Miss Fire High In Rev Range Rb20det

[rb20siliva69]

hey guys,

I recently had my cooler piping redone in my silvia so my bonnet would close properly it has any rb20det in it, anyway when i got it back from the place i had redo the piping.

I took it for a drive and high in the rev range not quite sure where (have not replace tacho yet) it looses all powerand miss fire's badly for about 30 seconds during and after giving it a bit of throttle and then idels fine.

you can rev it on the spot and it is fine it is only when driving when it is under load.

I think it might be a coil pack but i tested all of them with a multi meter and they all have the same reading and the spark plugs are fine they have been in ther for about 45000 there iridium ngk plugs what do you think is wrong with it i also found that the place i had do the piping did not clean out the piping properly it had metal filings still in the piping still have to do a compression test but the power delivery is fine untill it starts to miss fire so i would assume that the compression is fine, it seams to be ignition to me but please

Help!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Green_s13]

it sounds like something is heating up and you are getting a vacume leak i.e. a rubber joiner when heating opens a small hole and when the heat goes out it seals up again.

[darkl0n]

sounds like a boost/vac leak, my car did it for a while till i found a hole in the piping, it would go sweet and then all of a suddon it would cut out under load and the tacho would go nuts.

[TTT]

there are a few things you can do which will cost you nothing or very little that may sort out the problem.

1.) replace those 45000km old spark plugs… Get yourself a set of copper plugs in the correct heat range (do a search for skyline spark plugs to get part number), make sure they are 0.8mm gapped and recheck them with a feeler tool.

2.) Take out those coil packs. Get some good electrical tape (not the 6 rolls for $2 kind) and tape up the rubber parts all the way from the spark plug end up to the coil pack end. I went up and down mine with 3 layers of tape.

3.) Take out your AFM, get some degreaser (or electrical contact cleaner, they both work) and spray the inside of your AFM… rinse it out, (do it again if not completely clean), then dry it out before fitting it back to the car.

There you go.

3 things that will cost you some of your time and maybe $30 for 6 plugs and some electrical tape and can of degreaser.

If these things fix it, all good.

If they don’t, all you’ve done is wasted a few of your hours.. but now you have good coil packs, new spark plugs and a clean AFM, and can be certain it’s not those causing the problem.

[Limmy]

great advice GTST . Im going to give that a go to my car this long weekend.