gtr limp mode - now not starting... help :/

[thieves]

Skym: thanks, so i should reset the ecu if for some reason my ignition timing is set to 0 now? then try the timing light and making sure everything is where it should be (cams, check timing belt didnt skip, and adjust CAS accordingly?) Anything i should read about doing this stuff?

[Skym]

ECU should make engine run as it normally would (doesn't detect knock) once you solve the knocking problem.

Knock could be caused by -

Failing fuelpump (lean A/F ratio)
Faulty FPR on fuel rail causing low fuel pressure (lean A/F ratio)
Airleak (lean? A/F ratio)
Incorrectly adjusted CAS (too advanced ignition timing)
Running low octane gas

But since you said CAS was adjusted, that's where I would look first (too advanced ignition timing). If running on low octane gas, doesn't help.

CAS is fairly easy to adjust -

1.) Connect timing light to little loop of black wire that sticks out of loom (coilpack loom) on drivers side of ignition module. Ignition module is located on top of back of engine. Also connect timing light to battery.

2.) Unbolt CAS bolts x3 with engine off, so you can rotate CAS.

3.) Turn engine on and aim timing light at crank pully / damper and should see orange looking marks on pully / damper and white mark on lower cambelt cover. Also I think there was a white mark on pully for 0 degrees. Every gap between orange marks is 5 degrees, so need 3x 5 degrees = 15 degrees or 3x orange marks from white mark.

4.) Turn CAS until you see 15 degrees on timing light or 3x orange marks on crank pully from white mark on crank pully.

5.) Turn engine off, retighten CAS bolts x 3.

6.) Your done.

Some prefer to use a HT? lead on coilpack no1, as get more accurate reading than using the loop of wire that goes to coilpack 1 from ignition module. The reason why is ECU can add ignition timing + adjust timing + or - 5 degrees (idle stabilisation) and that signal goes through that loop of black wire, which can make adjusting CAS accurately harder (frustrating).

I was saying ECU has main maps (ignition map, fuel map), knock maps (knock ignition map, knock fuel map). When unstable combustion (knock) is detected by knock sensors + ECU, the ECU switches to knock maps.

On a GTS model with RB25DET (high compression) engine (you have a GTR with RB26DETT engine) the ignition timing can be pulled back as far as 0 degrees (knock ignition map) when knock is detected and engine stops accelerating.

Also knock maps are known as low octane maps, which ECU uses when running on low octane gas (engine can knock on low octane gas with main maps).

[TW]

Lol whoops, didn't see page 2.
Timing definitely sounds off, start there for sure.

[Skym]

I agree. It's due to ECU revlimited engine to 2500rpm, which can happen when ECU doesn't see MAF (disconnected MAF, MAF not working).

But doesn't hurt to check base ignition timing.

[thieves]

Alright, So we started trying to adjust the CAS and everything with the timing light etc, guessing we arent doing it right but i also need a new battery.. had to keep on jumping my car.. The car started up but then cas adjusted and leaned it out now its not starting again.. could just be the weak battery maybe. Will get a new one in the morning.

[Skym]

If battery is below I think was 12V, dash can beep and from what I can remember one of the warning light's on dash light's up. But can't 100% remember which warning light (I think I posted which light in the past). Might have been HICAS warning light. Some warning light's on dash have 2x purposes. Also starter won't turn over.

Another thing to check is alternator after fitting new battery.

[archaeic_bloke]

what a nightmare this must be for u,. any progress?

[thieves]

hah yeah its pretty terrible. Just got the car and just want it to run how it should stock.
I found a shop down here that has worked on skylines and other imports before. I'm going to have another go at the timing later today with a fresh battery and try it another way (instead of using that wire, using the coil pack way that is more annoying). I'll post an update later if i have some luck or not.

[thieves]

So we got a new battery and we got warmer plugs and gapped them .30 plugged those in. Set the cas as center as possible set crank pulley to 0 degrees while tps was unplugged tried cranking it and it won't do anything.. The starter is giving out after awhile so we stopped.. Sigh, never ends.. It sounded like it wanted to start but no go..

[derbeck]

I'm thinking igniter by the sounds of it

[Skym]

Your meant to set CAS to 15 degrees BTDC (Before Top Dead Centre or before piston reaches Top Dead Centre), not 0. Engine shouldn't start if set it to 0. I was saying count 3 x orange marks (gap between orange marks is 5 degrees of crank rotation) from white line, which I think is O on crank pully. That should set it on 15 degrees BTDC. Also timing light should display 15 indicating you have it set correctly.

Gap for sparkplugs should be 0.8mm, NGK PFR7A (heat range) if you have intake, exhaust. Factory is 1.1mm (11 on end of part number) and NGK PFR6A for heat range.

[thieves]

Thanks a lot for the help skym. I will give it one last try tomorrow and if i fail again im going to bite the bullet and tow it to a shop hoping no serious damage is done ( i read some forum posts saying can do some valve damage which gets pricey ) We did another compression test also was 160+ all around.

[thieves]

We got the car to start today fine after adjusting stuff correctly, then after the car warms up, fuel breaks up and idle gets rough then it wont rev and eventually shuts off to not turn back on now. (also the locating half dowl on the cam for the cas snapped off, but we can get it set in the right position)

[Skym]

The CAS key looks easy to break off inside shaft. As long as it hasn't worn the front of exhaust cam, should be ok. R34 CAS are known to wear front of exhaust cam.

Could be fuelpump is on the way out or voltage regulator to fuelpump is playing up. Clogged fuelfilter can be the common cause of fuelpump failing earlier than it should. FPR is faulty (pulling vacuum hose to FPR should make fuelpressure rise and is way of checking FPR).

Fuelfilter should be done every 20,000km or less. Fuelpump changed every 100,000km or so (can use fuelpump up to 140,000km, but best to replace fuelpump at 100,000km).

[M13]

which way is advancing for CAS?