RB25DET Engine Failure, Can U Help to FiX

[Guest UnReGiStRd]

Hey,

My older bro has an R33 Nissan Skyline GTSt and has the following problems:

1, When boosting the engine is making wierd sounds

2. Wont hold Idle

3. POPS

4. One day the crank sensor will be in the middle for 15 Degrees timing, then the next it will have to be turned all the way to the right to get the same timing

5. Hesitated when boosting.

6. Fuel Ignites in exauhst

We have changed:

Coil Packs

Coil Spark Regulator

Spark Plugs

Crank Angle Sensor

ECU :spew:

/me thinks he has also tested another Airflow Meter?

[DESCR8]

Like come on, someone must have an Idea of that is going on!!!!!!!!!!!!!!!!!!!!!!!!

[hitnrun]

Looks like you have tried most of the obvious things.

Personally at this stage I would start looking at taking it to a specialist workshop.

However, exhaust popping is usually unburnt fuel. Take your injectors out and have them tested/cleaned replaced. They may be shagged and pissing out fuel.

You have changed your crank angle sensor, was it for a KNOWN working sensor? New or second hand. Do you have a second skyline to test and swap parts on/with

Also make sure your plugs are gapped to 0.8 and that your timing is set at 15-20 (if over fueling I would set it at 20 may be even test with 23-25)

Have you had a compression test done on the car? Check that you cooling system has absolutely no blocks or leaks. Check or change your thermostat.

Check for split hoses or cracks in intercooler and associated plumbing.

Personally I had surging/boosting/hesitation at 4500rpm and then again at aroun 6000rpm. Fixed with timing change to 20.

Sounds like you may have 2 different problems,

1 Your surging when boosting.

2 Fueling issues.

Timing, crank angle etc would be related I imagine, your over fuelling could be injectors, faulty ecu etc.

Oh and reset your ecu.

That's all I can think of for now, hopefully something will work for you.

Cheers,

Tim

[Guest UnReGiStRd]

1. The Crank Angel sensor is off a WORKING Nissan Skyline which is running fault free.

2. The engine was rebuilt not long ago and these problems have just arised recently

3. There is a SMALL Preferation (EXTREMELY SMALL) in the hose joiner for the intake pipe coming off the Intercooler, and it is pissing out OIL like liquid

4. Fuel pump has been changed with a Bosch High Flow Pump and i replaced the O2 sensor with a VL Turbo one and now the motor is Poping and Farting its brains out and it will not rev also, it makes weird sounds when Reving and sounds like the Motor is gonna explode. There is a Noise from the engine bay that sounds like Metal Buckling ot Rubbing Against each other.

[hitnrun]

Take your turbo off, check it is still ok, could just be a frigged seals or damages turbines. It could account for the metallica noise you can hear. Check/ compare against another working skyline turbo???

Did you do the rebuilt yourself or did a shop do it? May be take it back to the shop if done by them and see if they will cover some costs or at least some troubleshooting?

This is as far as my knowledge goes really, someone else may have ideas (more people may post tomorrow as it will be Sat)

Personally I would investigate timing/crank angle options (or what is causing the problems with the timing always being wrong)and then fueling issues.

Do you have a aftermarket/modified ecu or s-afc? Could that be playing up and causing the timing to change? What about knock sensor?

Not sure about the O2 sensor, meggala's site suggests

02 sensors

They are the same as ford ef-el one just cut off the plug and fit the nissan plug about a third of the price.

May be that could be your problem.

Also have you checked the cam timing?

[SiX]

timing belt?

[Guest UnReGiStRd]

A Mate Rebuilt it for me, He is a Mechanic, it was going good for a couple of months then this just started recently

[DAMQIK GTS-T]

I have the same problem as you with my r33 gtst,

if and when you find the fault let us know what it is.

more things to check

1. the pin that alignes the crank angle sensor in the exhaust cam its in the camshaft and is half a circle shape looking into the cam and outer to it there is a star shape slot also remove the cas you will see what I meen (this pin has been known to snap / bend causing eratic timing).

2. the vl o2 sensor is the wrong one for a r33 will not work with the factory ecu.

3. the resistor in the boot near the jack side Mounted neer the power antanna motor.

4. vtec solidnoid near the no1 injector (could explain that tinny rattle)

5. behind the ecu is two relays check for resistance across the contacts in both normally open and normally closed modes (powered and not) as there are two sets of contacts in one of them.

I have checked most of the things that you have checked including replacing the crank sensor ignitor and ecu withother known working ones.

the above list is what Iam checking in my car this weekend are things that I am yet to check in my car as I now need to do some through checking as the prob started off small but now the car is undriveable

I have tryed ecu resets and diag mode gives me code 55 (all is good)

though my vtec isnt working! the car is running so rich that im getting about 150 k to a tank.

good luck with yours

Regards Damqik

[Guest GR33DyMANGO]

i dont know to much, but running some 'injector cleaner' through the car usually does it good. especially if the problem is stemming from the injectors.

[hitnrun]

i dont know to much, but running some 'injector cleaner' through the car usually does it good. especially if the problem is stemming from the injectors.

Shouldn't be injectors, as it seems to be running rich, blocked injectors should make it run lean??

Damqik's injectors are sadly pretty knackered, they have been taken out and examined.

At this stage UnReGiStRd, I would try changing to a genuine Skyline O2 sensor.

Also isn't there 2 osygen sensors? One in cat and one near turbo?

Good luck.

[kjb_r33]

One in the cat is a EGT sensor.... (temp)....

with all your symptoms, the first thing id be checking is valve timing, maybe your belt tensioner is knackered, and the timing is slipping...jumping teeth....

Are the RB engines free running, anyone know???

[crooser]

1, When boosting the engine is making wierd sounds  

2. Wont hold Idle  

3. POPS  

4. One day the crank sensor will be in the middle for 15 Degrees timing, then the next it will have to be turned all the way to the right to get the same timing  

5. Hesitated when boosting.  

6. Fuel Ignites in exauhst  

AFM would be my guess

[NutR33]

no the rb25det are not a free spinning motor, i have seen the carnage the a broken cam belt will do and its not pretty - luckly it was not my motor. lol

[gtst25]

Someone had a very similar problem with a ca18det.

Ended up being where the cas joins the camshaft - someone didn't install the cas properly and stripped the lobe off.

Result - timing all over the place and an engine which didn't like running.