RB20DET problem *WRX sound*

[negativecamber]

hey people i need some advice,

i have a rb20det 5 spd in my S13 silvia....

tonight all of a sudden it started rumbling and it sounded exactly like a WRX boxer engine. it was making normal boost levels but the power felt lower and it was very lumpy!!!! i pulled over and had a look under the bonnet, when i gave the throttle a little twist, i could hear a sound like a hiss. i couldn't destinguish if it was an air leak or if it was like a squirting sound. (if you understand me?) but the sound was around the top of the engine where the intake pipe meets the throttle body. is this a common problem some people have heard? or will it be something to go see a doctor about???

after i stopped after and turned off the engine for 30 mins it was fine again. then it happened for about 5 minutes while driving home. what is thisssssss?????

any help would be appreciated.

[Bazelinez]

Dead coil pack dude! Guarentee it. Take off the plug cover and unplug each one individually. The engine will run even rougher on each one. When you unplug the one that makes no difference you've found the stuffed one

Mine did this when I imported it and as soon as it got warm the dodgy one would fail.

good luck.

[R31 POWER]

I had the same problem but it was a spark plug,the ceramic bit above the gap cracked and slid down to cover the spark gap.Everynow and then it would back to normal,must of been the comp pushing it back up etc.

So yer as baselinez said coil pack coz it's not sparking.

Also spray carby clean around the inlet manifold(where the top/bottom meets)join and see if the idle changes.Could be gasket or maybe just tighting of the bolts.

[negativecamber]

thank you for your helpfull insights guys

[Skyrine-Dave]

could also simply be fouled spark plugs... my rb20 suffered that a few times... Scared the crap outta me the first time it happened.

[FATGTS-R]

I have had this problem many times and had many reasons for it.

As mentioned it could be a faulty plug or a faulty ignition coil or module. It can also be caused by a leak in the inlet tract.

As you heard a hissing sound around the throttle area I would be starting there first and looking closely at the rubber joiner for a split.

And while you have the crossover pipe off may as well throw in some new plugs.

[inissane]

yeh good info guys awesome troubleshooting resource, sounds like running on 5 cylinders cause of a coil or plug

and also maybe an air leak thingo - black throttle gasket, throttle bypass hoses, plenum hoses in there too, good luck negativecamber

[negativecamber]

cheers guys again and i might check the large joiner rubber bit that links the throttle body with the cross over piping.

[psybic]

Its gotta be ignition.

Mine comes and goes just like that on my RB26. Seriously just goes into Rexy mode, then 5mins later, goes to GTR mode. (GTR is better by the way, hehe).

It has to be ignition, because if it was a cracked seal or something it would be more constant, I think mine might even be the plug going into the module, hope its not a coil pack.

[Bazelinez]

I got $50 on a dud coil pack. Its an Rb thing

[negativecamber]

will a dud coil pack come and go though? cause today the problem seemed not existent. but i bet it'll go on the weekend again. also just noticed my clutch is starting to get very slippery, so thats more money i have to spend. is the RB sound really worth it in the end??? i'm thinking maybe an SR would have been the better option

[darkrams69]

just like almost the majority of contributors on this thread, i say that it is you coils. get them replaced.

(quote:'m thinking maybe an SR would have been the better option ) believe me, the RB is way better!

[Bazelinez]

Dude, its basically the only problem the RBs have and its just due to age. Yes with my car the problem came and went until it stayed stuffed for good.

Do the test and it will prove if its them or not.

You can't blame a slipping clutch on the motor type Its just one of those things. Stick with it, the RB shits on the SR. One dud coil is the only problem i've had on mine in 6 months since I imported it. Fix it and you'll be fine! Keep us posted!

[Cillham]

happened today for the first time for me

talk about timing with thsi thread

i shat myself. i was like a mega slow WTF with a wobbling car, engine was wobbling side to side.

[negativecamber]

lol that was what i was like too, i was like: "hey cool i sound like a modded WRX!" then i started driving like miss daisy and worrying about it hahahah but i enjoyed the sound but not the rumble through the car etc.

i will try to suss out the coil packs on the weekend, and get back to you's!

[Grant]

Same thing happened to me about a month ago, it was a coil pack in my case too. I picked one up from the local wreckers for about $75, but have since found out that they can be bought off ebay for under $30....

[psybic]

So how do we test to see which coil it is?

[psybic]

Anyone?

Can you tell us how to test each coil?

Because if its going to be a matter of trialing each coil being swapped over, it could take 3 months, as its inconsistant whether it works or not. So I'll swap one, then wait a week, then swap the next one, wait another week or two and so on.

There must be some way to test.

[Oosh]

Like he said, just unplug them one by one, if the one you unplug is GOOD the car will sound even WORSE, so plug it back in and move on to another until you get to one that when unplugged makes no difference, that's the cylinder that's down.

But don't just assume it's the coil, pull the spark plug out and check it (is if fouled? clean it and see if things improve), swap a pack around and see if the dropped cylinder follows the coil, if not to loom could be damaged, etc.

If it's a dud coilpack buy a new one, or if you intend to run high-boost in the future maybe think about a set of SplitFires (~$650).

[psybic]

I say again:

Because if its going to be a matter of trialing each coil being swapped over, it could take 3 months, as its inconsistant whether it works or not. So I'll swap one, then wait a week, then swap the next one, wait another week or two and so on.

This is relevant because the guy the started the thread and myself are NOT having the problem all the time, but would like to fix it before it comes an ALL THE TIME thing.