Thread: SR20 strange behavior + video!

The Nistune board was installed for me in Nistune/PLMS from Matt/Pete.
With or without the consult cable, engine works the same way. I mean this is not a reading error.
At first I also thought it is the Nistune, until I didn't put my oem ECU back and it worked the same way.

Ok, how about swapping out the distributor, I know first hand they do funky things when they go bad.

Won't help - all parts from my first post stated as 'changed' are changed due to that same issue. Meaning - having the problem and trying to deal with it I changed one after another almost everything...

I only read you changed the distributor cap and rotor in yoru first post, im talking about swaping the distributor.

My bad - this has never been done so far, engine uses its own distributor.
Point taken. I will need few more days to do such swap.
At least things I've never thought of are popping out. Hopefully one of them will help.
Thanks!

my buddys 16ve swap does that.. using the stock 16ve ecu.. also makes it hard as hell to time the damn thing.. even with the cozult or datascan the marks just dont wanna line up on the pulley right with the timing light an he's even usin a gspec pulley..

try putting the car in timing mode an advancing an retarding the timing till it runs smooth.. or maybe when you did the cam swap your a tooth off or something?

When I put the ECU in timing mode, it is not hard to set the desired timing, although marks jump a bit from time to time too. I will try playing with the timing and see if it will make it better or worse.
I've done cams changing several times so far but I've always used zip ties to have the cam gears attached to the chain. I have a picture somewhere at home from last valve cover removal, showing the pin locations at 10 and 12 o'clock when TDC.



Just tried that with no result

I was lucky to get a spare distributor today from a friend.
Just got back home after I tried it and... it makes NO difference at all So the problem is not there either..

That same guy borrowed me his compression tester again. I checked all cylinders. I don't know if the numbers are good, but definitely I think this is not a bad compression engine. You can check cylinders 2 & 3 on the below videos. It easily reaches 12 bars which I think is about 180 psi.
However I made the test on hot engine. I will repeat the procedure tomorrow morning when engine is cold.

http://tinypic.com/player.php?v=2yv9gzb&s=3
http://tinypic.com/player.php?v=2psnayx&s=3

Just did the cold engine compression test - same thing. All readings are identical to those measured when engine at working temperature.

Is it possible to have a head issue (bad valves and etc.) while good compression?
Is it possible to have all that because of a problem with the chain (loosen chain)?

Timing jumping around at idle is normal. It is the idle stablization, the ECU plays with the timing in an attempt to maintain a stable idle. I don't like the O2 sensor going to 0 volts, that is not normal. Looks like a rich condition. Remember that the S4 cams are going to give you an unstable idle due to the cam overlap. The overlap will cause it to feel like it is missing a cylinder up to over 2000 RPM, it should smooth out and run normally over that.

ECU tuning can minimize the effects of the cams but not totaly eliminate it. You could try to advance the idle timing ( through the ECU ). Is the bin loaded into the ECU the one it originally came with?

It does not look like you have a mechanical problem. If the compression is good then that pretty much rules out a valve or other engine issue. If the cams were off a tooth it would be running poorly, it sounds like it runs strong at higher RPM.

Is that the only consult type program you have? Do you have a wideband O2? What is the idle speed set to in the ECU? Have you adjusted the base idle ( done in timing mode )?