It Might Be Coil Related

[thieaux]

guys as you know i have a small problem im not getting any power after 3500 or so rpms, i think it might be coil related , ive checked everything from cats to sparkplugs , but today happend something strange i floored my car and kept looking at my tach and when it reached 4000 it started to flick like going down an up but very fast , like if the rpms where going from 3800 to 4000 and back to 3800 , i think i mightbe running rich but im not getting any blacksmoke, it just that the car reving but its not delivering power , i have no missfires no hesitations it just keeps reving till like 4000 then it just stays there screaming but no power like if its missing a cylinder BUT NO MISSFIRES.

COult be coil , pressure regulator, or coolant temperature sensor. Also low idle like 200 , Ls400 91 .

Any suggestions.

[sapper_daddy]

you said no misfires but are you getting spark to each plug? best way to test is to take one plug out, ground the threads to block, then roll motor. If you see a spark (and you will see it!) replace it and move on to the next one. The coil wouldn't be a big deal if it cost 10 dollars like american vehicles but i'd try that first. when you see each plug firing that will eliminate alot of doubts for you hopefully and you can try something else if that ain't it.

oh forgot to mention when you are holding the plug that is still in the wire's boot, hold it by the rubber when testing, those things hurt. And you may have to have someone roll the motor for you while you watch, it will be a split second, just barely touch starter and you should see your spark.

[sha4000]

the coils cost about $90 and you should have 2 one of my coils were bad and it made my tach bounce up and down but like sapper said test for spark first and if by chance your not getting any test the plug wires fir resistance and if thats good then go to the coils. good luck