real tech stumped and needs real help

[VP4prez]

ok so, i have been doing engine diag for a living for a while but im stumped on this one. i have an intermittant problem that is rearing its ugly head in the worst way today. car is my 93, s13 hatch, stock kade

cruising at whatever speed, meaning a good constant rpm, no problems. start to accelerate in the slightest and the car feels like the front wheel are way out of balance the motor vibrates so hard. but its no an uneven sputter or hesitation. its a very constant and very quick vibrating feeling from the motor. also at idle, itll drop to about 400 rpm to 700 rpm and the car will shake worse than a camed out old school muscle car.

ok now, if your thinking of reply with something as stupid as "seafoam it" or "just do a tune up" you need to go ahead and hit the back button at the top left now. the car has, as of yesterday, new plugs(oem ngks), new wires, new fuel filter. all this was done to fix another smallproblem.

the motor is a completely stock, kade with about 45k or so on it. are these motors big on fouled injectors or fuel pumps? thats my next area to tackle if i cant come up with anything else.

[Hijacker]

fuel filter was my first guess, but you already eliminated that.

Try cleaning the MAF out and see if that eliminates some of the problem. Given your idle problems, I was tempted to say it could be a troublesome IACV, but you're acceleration problems lead me to not think about it.

If you're thinking fouled injectors, try running some cleaner through it and see if your problem clears up. The only time I've had to replace injectors is when the inner seals go bad and they start leaking.

[94_240sx]

the motor is a completely stock, kade with about 45k or so on it. are these motors big on fouled injectors or fuel pumps? thats my next area to tackle if i cant come up with anything else.

3 injectors went bad on mine, so yes. My biggest challenge was bad injector went on and off, so it was hard to find where the problem was.

[MJH240SX]

i have also had to replace 3 injectors

[Flicktitty]

i've had to get the injectors replaced as well. might be something to look into.

[VP4prez]

fuel filter was my first guess, but you already eliminated that.

Try cleaning the MAF out and see if that eliminates some of the problem. Given your idle problems, I was tempted to say it could be a troublesome IACV, but you're acceleration problems lead me to not think about it.

If you're thinking fouled injectors, try running some cleaner through it and see if your problem clears up. The only time I've had to replace injectors is when the inner seals go bad and they start leaking.

it almost seems like one of the injectors will have a faulty connection orsomething because now that im focusing on the problem and not just driving the car until it goes away on its own, i am noticing a good amount of power loss aswell. ive got to be losing a cylinder but its not doing any ofthe typical cyl loss things, ie; smoking, reaking of raw gas.

i kind of want to just go ahead andreplace all the injectors if i need to replace one. im going to run outside and noid light the injectors and ill get back to y'all

[slyedog240sx]

ok so, i have been doing engine diag for a living for a while but im stumped on this one. i have an intermittant problem that is rearing its ugly head in the worst way today. car is my 93, s13 hatch, stock kade

cruising at whatever speed, meaning a good constant rpm, no problems. start to accelerate in the slightest and the car feels like the front wheel are way out of balance the motor vibrates so hard. but its no an uneven sputter or hesitation. its a very constant and very quick vibrating feeling from the motor. also at idle, itll drop to about 400 rpm to 700 rpm and the car will shake worse than a camed out old school muscle car.

ok now, if your thinking of reply with something as stupid as "seafoam it" or "just do a tune up" you need to go ahead and hit the back button at the top left now. the car has, as of yesterday, new plugs(oem ngks), new wires, new fuel filter. all this was done to fix another smallproblem.

the motor is a completely stock, kade with about 45k or so on it. are these motors big on fouled injectors or fuel pumps? thats my next area to tackle if i cant come up with anything else.

have you even put a inline spark tester to see if each cylinder is getting spark. Try to test resistance on each injector they should be at around 11 ohms.

[srpowered240sx]

sounds like it might be an issue with injector seals, making it run really rich.

[carmo]

Ever since we went to 10% ethanol I have seen alot of injectors go bad. Did you try a power balance test? Or maybe timing chain jumped a tooth. But if that was the case it would run like poop always. I would lean toward something electrical being that the problem is constant. goodluck

[VP4prez]

have you even put a inline spark tester to see if each cylinder is getting spark. Try to test resistance on each injector they should be at around 11 ohms.

spark is there and strong. the ignition system was my first stop but it fixed the other problem i was having. the biggest problem i have now is the fact that this issue is intermittent and unpredictable as of yet. point in fact, the problem is gone before i got to get to the root of it. so unfortunatelly, it looks like im going to have to wait until it decides to show up again. gay

[carmo]

Poopies!!!

[bullet7x]

I'm new to Nissans, but does it have EGR? Cause if it's stuck that could be your problem. A stuck EGR will cause hesitation and can even cause the car to die at idle.

[carmo]

Good thought but I think if the EGR valve is stuck open at cruising speed you would never really know the difference. Of course it could be a combination of things too. None the less, it's still worth a look.

[the technican]

ok i will chime in..good luck i had a 240 that would out right cut of on you while driving just at random times and it was a problem in wiring harness, you know how the big loom of harness that runs from fire wall kinda next to valve cover and then ends up near the distributor, try yanking on that harness all kinds of different ways with moderate force(use your head dont break nothing but really move it around) while the car idles and see if it messes anything up. i dont remember if it screwed up injectors or killed distributor but it might be worth looking at for an intermitant problem, good luck man