RB20 probs

[Mase]

Just a few things i was hoping some of you might be able to help me on. My rb20 in my silvia is only getting roughly 330klms out of a tank. The tank size is 55L. This was with relatively easy driving etc. Also, the cars idle rises and falls dramatically sometimes at idle. Does anybody have any ideas what i should be looking for as to fixing this problem? All the rb has done to it is a k & n air filter which came off the old engine that was in it. Thanks for your help.

Jase

[Steve]

First thing I would be checking is ALL (and there are alot of them) of the hoses to and from anywhere on the intake line.

I had this problem and it was a leak.

Secondly, check your BOV, as if this is leaking, it will cause a similar prob.

Out of ideas now:)

[BHDave]

Check the idle control valve, or whatever its called, on the back of the plenum. Pull it off and hit it with carby cleaner. They tend to clog up a bit and cause a fluctuating idle.

That economy is pretty bad, I get min 400kms per tank local driving with filter, exhaust, intercooler, boost controller and i don't really drive slow. Up to 530km on longer distance driving.

This is generally taking 53-55L when i fill it up. RB20T aswell.

[Cool Hand Luke]

I would almost bet my left whatever that its your oxygen sensor. I had the same problem with my car, disconnect it and see if it idles better. When i got a new one, the idle was perfect and a big difference in fuel economy (I had to disconnect the faulty one till i found the new one)

[Mase]

I think the problem has been solved. My ignition timing so was retarded it wasn't funny. Now it seems to be very conservative on the petrol and is going heaps harder!! Still have the occasional up and down idle tho so i will take that valve off and give it a clean. For all your rb20det people, i peaked power at 7200rpm, does this sound normal??? The dyno i was on was a bit out of whack too cuz i only got 73kw's at the wheels!!! hehe.

[S13 Silvia]

Yeah, I had the same problem after my conversion. While doing the conversion, in an effort to work out why I wasn't getting ignition, I mucked around with the crank angle sensor and when I finally got it going, it was retarded so on idle, it would nearly cut out then rise then nearly cut out again, one of the first things I checked was the CAS and this solved the problem.

[MM2death]

Dirty AFM is also a culprit for inconsistant idle.

Scott

[Col-GTSX]

Most importantlly run a compression test.....

If she is a red top like my old motor... Sounds like a dropped ring or blown head gasket.....

[Col-GTSX]

It most likely will be one of the above... Im just making you aware.... I have 150psi on a cold motor cyl 1-5 and then cyl 6 was 50psi....

[Mase]

It doesn't do it all the time tho, only occasionally. Once every two days or something, then it stops.

[williamc]

hmmmmm im only get 300km or less to a tank....... and I dont drive very hard

Will