time to blink. The tags will be repeated endlessly until you turn the key to the ON position to OFF for a while or until you clear the codes.

The long flashes represent the tens and short drives.
Example: 5 flashes long and five short shows code 55, which means that the whole system is in order.

To clear the stored fault codes at the time that show the possible failure code back to making the bridge for four or five seconds, the light should go out and check out the bridge is qeuda on, ready, it indicates that all codes are erased become the key to the OFF position and can you start the car.

THE LOCATION OF THE PINES GROWING VA LEFT TO RIGHT:
1----67 1 ---- 67
8-----14 8 ----- 14

It does sound electrical to me but could also be the EGR system, TPS, MAP, or other sensors, some will throw a code, some will not.

OK, this is a 94 so basically all the light throws a code for is the basic sensors, or smog system stuff. Its OBD 1 not OBD 2. I am sure the basic sensors have been covered and with the fuel smell coming from the carb it tells me there is unburned fuel. Look closely at all the repaired wires and also closely check all the wire terminals at the coil and every other ignition component. Had a ford do this for months, it got so bad it would be going down the road and just die, coast to the side of the road, turn key off and start it back up. Dealer spent over 1500.00 and did not fix it. I found a .16 Cent connector with only 2 wires connected to it. It was the coil resistance loop connector and it would build a static charge that would kill the coil, then when the motor died the charge would disapate and it would fire right back up. The kickdown harnes is a slim possibility, but it needs to be repaired to ensure the transmission does not get damaged. I am sure the TPS and speed sensors have been replaced, I still think there may be a missed wire that the rat/mouse bit into but did not chew through causing an intermittent and very hard to find problem.