Rb20det Timing/IDLE

[PROJECTRB240SX]

I KNOW THE STOCK RB20DET TIMING IS 15 BTDC BUT WHEN I RECIEVED THE ENGINE IT WAS TIMED AT 30 BTDC. IT RUNS A HELL OF ALOT FASTER AT 30 BTDC THEN IT DOES AT 15. THE ONLY PROBLEM IS THAT AT 30 BTDC IT IDLES AT 1100RPM AND AT 15 ITS IDLES AT 650 RPM. IS THERE ANYWAY TO ADJUST THE IDLE AT 30 BTDC TO IDLE AT 650RPM?

ALSO I THOUGHT THAT WHEN YOU RETARD A MOTOR IT RUNS SLOWER? OR DO I HAVE MY DIRECTIONS MESSED UP AND I'M ACTUALLY ADVANCING IT?

TIMING MARK QUESTION: ACCORDING TO MY JPNZ BOOK IT SAYS THAT THE MARK ALL THE WAY TO THE LEFT IS 0 AND THE ONE ALL THE WAY TO THE RIGHT IS 30, IS THIS CORRECT OR *** BACKWARDS?

[Joe]

set it to stockyou are running some serious advanced timing.

turbo motors + advanced timing = bad

[PROJECTRB240SX]

IF ITS BACKWARDS THEN I'M RUNNING AT TDC INSTEAD OF 30 BTDC.

[PROJECTRB240SX]

THIS IS HOW IT WAS SHIPPED TO ME, IT HAD A TIMING MARK PAINTED ON THE CAM ANGLE SENSOR.

[IvoryJ30t]

well, on the crank pulley, marks on the right are BTDC and decrease to the left untill you get to TDC. not sure if RB pulleys have a few degrees of ATDC marked, it may end on the left with TDC.

[IvoryJ30t]

and a base timing of 30 degrees BTDC is really really really bad.

[Joe]

it needs to ignite as close to 15 degrees BTDC as possible.

firing @ TDC would make the car run like complete **** because not all the fuel would be igniting.

as far as i know the first mark on the RB crank pullies are TDC and go to BTDC from there.

[PROJECTRB240SX]

WELL STOCK THE MARK IS AT THE ONE FURTHEST TO THE RIGHT. I ADJUSTED IT TO THE MIDDLE ONE AND IT RUNS LIKE ***.

[IvoryJ30t]

yeah, there would be no point in marking atdc on the pulley, because if your igniting there the car will probably have a hard time pulling out of its parking space.

[IvoryJ30t]

woah woah woah, are you talking about the CAS???

if so, turning it counterclockwise will advance ignition timing, and clockwise will retard the timing.

[PROJECTRB240SX]

OK MY CAS WAS MARKED FROM VENUS. WHEN I PUT A LIGHT GUN ON IT, IT SAID 30 BTDC 9IDLES HIGH BUT IS REALLY FAST), I THEN TURNED THE CAS CLOCKWISE UNTIL IT READ 15BTDC (WHICH IDLES RIGHT BUT RUNS SLOW).

[Wulfgang]

Last mark on my RB20 crank pulley is at 0º. First mark is at 20º, iirc. Your manual is correct. The first mark to come around is the right-most mark since the crank turns clockwise.

[PROJECTRB240SX]

YES..... SO ACCORDING TO MY MANUAL I'M RUNNING AT 30 BTDC, WHICH IS THE FASTEST SETTING I HAVE FOUND BUT IDLES THE HIGHEST, ANYTHING LOWER THAN 15 DOESN'T IDLE AT ALL.

[IvoryJ30t]

count the marks

if it looks like 1iiii1iiii1iiii1iiii1then you want to time for the second to last big mark on the right.

[IvoryJ30t]

also, do the RB motors have a base timing check connector?

you may have to ground out a terminal or remove the TPS connector. [just the harness, not the tps]

[PROJECTRB240SX]

SO HAVING IT 15 ADVANCED IS BAD? :devil

THE MANUAL DIDN'T SAY ANYTHING ABOUT REMOVING ANYTHING (ITS THE FIRST THING WE CHECKED FOR).

[IvoryJ30t]

most of the time DIS ignition systems need to have a base ignition timing check connector grounded or unplugged, or the TPS unplugged to check and set the base ignition timing.

[IvoryJ30t]

no, 15 BTDC is good, just not 15 over 15 degrees.

30 BTDC is kinda a recipie for piston soup.

unless you like running 116 all the time.

[PROJECTRB240SX]

OK IT COULD BE MY COOLING ISSUES THEN AND MAYBE WHY THE ENGINE IS SMOKING.

[IvoryJ30t]

you loosing coolant?

[goofynick6]

Unplug the TPS, and make sure your timing gun has any delay set to zero. Then with it idling it should read 15 btdc, which I am not sure which tick mark it is.

According to ivoryj30t that would be the 3rd mark in from the left?

If yours is on the last mark, that sounds like 20 deg.

NIck

[Carl H]

dude, had this problem with my rb too.if you have the jpnz book then set timing to that.with the rb20 you do NOT need to disconnect the tps, this only sends the ecu into some weird mode (possibly limp home mode).you first need to adjust the idle, and thats controled by the AAC valve that is on the back of the intake plenum.once that has been lowered change the timing to 15 degrees btdc, that will be 3 marks from the 0 degree mark as it is increments of 5.set timing there and let it be.mine was set at 30 degrees and it pulled like a cut bastard on the weak ignition maps, when i reset the ecu it would ping like a *****.resetting the ecu after setting the base timing will make the car pull like its set at 30 degrees but with the saftey of the ecu putting the right timing out.oh yeah, the 0 mark is orange or some other odd colour.but it may just be a darker white.

[Wulfgang]

You are doing this with a timing strobe, aren't you??? If you're just talking about CAS marks someone painted, then there's no telling where your timing is set.

[PROJECTRB240SX]

I've done everything but what carl has said.no i'm not losing coolant.

so basically I start the car and adjust the idle to 650rpmthen time it to 15btdcshut the car down and unplug the batteryhold the pedal down to clear the ecu then plug the battery back in and start it up?

[Carl H]

yeah.i cant seem to get my idle under 700 rpm, so thats where it stays.set timing once the car is warmed up because its gonna be cold starting for a bit and will have a high idle.set the timing to 15 degrees by moving the CAS.shut the car down.disconnect the battery for 20min.plug it back in,start her back up, and check timing.should be at 15 solid and if it is then take her out and go balls out, as this will remap the ignition curves.

[Carl H]

dude.change your o2 sensor.the one that works on our cars is from a 1984 200sx with the ca18et engine, bolts right in.my old o2 was fubared and it ran rich as hell and wouldnt idle.put that one on and it immediately fired up and idled really smoothly.once out on the road you could feel the power increace as the car wasnt running super rich, so the power was there and wasnt laggy like it had been.i would still check timing and then swap the o2 sensor out.

[PROJECTRB240SX]

timing and idle are perfect i have an extra o2 sensor that i plan on swapping in later this week.

[Carl H]

well if it idles and timing is good then dont bother with the o2 sensor.but if it smells like your car is carburated out the exhaust then perhaps changing o2 sensors is a good thing.

[PROJECTRB240SX]

WELL THIS LOWERED MY ENGINE TEMPS QUITE ABIT. I STILL SMELL UNBURNED FUEL SO I WILL CHANGE MY O2 IN HOPES OF FIXING THIS PROBLEM.

[frosted flakes]

where is the alignment timing mark on the rb20det engine? i see the timing marks on when the light is on it but where do i align it to. i think i need to retime my engine since my engine has the "dieseling" affect after engine shutdown..