car shaking loss of power.

[tmorales509]

Ok so my car started shaking recently really bad as if it is gonna die out at idle, worse when i put it in reverse or drive. Ive got it to run somewhat better to the point where it is kind of driveable but there is still a small shake and it just feels like there is no power at all. So here is the list of stuff ive changed so far.

Spark Plug Wires & Plugs
Distributor Cap
Throttle Position Sensor
Couple of hoses that had noticeable cracks
Mass Airflow Sensor
Added Fuel injector cleaner

I have also cleaned:

All connectors on the fuel injectors
throttle body
o2 sensor
pcv valve
idle air control valve

I think that is about it that i can remember. So any other suggestions as to why this is happening. Ive been up and down, side to side on that motor for the last 4 days and havent seen anything unordinary or any disconnected or cracked hoses, the only thing that i do notice is that the #3 and #4 cylinders when i pull the spark plug wire off with the car running it doesnt make any noticeable difference like all the others do.

[KA24JEF]

make sure your even getting spark? in them? might have a miss or worse come to worse you could have jumped a tooth and now timeings off but not likely

[tmorales509]

How do i check if they are getting spark? Yeah i was kinda thinking of timing but i hope not.

[KA24JEF]

you could allways take the plug wire out and stick a screw driver in the wire then make it groud to some metel lie the block if u see a spark jumps from the screw driver to the block you have spark, or at least thats the chepest ezst way

[KA24JEF]

you can even pull the plugs and see if thir fauled up or smell like gas

[tmorales509]

Alright i'll try that first.

[KA24JEF]

they sale littel screw drivers made for that at all part stores thay have a litel metel tip at the end to make it ezer and thr like 2 bucks lol

[tmorales509]

Oh. Yeah it seems like they are all getting spark to the plug but just that #3 plug doesnt decrease or increase power when i remove the wire like the rest of them do. I changed the plugs twice already though so im not sure about the plug.

[KA24JEF]

ya the plug could be getting fauled up and if nothing changes when the wire is of its ether a bad wire or not getting spark, or thirs something makeing your plugs faul up really fast when you change the plugs is thir any diff even for a ittel wile?

[tmorales509]

no there is no difference at all.

[tmorales509]

I changed the distributor rotor and still runs the same. maybe gonna test for vacuum leaks tomorrow and thinking fuel filter, o2 sensor and pcv valve..

[loystock]

In your earlier statement, you said there is no change in engine speed when you disconnect the spark plug wire from Cylinders #3 and 4. Then you said the plugs seem to be firing (during spark test) but that cylinder #3 does not make a difference with or without spark plug wire.

You may have one or two cylinders that are either dead or misfiring causing that engine shake. Which spark plugs did you use? NGK is recommended for all Nissan/Infiniti engines. Other plugs may work but using Bosch plugs can be problematic.

Have you done a 'click test' of the injectors. You can use a mechanic's stethoscope or improvise with a long screw driver and listen for 'clicking' sound with engine running to indicate the injector is firing.

[tmorales509]

I use ngk plugs and no i haven't done the click test yet, how do i go about doing that?

[tmorales509]

Can i check the injectors with a ohm meter?

[tmorales509]

i did the click test, am i listening for a fast clicking say about 4-5 clicks a second give or take? That is what i heard on all 6 injectors.

[tmorales509]

So like i said i did the click test and all injectors click the same sound and same speed however i tested the injectors with a ohm meter and all injectors 2,4,5 & 6 all read about 12.5 but 1 and 3 read around 25. Does that mean they are spraying to much fuel or something, does that mean they are bad or need to be cleaned maybe?

[tmorales509]

Well dont know what the heck i did but while i had the fuel injector connectors off i cleaned them really good since they had like a greenish builup around the connections, put them back on and started the car and no more shake..Drives perfectly normal now..I guess i should still change those injectors sooner or later though? Think im due for a fuel filter as well as oil change so i will do those probably friday and maybe i can get some injectors from a junkyard or something..

[loystock]

You're doing good. The click test is OK but the resistance check got some problems. Injector resistance is 10-14 ohms so injectors #1 & 3 are out of spec. The green stuff you are seeing is corrosion. You have to remove them and then clean with Contact Cleaner. Then apply Dielectric Grease to the connectors and retest resistance. Replace any injector that is still out of spec.

[tmorales509]

alright thanks for the help, i need to pick up some of that contact cleaner sometime this week, i just changed the fuel filter as well and running even better except for the fact that i got some gas on my hands and the smell wont come out for crap, lol.

[KA24JEF]

lol thats a good smell better then poop lol, just hope that the corrosion didnt get to far in the wire that whold cause the ohms to be out of wake and allso mean that you might need to replace the wires

[loystock]

alright thanks for the help, i need to pick up some of that contact cleaner sometime this week, i just changed the fuel filter as well and running even better except for the fact that i got some gas on my hands and the smell wont come out for crap, lol.

To be on the safe side, always pull out the Fuel Pump fuse and let the engine die, then crank a couple of times to ensure the fuel line is empty. Otherwise, you'll have fuel squirting out when you break the line.

Do the same thing if you have to replace the injector(s). Otherwise, there is a possibility of 'hydro-lock.

[tmorales509]

oh yeah thanks, i did pull the fuse and let it die however i forgot to crank it a couple times so there was still a little fuel in the filter..I'll remember that though.