motor shakes but cant find anything wrong

[awd2ks4]

Need help with misfire problem

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hi guys new to the forum. Hopefully you guys can help me out with my first s13. Its a 93 ka24de hatch mt and seems to misfire cause it shakes real bad whenever you touch the gas pedal, idle is around 1k rpm and seems pretty good but you can tell it has a slight misfire still. I can rev it up as high as i want it just shakes real bad like the whole car and shifter. It also shakes when starting it. Its all stock with 170k miles, no vacuum leaks as far as i can tell or find. I added new ngk spark plugs gapped to spec, new plug wires, new cap and rotor, new fuel filter, cleaned the IACV. Pulled each spark plug wire one at a time to see if i could isolate it to one cylinder but when each wire is pulled it makes the engine want to die like it should so it seems to be working. I did the same thing with the fuel injectors and had the same result. Tested the injectors for the proper ohms and voltage all checked out fine. I swapped in some new plugs thinking i had a bad set and they were pretty black with a little white sote on the very end. I checked for codes and got fault 55 meaning everythings good. I tested the tps .55 volts closed and 4.5. any ideas?

[SoCal-S13]

motor/trans mounts?

[awd2ks4]

motor/trans mounts?

yeah both are good this is really starting to confuse me

[nofatchicks0073]

check your mass air flow sensor try unplugging it and see if anything changes that would be the next thing i checked

[awd2ks4]

check your mass air flow sensor try unplugging it and see if anything changes that would be the next thing i checked

If i unplug the mass air it will still act the same except cut out at 3500rpm which i believe is normal. ive checked all my grounds. ive yet to have any progress. I also painted the valve cover too if that could have anything to do with my problem (i highly doubt) Its really weird i can crack the revs no problem but if i hold a rpm like when smog testing it sounds like its misfiring to me. Ive replaced everything spark related besides the coil,ignitor and distributor itself.

[Fbomb19]

I have teh same problem with my s14. Its all stock and it does exactly that from time to time. It doesnt do it all the time only somtimes. And it comes and goes. So IDK WTF it is. ive replaced everything. >.>

[nofatchicks0073]

damn thats the worst kinda problem the one that only happens "sometimes" but never when you trying to figuere it out anyways check really well for any vacum leaks and look around your air intake after the mass air make sure you dont have any unmetered air getting in there you could possibly have a crack somewhere that doesnt open up untill you hit the gas and the motor jerks a little its happend to me before anyway......... andd yes yes i know holy run on sentence batman im not very big on punctuation

[awd2ks4]

well it happens all the time never goes away. I need more ideas. im hinting towards an electrical problem, i took the air intake off last night trying to find any kind of tears or what not and found none. whats the symptoms of a bad dizzy?

[hondakill3r75]

im have a similar problem. i got a rebuild 24kaDE and every now and then it gets the shakes, feels like its bogged down, no power...or pull should i say. check engin light is on, smokes after i sit at a light and take off.... but not all the time... WTH?!?!?! hummmmmm

[qwertyz]

if your car seems like it missfires it probably IS
Vacuum leaks plugs wires ETC

introduce alternative fuel (carb/throttle cleaner) RIGT BY THE INJECTORS ON THE INTAKE MANIFOLD ON CYL 4
and see if your miss will go away. (if it does, change the intake gasket because it's cracked)

[OutToWinPAHC]

Have you timed the motor? You may want to do plus, cap, rotor, injector o rings and time the motor.

[awd2ks4]

So ive tried a new maf from a friends car, tried a another distributor, checked the timing, tried my friends ecu, Ive already replaced the spark plugs, wires, cap and rotor too. I did a compression test which came up good. I tried seafoaming and my dad seemed to think it was smoothing out when i was spraying the seafoam down the throttle body. But it still the same, seems like its missing slightly on all cylinders. Had my mechanic friend verify fuel pressure also. When driving, it seems like the car is low on power and stutters on part throttle pretty bad. Right now im completely out of ideas, i just want to beat this motor until i can piece together an ls1 swap. Please help!!

[THE_ROOK_671]

First if the motor shakes really bad i would double check my motor mounts and transmission mount. my previous s13 hatch was shaking utterly bad due to this. Im not to sure but i believe it MAY have something to do with a misfire...like i said not sure.
also have you cleaned your throttle body? i know you said you put seafoam down it but try cleaning the plate and where the plate sits. if it has a lip of carbon build up the plate will not sit right causing a bad a/f ratio. Also try cleaning the electrical connectors i.e. dizzy,maf,tps, etc there could be some high resistance on those connectors. Try cleaning the maf also if it has a bunch of oil or dirt in it or on that hot wire then it will also give a faulty reading. And you mentioned it has no power on acceleration almost half of the time it is the timing being wrong. check and see if you jumped a tooth on the chain or if you put the dizzy in wrong.