my 2000 did something similar i don't remember if the tach twitched but the signals and gauges did and the engine would quit. i tried testing everything and it ended up the battery was i was told "internally shorted" had never heard of this before. 2 ac delco batteries did this the original and the first replacement about a year later. if you have a spare it might be worth a try.

 

unfortunatly thats not my case, i HAD a bad battery, you know the ones that only would stay charged enough to start for a day, if you went a day without starting the truck it died, then i had a "temperary" battery untill i put an optima red top in it, sorry i failed to mention the battery being replaced earlyer in this post, thanks though, i have a list of sensors i MAY replaced before i lose hope as a gamble, seeing its ganna cost a few hundred to get my jeep set up, but its a rugged ride, no ac, no radio, non working gas gauge, 5.9L 360 3 spped auto trans, loves gas lol, but as for the blazer thinking maybe ECU, TPS,Camshaft+Crankshaft sensor, MAP, Purge solenoid, all shots in the dark i presume, and i plan on getting a tester and checking the grounds, seems it mostly wanted to act up in bad weather, lol it likes to run decent on sunny days i've realized, just dont know if i can continue to take "shots in the dark" or get the jeep to "good enough" it needs the window tracks fixed, to pass inspection, and a battery, and god knows possibly tires i dont know yet

ok so ive been doing some research today, yesterday when my blazer messed up and cost me my job interview, the only code i got was for an o2 sensor, to rich, any insight into what could cause my engine to run to rish?? bad tps? bad map?

 

well the shop said it could be like 9 different things but they couldnt isolate it, does anyone thing any of the follow things i found upon doing resarch think it could be it, i'm leaning with an electrical issue as the spider and nut kit are brand new, new cap and rotor, and the fuel filter is brand new(and others, to those who havent read this yet all replaced parts are on the 1st post, EXCEPT the battery, it is mention later) well im leaning with an electrical issue because it seems more prone to acting up in "damp" conditions
TPS,MAP,ECU/PCM,Purge Solenoid(sometimes it clicks while running others it doesnt)Coolant Temp Sensor?,(really want some good insight before replacing, im laid off and funds are VERY tight at the moment)

 

i had a similar issue with my Jimmy. idle up n down and "bucking". codes that i got were for the TPS, which is roughly $30 and "random multiple cylinder misfire". after changing the TPS and the coil wire, which rubbed through and was grounding on the tranny dipstick tube, the check engine light would occasionally still come on. i had it checked again and the electrical side of the EGR valve was faulting out. i changed it and didn't have the sporadic idle again. just other issues with the cooling system that im dealing with.lol. hope this helps out

 

You should check your fuel pressure to make sure it is at 58-60psi..... just cause you have a new FPR and spider doesnt mean its not defective or intermetly defective....and you could have a leaky pulsator at the tank....this is just some basic checks....

 

thanks guys, ill be checking out these issues, as far as the fuel pressure issue, i was told my fuel pressue is fine and they did check the inside the intake manifold again and said everything seems to be working fine in the spide department, with the new spider and nut kit i did notice that everything seems smoother and ran smoother and was more throttle responsive, that the old spider may have had a small internal leak or clog, that there wasnt much pooling or anything, that they think its an electrical issue some where seeing that its humid weather prone, ill be replacing the TPS and seeing if that helps, maybe the TPS is going bad in the form of the TPS telling the ECM to put more gas in than actually needed and it doesnt realize it untill the o2 sensor picks it up, which this could explain why my o2 sensor said i was running rich, or maybe the ecm is going out, the truck is 16 years old with 166,500 miles, i was also told that there could be nothing wrong and it is the ECM thinking theres a problem and trying to correct something thats really not there, i found a new ECM from advance autoparts for 56 dollars and its not hard to replace at all, but if i replaced the ECM would the truck run or would it have to take it to GM and get it reprogrammed?

 

ok well after replacing the injectors and a million other parts and with no visible vacuum leaks, someone suggested i try using a multimeter to test my sensors, well tested my sensors got to the Canister Purge Solenoid Valve , well my haynes repair book said to test that unplug the sensor and test the connecter with key ON engine OFF and i should read battery voltage to the connecter, well, i got nothing, like 0.01, cut the engine on and its jumping from 13.98 to 8 to 11 to 7 to 13.80 and all over the place and wont settle down, no trouble codes for anything however, only 1 i had was it was running rich 1 day when it was stalling and surging and only acts up in the rain 9/10 times or any humidity, anyway, anyone know what i do from here? i did replace the solenoid but where do it go from here? thanks for everyone who helped me!

 

anything?

 

Impatient much? Seems this is related to another thread of yours and by posting in a new thread, you have forced others to search, then read through what you may have already done... Best to keep your problems in one place which is why I have merged your threads back together.

As far as the purge solenoid is concerned, it should have +12V ignition switched power on the pink wire and the ground side (green/white wire) is switched by the PCM.

 

right but im not reading any voltage to that, and i have read that EVAP problems can cause my issues, anyway being that im not getting any voltage to it untill the truck is on and running could this be a self fixable issue or do i have to take it to a dealership and could this be a PCM problem? does this problem make sense to anyone that it is really prone to humidity? and seems to act "ok" on sunny days