Silvia Club of NSW

If someone has had a similar experience or can diagnose this problem for me it would be much appreciated, I am at my wits end.

When accelerating, when it starts to come on boost it starts to cough and splutter and jerk... feels like the king of all missfires happening on all cylinders and no power. Feels like if I kept my foot down it would stall. Idles perfectly, and drives ok off boost.
But other times, it purrs along, runs perfectly! I never know when its going to play up. Its definately boost related. I have changed plugs, gapped them all to .8mm, changed fuel filter, always run optimax, ran no leaks on any vaccuuum lines or cooler pipes.

I was going to systematically swap things with ppl eg. coil packs etc till I pinpointed the problem but the thing is that like I said, it can drive fine for a week then start playing up again, so that makes it hard.

Every time I have got a friend who is a mechanic to get in and see how it plays up the bitch runs like a dream.

Also if it was the ingnitors or coils, wouldnt it play up all the time? I wouldnt think that it would be such an erratic problem if it was spark related.

A few ppl have said crank angle sensor... what is confusing me is that it only plays up 'sometimes' and isnt related to heat, cold, rain, etc etc all different circumstances.

PLEASE HELP ME BEFORE I GO POSTAL


Thanks guys

hmm.. You can get things playing up in very random ways.. Have you checked all the electrical connections around the place, coz it could even be something like the connector to the airflow meter, the crank angle sensor, or even a temp sensor.
It could be worth getting some contact cleaner spray and pulling out all the connectors, giving them a spray, and plugging them back in..
I had a similar problem on a Subaru I had and it ended up being the temp sensor connector.
Also, if you can, check the ECU fault LED, it should be flashing up the last known fault, which may point you in the right direction. Unfortunately it's not as easy as it is on the Subaru, where the ECU was in the boot and you just look in and see the light, so to speak

Hi,

I had the same problem. On my one it was the Alternator that died (the car went down hill very quickly leaving me stranded, 1 week after buying the car!) loss of power etc. so goto an autoelectrician so they can do a test on your battery to make sure its putting out enought juice.

Also check your fuel filter my car was surging etc because it was blocked.

later

Neil

yeah! Fuel filter too.
good point.. Had that a few times before on older cars.

I say have a look at the fuel filter or even might be worth while draining your fuel tank next time your close to empty there might be some dirt or other crap in there.

Sarah,

Have you upgraded your fuel pump yet? If not check your fuel pressure while driving. Best (cheapest) is to hook up a oil pressure guage to your fuel line and tie the guage to your windscreen wiper. Go for a drive. If the fuel pressure doesn't rise when boost comes on (1psi for each psi of boost) then either your regulator or fuel pump is gone. As we all know fuel pumps are shit in s13's so it should be replaced anyway.

The other thing might be the coils. Does it happen at high under bonnet temps mostely?

What can happen is that the coils get very hot and changes the electrical resistance. instead of the spark jumping through the spark plug as it should, it decides, hell lets just jump outta the side of this coil thingy and earth on the block.

When you notice this happening you might like to try removing the coil cover and letting it cool for a bit, then take it for a run and see if there is any difference...

just some ideas to play with, let us know how it goes...

-Dan

Dudes... I have checked all that... except for fault codes like Dumhed said... Pump as fine (as we know yes, fine for an S13 isnt really that) titanium plugs, new filter (old one was spotless) all connections that I can find anyway lol... yadda yadda yadda.... this is why im going crazy LOL

It did have one or two minor episodes of the above a few months back, same thing but only minor (not even enough for bf in passenger seat to notice) and only lasted a couple of seconds then was fine again for a month or two, now this.

Channy, not related to driving conditions, traffic, temp, revs, etc etc. or even fuel levels also runs perfectly for a week or so at a time. BTW where the hell were you on saturday night??

ALL I CAN SAY IS THAT IT FUCKEN SUCKS

check timing lately?... but it would do it all the time if it was drastically out...

Yeah check the pewta error codes.

I've heard O2 sensor can cause strange problems...

oh Saturday night... ummm watched a movie with my g/f.

I know its those damn 18" wheels! Hey let me do you a favour... wanna swap for my sic as 16" enkei's?

LOL sorry. intimitant problems suck.

Does boost level make any difference? Not running lean?

hmmmm I'm just guessing now... what does your b/f say? oh I know "get another 4 cylinders" LOL damn V8 drivers...

I get the occasional little miss at about 3000revs under medium load. It used to annoy me until I drove several new cars that do the same thing, only more noticeably. (I think it's basically a flat spot where they tune the ECU for best emissions)
If you can check the fault codes that's probably going to be the best bet, coz you'll never track down an intermittant otherwise.. That's why the ECU stores past faults anyway.

Checking the fuel pressure could be worth doing for a while though, the regulator could be occasionally playing up. I'd also recommend trying a fuel other than optimax.. I've given up on it after getting two really bad tanks where the thing ran slow and rough till I re filled with something else.. Try the BP stuff, I haven't had a problem with that, but I normally use Vortex, although being 96 octane it's probably not the best idea.. (ok for my pansy N/A though )

_________________
The only good thing that comes in two litres
is milk, juice, and WHOOPASS!

<font size=-1>[ This Message was edited by: DumHed on 2002-02-25 17:29 ]</font>

LOL!!!! My god, you know him already
No boost levels make no difference..I have had the bleed valve closed since the problems started.
The 18's are a bit of a pain in the ass actually, unless the road is brand new it tracks all over the place LOL....

Ok dudes do I have to take it to the tuner to get the error codes out? Because I have heard stories about something little and silly being wrong that have cost thousands in dyno time to find....

If they have the proper nissan diagnostic unit they can plug it in and it'll tell them what the problem is in a few seconds..
I believe Hills Motorsport has one.. I will check on this right now actually..

Otherwise you can read up on how to do it yourself, but if you get the wrong codes to compare to or something you'll end up chasing the wrong fault for ages (I've done that before :>)

_________________
The Engine Whisperer - fixer of things

CMY180,
is your 180 a red top or black top sr20??
I have a black top and the car will run perfectly 95% of the time. Then for some unknown reason it will run like an absolute dog. Like you put your foot down and it'll really struggle to rev and it will sputter and cough, etc. Try turning your car off for 10 seconds and back on. Works sometimes so it makes me feel it's electrical related. A friend also with a black top had a similar problem. He said it was the ECU detecting detonation and putting it into a "limp home" mode?? Dont know how true that is. He works at SAS maybe u should ask him I'm sure i've seen your car outside there before.

PS. he has the white 180 there.

CMY, nah you don't have to take it to a tuner for the codes. You can do it yourself, but you will need the SR20 manual. I think some of the websites have it for download.

there is a green light and a red light on the computer. you'ld have to pull it out and check the seqence of light flashes. Yes its pretty primative... but it can be done.

You can reset the computer by unpluging the battery for some time. An hour or so. The codes will be reset, and when a fault occurs it will be recorded.

Mind u there are 5 different diagnostic settings on the computer... u will really need the manual to go further with it.

good luck.

ja, apparently the knock sensor can go faulty and it'll basically bring in a 2000rpm limit and retard the timing all the way..