Hi i have a auto non turbo vl that has 270,000 k's that i find to be a bit laggy when i rev it ( this is in comparison to my other vl and some others i have seen). It is by no means a **** motor i just cant understand why it is not as responsive as the rb30 in my other vl which revs up instantly and sounds very strong (sounds smoother, quieter yet angrier too. you can really hear it sucking the air through the airbox). the car its in also feels as if it has wayyy more torque than this motor im having trouble with. both are completely stock rb30's with stock intake and exhaust manifolds and 2.5" systems. (i dont believe the cat is the problem either as this exhaust was off my other vl) Basically when you rev it it just doesnt feel as strong as it should and its almost as if it hesitates very slightly before revving where as the other motor can rev up as quick as you pull the cable and sounds crisp as. I did a compression test and all cylinders were 175 psi (1200kpa) except number 4 wich was slightly higher at about 180 psi and that plug was slightly fouled. Also did a quick mixture test at 2000rpm on the ecu and both lights flash continually at the same time like they should. All the connections are clean, intake manifold pulled apart, cleaned and put together with new gaskets, cleaned and swapped many o2 sensors, new air filter, new oil, new fuel filter (on the right way), flushed radiator and filled with coolant, new plugs and leads and i run through a oil flush and some injector cleaner every time i service it. The timing is set at 15 degrees btdc and i have also tried it on 20. I always use 95 octane fuel. Now here are some things where i think there may be a problem or just things i've noticed. I've noticed the external fuel pump is getting noisy, i can hear it while i walk around the car. before i cleaned out the inlet manifold there was a fair bit of carbon build up and even some oil film which had me worried. i've been told this is normal. possibly since the pcv valve vents into there and the oil may have been too high before i got a hold of the car. I can smell what i think is an exhaust leak in the engine bay however if its there it must be small because i cant see anything. Can also smell it in the cabin sometimes. I'm slowly losing coolant from the overflow bottle however i can not find leaks anywhere in the bay or around the overflow bottle or radiator. I dont think the heater is leaking either, a new TPS has been put on and may not be adjusted right, im not sure if the timing belt is out a tooth or not, AFM is yet to be tested, the motor hesitates and splutters for a second when first started and cold then kinda drives normally but with a little less power than when warm, the temp doesnt go up for a very long time i'm thinking the aftermarket thermostat could be stuck open. On the ecu i used to get no fault codes (code 44) but now i coolant temp sensor, TPS, vehicle speed sensor, neutral switch, air con. dont quote me on them because i'll have to recheck them again after resetting the ecu. I'm also thinking there could be somthing wrong in the head like seals or valves or possibly a very small head gasket leak letting coolant into the cylinder. I realise the old auto box could have alot to do with some of the slowish accelleration however there definately is a problem with the motor itself So let me know what you think and if anyone has some experience with troubleshooting Rb30's or have had the same problems your assistance would be much appreciated. thanks, Jamie.

The compression is fine by the sounds of it. though there may be a problem with the injector for that cyl. If it was a problem with your valves it would come up crap on your pressure test. it would have to be a pretty big exhaust leak to affect the performance that noticeably, aftermarket thermostats are crap. at work we will only ever use genuine ones. I'm not sure the TPS could have much to do with it? But honestly if it was my car. id get the injectors cleaned and flow tested including replacing the small filter in them. if that doesn't help id pull off the front cover and check the timing marks are lined up correctly. Its really just too hard to say without driving the car and hearing it run. Hope this helps somewhat.. ---------- Post added 10-11-11 at 20:37 ---------- by the way for "that cyl" I mean the one with the fouled plug, as it may be running lean. also as you said the fuel pump is noticeably louder, if you have access to a flow tester id try that and see. should be around 200kpa or something near that anyway. and check your fuel filter again just in case.

Have you checked the timing? The TPS will also need setting. The factory ecu as you crack the throttle does a double fire of the injectors, kinda like a accel jet in a carb to avoid a sudden lean spot which can cause hesitation.

Quote: Originally Posted by VLforced [View Post] by the way for "that cyl" I mean the one with the fouled plug, as it may be running lean. also as you said the fuel pump is noticeably louder, if you have access to a flow tester id try that and see. should be around 200kpa or something near that anyway. and check your fuel filter again just in case. I'm studying diesel fitting right now so when i'm at tafe next week i'll see if i can use one of their flow testers while im there. Also where is the best place to buy a genuine nissan rb30 thermostat? online? i'm in brisbane. I knew aftermarket would be **** and it was but i just needed something at the time till i could get a hold of a genuine one. ---------- Post added 10-11-11 at 21:36 ---------- Quote: Originally Posted by Duke57TT [View Post] Have you checked the timing? The TPS will also need setting. The factory ecu as you crack the throttle does a double fire of the injectors, kinda like a accel jet in a carb to avoid a sudden lean spot which can cause hesitation. Yeah my timing is at 15 btdc. i havent check the actual markings on the belt though but i will be soon. Because then the cam will be out if the belt is right. because if say there is 12 teeth on the crank gear and 24 on the cam gear it's gonna take twice as long for the cam to do one rotation in relation to the crank and the response would probably be **** even being out a tooth or 2. but then it wouldnt idle very good would it? the TPS i will check i just have to figure out how to use the multimeter on it at different positions because of the multiple switches inside of it opening and closing at different points of opening and closing. not really something i have done before. I'll see how i go.

Honestly man I've never actually bought one. I am also guilty of putting an aftermarket one in about a month ago, our Nissan and Holden dealerships didn't have one on the day and the only ones I could find online just then were $150 Nismo ones, One of your dealerships there might have one.. guess just ring them and see. Also if it were out 2 teeth you would probably know about it lol.

You mean the cam with rotate twice as fast as the crank Grab yourself a Gregories VL Manual, invaluable for crap like that. Was the cam belt touched? Pull the top timing cover off, pull the plugs out, mark the belt and count your teeth. It could be 1 tooth retarded. Some original photos have not been recovered yet.

Quote: Originally Posted by Duke57TT [View Post] You mean the cam with rotate twice as fast as the crank Grab yourself a Gregories VL Manual, invaluable for crap like that. Was the cam belt touched? Pull the top timing cover off, pull the plugs out, mark the belt and count your teeth. It could be 1 tooth retarded. haha possibly i confused myself now. I'll be checking the timing belt tomorrow. if thats fine is it possible the dizzy could be out a tooth or would that only affect how far you can advance or retard the timing? at the moment i have a max ellerys manual and i've also borrowed the full volumes of the original holden service manual from the tafe library. i cant believe how much better the holden manual is compared to anything you can buy from the shops. they really dont leave out anything. bet they would be a fortune to buy though. ---------- Post added 11-11-11 at 12:52 ---------- Quote: Originally Posted by VLforced [View Post] Honestly man I've never actually bought one. I am also guilty of putting an aftermarket one in about a month ago, our Nissan and Holden dealerships didn't have one on the day and the only ones I could find online just then were $150 Nismo ones, One of your dealerships there might have one.. guess just ring them and see. Also if it were out 2 teeth you would probably know about it lol. Yeah theyre hard to get a hold of. if i cant find one around in the stores i'll try my luck online. with the old thermostat in the car ran much better and would drive fine even when cold. even looking at an aftermarket thermostat next to a genuine one you can see how much they lack in quality. Some original photos have not been recovered yet.

You can make any bet that the injectors have had it, I'd see in any of them are leaking but I'd be getting them cleaned & flow tested just to make sure that they're alright, but I can bet you at least one of them is stuffed. When I had an RB30E powered VL, it did that and that's what the problem was, all the injectors were leaking and needed to be replaced. I had a hard starting when cold problem with my VY SS where it would run a bit rough for a few seconds, that was caused by blocked fuel injectors so I bought a new set as I didn't have the time to run around getting the old ones cleaned , plus I needed a car to drive.