S14 Misfire

[siiick]

Hi guys,

I thought i'd ask some of the clever characters on here about this, i didnt get much help from silvia forum.

I have recently bought and s14 and have noticed a bad miss at constant throttle and between 1200- 2500rpm.

When the car is completely cold the miss is not present, however once the temp gauge comes up, it begins to miss bad "car jumps"

The miss is also intermittent.

So far i have checked the coil packs for resistance with a multimeter, and have sprayed the air flow metre with electrical contact cleaner. Car runs shell 98 v power fuel, and the spark plug gaps are 0.85mm. The miss also does not seem to be present at full throttle.

Anyone have suggestions?

cheers,

Richard

[Amec]

has the car been scanned for codes?

can you see any signs of leaking around the injectors?

other causes could be a faulty crank angle sensor or faulty engine temp sensor.

if you are in Brisbane we will offer you a complementary diagnosis.

[MK2]

My bets on the crank sensor as well, when they get up a bit of heat in them on the SR20's it can sometimes make an old wonky one on the way out get a bit cantankerous. Are a pricey little critter too, pays to shop around if you do need to get a replacement but most decent workshops can sus it out for you.

After that its the loom to the ECU, given how they're wrapped around the head it can cause them to deteriorate so check the connectors and circuit there.

ECU's on the way out do some funny things as well, on the bright side, stock 2nd hand ones of those are cheap.

Usually though it's normally just a shitty plug or a coil pack that pops most of the time, O2 sensors if they've been coked up from running too rich tend to die fairly often as well.

[leb]

I also have occasional misfires with my S14.

Try the following things:

Change fuel Filter - could have some dodgey stuff sitting in there.

Check the screws are on tight which holds each coil down (dont do them up too tight that they snap).

Check the vacuum lines for leaks etc.

Check 02 sensor (check for voltage on the multimeter. from memory I think it should have a charge of >0V to <1V - tell me if its different values.

Reset ECU (just disconnect the battery for 30 mins and press the brake a few times to get rid of any remaining charge)

Check/block your EGR valve, this has the tendency to make the car "hesitant" at lower revs, if you want to block it visit this website

http://www.jull.co.uk/mods/egr.html

Let me know what the culprit is with it mate.

Good Luck

edit: what plugs are you using, are they hot, cold or standard rating?

Edited September 18, 2007 by leb

[hanyou]

hey buddy i jus got my S14 a few weeks ago with the same problem you had but only in the low rev range. however i cleaned my air flow meter and it sorted it out. i also unplugged my o2 sensor at the same time assuming it was that from what ns.com said so maybe try that too.