Bucking at 4k under light throttle

[iimagiin]

first post to nico, ive gathered so much help from this community that i figure its time to give back what i can. thanks for the help.

ive recently encountered the same problem. if i accelerate slowly in any gear it seems at 4k the motor bucks like it just hit the gov/fuel cut. under WOT there seems to be no hesitation or problem. replaced fuel filter,fuel pump(and strainer)ive been looking for a cure for some time now. i will add that i believe it may have actually started when i added an intake and cone filter.after many hours of reading, im coming to the conclusion that perhaps its my ignition coil. ill be replacing it soon so ill def. post if it helps or not.im planning on boost, so id rather get these issues worked out asap.ill be keeping an eye here as well so by all means if anyone finds a fix...post it.

[iimagiin]

well...replaced coil and adjusted timing back slightly, and it seemed to help. i couldnt force the engine to buck under light accel...or so i thought. problem returned in other gears and was even more evident in 5th. exhaust leaks wouldnt cause this would it??

[the converted]

Could be a maf problem. What is your timing set at, you should have no problem running factory timing. Are you burning oil? Have you done a compressing or leak down test?

[slipnfall]

I had crazy problems with bucking until I went with OEM cap & rotor. I needed wires also so I picked up a set of OEM as well. Make *sure* that the rotor is pressed down all the way in your distributor. Also check for abnormal arcing or hairline cracks inside the dist. cap.

These engines (DE?) seem very picky about plugs - for NA I would seriously get the NGK's (not sure on the number, BK5RE11??? or similar). Do not settle for bosch or any split-fire type...

[slipnfall]

Another thing - check your TPS and re-adjust when finished (should be 0.45V at closed throttle). With it off the TB, *sloooowly* sweep it throughout the entire range while monitoring with a multi-meter (center white wire is signal, probe for ground). Make sure you don't have a dead spots... the carbon wipers can break down over time and give odd results.

A CONSULT would be a life saver for these type of things - I suggest investing in one.

[iimagiin]

last time i set timing it was at 20btdc..i actually backed it off from that thinking it was firing too early every once in a while. i do have new wires, plugs, and cap. i have two working distributors(i say they are working) the problem exists with both.i recently (within 2000 miles) rebuilt the motor. have not felt a need to check compression since initial install and all checked well then. guess it wouldnt hurt to check it again. i took a drive today at highway speed (75-90) around 80ish it would cut every so often. but its not as noticeble as when it cuts at 4k in lower gears...just a slight "stumble". before i rebuilt the motor the vehicle had sat for 3yrs in my possession. when i first dropped the motor in i had to blast **** out of the fuel lines...im starting to wonder if possibly they arent fully clear. perhaps my injectors arent getting the gas they need. then my other thought is that i might have an injector clogged. ill check tps again, although when first setting timing and everything it checked good. i did run into a problem with a maf. a few months back but the symptoms were completely dif. ie. engine hitting rev. limit at 3k.the car pulls hard, idles smooth, and burns zero oil. thanks for all suggestions, ill be looking into them all...never hurts to double check..thanks again

[iimagiin]

after rereading your comment on plugs...i guess that opens a new door. i replaced old plugs with new bosch. but if the ka24de is truly that finicky then i guess i should explore that as well. i had bad wires when i first put the motor back in and i must say...it ran like absolute a$$. (problems solved with new wires and plugs) so i guess since those symptoms were so much worse and quite different i havent even revisited the idea of spark plugs, or wires.but revisiting i shall do. going to need them eventually anyway.