dnersten

i have a 93 4runner ran great all of a sudden went down hill 4 and 6 cylinders arent working have checked, power to injectors, injectors, plug wires, compresion, and pugs are getting spark. also has brand new plugs and motor is running really rich i did an auto to manual tranny swap and never changed computer but it has ran fine for 2 or three months any ideas why this happening?

oldblue

i assume you did a "poor mans cylinder contribution test" to find that #4 and #6 are the problem cylinders. basically, with the engine running you pull a plug wire from each cylinder one at a time and note which cylinder(s) don't have an affect on idle. what were the compression readings on all cylinders? #4 and #6 are next to eachother, a blown head gasket could cause this. for these cylinders you can easily access the fuel injectors, using a stethescope or long screwdriver can you hear the injectors clicking?

dnersten

Ya that's how I checked them all #2 #4 #6 all had over 150 psi of compression and ya took injectors out put power to them and seen if they clicked also put a diod light I think it's called on the injector wires while it was running and they had power

oldblue

was the noid flashing or just a constant light. i like to listen to each injector i can access and compare the noises (clicks). what were the compression readings on #4 and 6 compared to the other cylinders?