Can't figure it out - What's wrong?

[chrismo240sx]

93 240sx hatch ka24de....126***miles

intake, header, full exhaust...

changed plugs/wires not too long ago...look fine nownew fuel filter new cap/rotorchanged oil/filter

car sputters and breaks up during heavy acceleration but when taking it easy, its fine.....once i step on the gas past 1/2 throttle, it acts up

now a new problem, after driving (normal or beating on it) it stalls out when i take it out of gear....for example, coasting to a red light or stop sign. By the time im almost at a stop, the engine is already stalled at 0rpm, then gives me a hard time to start back up...

did a compression check too about 3 weeks ago...cyl 1 180cyl 2 190cyl 3 185cyl 4 180 so that looks good as well....

what is wrong with my car...its really annoying to drive lately so can all you fellow NICO brothers/sisters help me out...anything would be good!

[zads27]

Probably a vacuum leak or intake leak somewhere

[dnlx5]

sounds like my intake manifold leek (usually caused by the intake manifold gasket leaking where the cooland channel meets the head through the intake manifold) or a really big vacume leak. try spraying carbourator cleaner on any point that could be leeking if the engine revs up that means carb cleaner got sucked into the engine via the hole in some misilaneous hose that needs to be plugged up or in my case it was where the intake manifold met the head. but im really bad about calling evrything a vacume leak. An obvious answer would be did u mess with the timing? if so did you re set it. a timing gun helps but is not 100 percent necesary. also could one of the spark plug wires not have clamped on the plug all the way or something like that. another idea would be fuell starvation due to a pinched hose or some dirt that fel in there when you changed the filter that would seem to explain the full throttle sputtering also at idle the engine might run lean. but i think timing is more likley. there were 2 different distributors for the ka24e's and i had to know which one i had to buy the right cap and rotor or it would not work mebe the de motor has that delima too and the parts store gave u the rong one? whatever it ends up being tell us. i want to know the answer to the riddle

[dnlx5]

holy **** my post was long whops..

[chrismo240sx]

thats fine man...lots of good info and things to check tomorrow...i appreciate it a lot

i did actually mess around with my distributor timing, but the more i advance it, the better it runs, Example, more advanced...less sputtering, and vise versaim worried tho bc right now my distributor is almost fully turned to the advance side lol but like i said it runs better there, but still acts up

i guess ill check my fuel lines and vaccume lines...is that the easiest way to check for leaks?....carb cleaner spraying onto hoses?

[chrismo240sx]

would it be possible to spray some mass air flow cleaner on vac lines to check for any leaks? or does it have to be brake/carb cleaner?

[danielsan]

my 91 is acting up a little bit but not as bad as yours. 1/4 throttle is fine but more and it acts like it looses power, sputters a little.

1. could be a weak ignition coil (had a prelude that would cut out bad because of that)2. check the maf, wiring and voltage check3. check ground, clean them up a little.4. seafoam the bastard till it dies and let it sit a for a minute or two and crank that bish.5. maybe the tps is bad? i have to check mine this weekend.6. fuel pressure regulator might be bad.7. does the engine rev freely in nuetral?? i know mine does, but under load it falls on its face. im thinking my ignition coil is going out.

[dnlx5]

ya maf cleaner works fine... anything flamable te he it might also be worth it to look up a pic of the firing order and oem cap and rotor as it may be out of phase

[chrismo240sx]

UPDATE:

sprayed maf cleaner on all hoses/lines that i saw and which looked like vacuum and nothing....no increase or decrease in the idle so i dont think a vacuum leak is the problem, unless i did it wrong or left a hose or 2 out.

its not my firing order, theyre in the right way bc it only started about a week ago and before that it ran fine.

im thinking now thats its fuel related...i changed my fuel filter not too long ago, maybe there is some air in the line or something isnt right...if not filter, could be fuel pump....anyway of checking if the fuel pump is good/bad?

also may check the injectors and do an ohm test on those to make sure its not that

if im leaving other factors out, anyone is welcome for my ideas as to what the problem may be! Thanks

[dnlx5]

well it is possible to test the fuel pressure and compare it to a nissan oem value but as long as it is coming on i wouldn't guess pump. people make 250hp with their sr's on 15 year old fuel pumps all the time. It might still be worth timing your car with a timing light. daniel had some good ideas too

[lovespeed]

try this with the car running in netral spray the distrbuter and plug wires with a spray water bottle if it starts missing you have bad plug wires or coil. i have gotten bad wires stright from the parts store so don't rule it out also have you cheaked your plugs. does it idel funny if it does could be vacume leak.

[chrismo240sx]

the idle is fine for most part....every now and then it might give a little pop(quick sputter) then be normal again

i think ill try the water on the wires and coil, see if that works tomor ....like i said, i dont think its a vacuum leak as i checked that today

how would i check the voltage on the MAF sensor?

oh and if its in neutral, it still breaks up as well, so doesnt matter if in gear or not.

i ordered a coolant temp sensor to see if that will help any... all this info and advice is great and i appreciate it

..hopefully we can get the problem fixed soon without spending a ton of money.

[lovespeed]

Do you have a volt meter and a repair guide you can get a volt meter from sears for 20$

[chrismo240sx]

im sure between my dads garage and my step-dads garage, im bound to come across a volt meter....

...repair guide on the other hand, now that i dont have

[Influenced]

I had a problem just like that... after running all sorts of diagnostics... i finally found that a wire on the MAF had been pinched exposing the bare wire and during acceleration and breaking the wire would make contact with its surroundings.

Just repaired the wiring and it was all good. hope that helps.

[chrismo240sx]

ok, so ive been searching about MAFS and i think it could be my mafs causing this...other ppl have had the saem kinda symptoms when the MAF goes bad

how do i hook up the voltmeter thing to maf and check to see if its good or not?

btw...i unpluged the connecter on the maf while car was running/idleing....when i unplugged it, it idles terrible and stalled a few times lol....this mean its working properly or its going bad?

[WoolyS14DET]

Get a new (MAF) Mass Air Flow Sensor !!

[chrismo240sx]

weirdest thing happened just before....was on my way back home from the store and my car stopped sputtering or whatever, i was so happy..

then as soon as i pull onto my street, it started acting up again

anyways, heres what ive checked again so far today....another compression test but with a different gauge, read a lot lower150, 140, 145, 150 dont know which one to believe lol, i wanted to go turbo in the future but compression should be above 150 on all 4 for turbo...unless if this gauge was off.

anyways, i sprayed some water on the distributor and the wires....nothing.no change in engine rpm or anything

rechecked for vacuum leaks....again didnt find any

took out my fuel filter and drained it along with the fuel lines to make sure nothing was clogged or dirty....i blew into lines and filter when emptied and they were fine...not clogged

unplugged the MAF connector as stated before while car was running....again, it idled like s*** and then finally stalled out....did this twice

is that normal? lol what should it do when i disconnect it?

im running out of ideas as to what else it can be now ...however, if it is the MAF, what would be my best bet as to finding another one? Junkyard or eGay...i mean EBAY.

sorry for another long post, but im giving all the info i can to try to solve the problem, as for now....im thinking MAF, fuel pump/injecors (still gotta check them), or O2 sensor

[Driftstar INC]

i had a quirky problem like this a while back , My car would run fine for about 30 min's then it would start spittin and sputtering . I checked the usual spark , vac leaks , loose conections . Everything checked out . I then installed a fuel pressure gauge and went for a test drive . after about 20 min's of hard driving my sputter came back and fuel pressure was low around 22 psi.i checked the pump and it was clogged with setiment and rust . I sent the tank out and had it hot tanked and re coated and installed a new pump problem solved

[Rucca]

Go to harbor freight and buy a fuel pressure tester - I got one for like 10 bucks I think? Anyway, leave it hooked up so that when the problem occurs you can jump out and read it.

Also, when the prob occurs, pull over and disconnect fuel injectors 1 by 1. As you disconnect them the rpms should drop, then raise as you reconnect. If you disconnect one and nothing happens, you know that cylinder is the problem. Judging from your tests it would be the injector too (or injector wiring).

Your car will stall with the maf unplugged. If you start the car with it unplugged it should run in failsafe mode but this is hardly a test of anything.

[Driftstar INC]

You can route your fuel pressure tester out the back of the hood and under your wiper secure it with a peice of tape and have a buddy ride along with you with a note pad to record your readings