I need some ideas on what the problem could be..I had the problem before but put some stp water evaporator in the gas tank and it seemed to fix it. Then this morning I drove it for 10 minutes and it started messing up again, the gauges went crazy then the idle went crazy. I think something is getting wet because when the motors is off and just the power is on, the rpm gauge jumps up to 100 Rpms and back down by its self ...I need some help or ideas from somebody??? Thanks

 

A good place to look and check would be where the plug attaches to the ECM. Water/moisture there can cause MULTIPLE problems such as you are getting.
If all is clean and show no water /moisture presence, check the ignition system plugs and connectors because they affect IGN and RPM signals.

 

Alright thanks..I also turned the power on without starting it yesterday morning and the fuel pump didn't send so I left it off for the day and turned it on lastnight and the fuel pump sent and i ran it about 6 miles without a problem, Idk why it happened to work then but it seems to be running decent now.. Appreciate the help man. I'll get back on if I have anymore trouble

 

There should be two relays that operate when you turn the key on. One would be the EEC power relay and the other should be the Fuel Pump relay. The EEC relay stays picked and the fuel pump relay oprates for 2 seconds unless you are cranking the engine at which time the EEC gets an RPM signal and that allows the EEC (computer) to keep the fuel pump solenoid activated. Might be a good idea to check the connections to those relays.