help 88 s10 blazer rpms falling off when it wants to

i have checked fuel pressure,vaccum line,change ignition coil ,distibutor,wires, plugs,rotor distibutor cap,egr valve,egr seloniod,please help running out of money:banghead::banghead::banghead:

I'd say the best thing to do here would be to get it on a scanner and see what its dong. You could have a ECM problem, a lose/damaged wiring problem etc. You need to get it scanned and on a scanner and see what is happening.

i have a scanner just keeps giving me rich codes but dont really no what iam looking for besides what i read out of the haynes manual. is there a diffrent scanner that will tell u other stuff?

Do you have a scanner that can read real time data? If you do, watch what the 02 sensor is doing. Has the 02 sensor ever been replaced? Does the truck run alright for a couple of minutes when its cold, but shortly after that, power drops off?

yes it reaches temp and goes into closed loop it goes back and forth rich/ lean when it is acting up shows rich yes it seems like it does it when warmed up about mile from starting piont

yes the o2 been replaced sorry

If thats the case then I would be looking at two things. Assuming the related wiring is alright, and is not damaged, torn, or disprupted, I would be looking at a coolant temp sensor for the ECM or the ECM itself. What is the reading of the temp sensor on the ECM side? Is it within normal range? The emp sensor was very important in these systems and caused problems such as the one you are having.

i also replaced the temp sensor how do u tell if wiring is damaged i look at all of the and also how do u no when the ecm is bad it should give a code wright thanks

An ECM failure will not always give you a code. Sometimes they can work, but be failing and causing all types of driveability issues. This is an area I would be looking at closely. How is the voltage system on the truck? Is it charging prperly? Is it overcharging? Voltage fluctuations can cause issues. Checking your wiring to certain sensors is also a good idea. All you have to do is unplug the sensor, and probe it with a voltmeter.

how do u check the electronic spark control haynes manual says take to dealer i like to check that before i take to someone to check ecm