My blazers been in and out of the shop for a long time now, nobody can fix it completely. The current problem: in idle, the rpms will get really high and then get really low but it wont die or get close. Put it in gear and sometimes the rpms get high and it will accelerate to about 15mph without even pressing the gas pedal. When driving the rpms do the same thing, but quicker. For instance, the rpms will be where they should be around 60mph then theyll randomly jump up and then drop back to where they should be.

Here's all thats been done to it within the last few months...
New: map sensor, throttle positioning sensor, cap, rotor, injector, idle air control, (thing that sends the water/coolant temp?), fuel filter, fuel pump, fuel switch relay, the engine control module thing, transmission service...i THINK that's all...oh, also, it wasnt throwin any codes last time in the shop.

If you have any suggestions or ideas, PLEASE take the time to comment, this is killin my wallet and i dont have time or money to keep takin it to a shop.

 

Where did you get the new PCM? What model PCM did you get for your '93? do you have a Z/W engine? did you use the Prom (Mem-Cal) off the old one or did it come with one? Was it reprogramed or flashed?

 

my 92 did the same thing. thing would idle around 15 mph in overdrive, and i could get it to 30 when i took it thru the gears. it would stall in reverse, spin tires if id crank the wheels in gravel. sold it, and i knew the guys girlfriend. she said it was a throttle position sensor, and they replaced somethin with the overdrive(thing whined like a bi*** on the highway) It only idled at like 650-750m rpm, which i dint think was too terrible. all ik and care about that thing anymore is that it had *****! it was all stock, but i could keep up with a 97 grand prix gtp

 

Magmotor: everything ive used was brand new. my engine is W. im not sure what the "prom" is that you mentioned. thanks a bunch for your time, i appreciate it.

 

j89lumaye: yeah, its drivin me nuts...nobody can seem to figure out what it is. and yeah, mines quite a beast for bein stock too, it climbs well. just wish i had more clearance lol

 

i second the tps

possible ecm bad?

 

never tried any kind of climbin, but mine would go thru some mud/water. had it up to the chevy emblem in water, all i had were some 235 bfg a/t with 3/4 tread.....fried the starter when i did that one lol, but it was fun runnin thru the ditches like that. It hardly slowed down in that much mud