smalmo1

iTrader: (2)

Apologies in advance for the long winded post but I want to give as much detail as possible.

2006 350Z, 6 speed, 70,000 kms. Ran small nitrous shot and bolt-ons last year (310 whp). Tuned with UpRev. Car ran great.

Installed a BP turbo kit over the winter along with a CJM Stage 0 RFS. Got a base map from Vince at RT so I would have a relatively safe start point for a tune. BP kit includes Walbro 255 pump and 550cc injectors. Set idle fuel pressure to 45 psi as Vince recommended.

First start- idled fine and settled in to damn near perfect AFR, 14.7ish as read by a new Zeitronix ZT2 Wideband. Sounded like there was an exhaust leak but I took it out for a short drive. Under light throttle the AFR came down to low 13's. Went WOT and AFR went to low-mid 12's but the car fell on its face. I was at almost 4k rpm when I floored it and only hit 1.8 psi of boost. I got out of it right away because it didn't sound or feel good. Light smoke from the exhaust as well. Drove it home and put it back on stands to work on it.

Exhaust leak was coming from the drivers side manifold so I changed the gasket and that fixed it. Still didn't sound right. Pulled the codes on my DashDAQ and found the O2 heater codes I expected to see but also P0300 for random/multiple misfire. Checked for vac leaks and couldn't find any, checked the plugs and didn't find any issues, new TR6 copper plugs gapped to .032. Cleared the code and dropped the car, thinking it might have thrown the code when I was setting the idle fuel pressure. Having never heard a boosted VQ I thought I might just not be used to it. Left the car for a day.

Second drive - started the car and idle was fine, AFR was fine. Exhaust leak fixed it sounded much better but still sounded like a misfire to me. No code after some low throttle so went WOT again. Same result, AFR dropped to low 12's but wouldn't build boost and stuttered. Light smoke again. back to the garage to scratch head. P0300 code throws again.

Third drive - start car and AFR pegs the gauge at 21. WTF? light throttle brings it down slightly but not much. I pulled out of the driveway and back in about 30 seconds later. Shut car down. I can hear the fuel pump running with the key on, start car, fuel pressure is steady, AFR starts at 15 and rapidly climbs to peg the gauge again within seconds. P0300 is now thrown at idle.

I checked the plugs again, now some are whitish from running lean and some are sooty, smell like gas and have a little white on the electrode and ground strap. I run the cylinder power test with Cipher and shutting down 2,5 and 6 the car almost stalls out. 1,3 and 4 have little effect.

The smoke I found is from oil getting past the turbo. There were oil drips on the exhaust vband and pulling the lower intercooler pipe resulted in oil running out. Luckily there is no oil residue in the intercooler pipe attached to the intercooler so the lack of boost prevented oil from getting that far and getting into the intercooler. No idea why oil is going through, it is a brand new 6266 turbo and the scavenge pump is running properly.

Coles notes:
What would cause the car to not build boost and stutter on acceleration? Most likely the misfire issue.

What would cause the multiple misfire issue? Plugs are brand new. Coil packs were all good when it was parked last year. AFR was fine initially so injectors should not be an issue. Idle vac reading is -15 and I couldn't find any leaks. Fuel pressure is steady so fuel pump shouldn't be a concern. I was hoping I had switched coil pack plugs but that wasn't the case and the cylinder power test indicating that 1,3 and 4 are the cylinders with issues eliminates that possibility.

What would cause the lean issue from parking it one day and starting it the next when fuel pressure is still steady?


Again, sorry for the novel above and any ideas on what to do next would be greatly appreciated. Before this winter I had only changed fluids, plugs and belts so I am in over my head at this stage. I would take the car to a shop but there are no VQ specialists in the area that I am aware of and a dealer would be a waste of time with the turbo kit on it.

jerryd87

iTrader: (4)

what color smoke? also did you hook up the lines correctly? my buddy screwed up helping me and hooked intake/throttle body heater line to a vacuum port and sent all the coolant into the engine >.< because it definitly sounds like the issue i was having till i noticed what he did(except i never took it for a test drive.) could also mayby be a blown head gasket the oil is kind of interesting i havnt had that problem and not sure what it could be unless mayby incorrect clocking of the resevore?

binder

iTrader: (8)

ok first things first. STOP BOOSTING THE CAR! vince have you a START tune not a boost tune. It's an untuned car and you are basically destroying it. that is the stupidest thing you could ever do. just knock it off now before you destroy your car.


Now, the oil. You have not properly primed your oil pump and the oil is pushing past the rings on the turbo. Drop the oil pump and you need to pour quite a bit of oil inside the fitting that goes into the oil pump. It takes quite a bit. The gears need a good amount of oil to start a solid seal. Once you get it sealed it will work perfectly. After you get a good amount of oil in it when you turn the key on and the pump is running you can test it by putting your finger over the input fitting and it will have suction on it.

next, clean out all your cold side piping. Remove it all and remove the intercooler and clean it out. This should fix almost all your problems. The oil being sucked into your engine is probably causing the car to misfire.

about the a/f.....leave the car alone once it's running again and take it straight to a tuner. Do not just joy ride on a quick base tune that is only designed to drive you to the tuner.

lack of boost is probably due to the exhaust leaks or the fact that it's not tuned properly and misfiring. Hard to tell but you have to get the oil pump primed before anything else. I would get under the car while it's running and check the 3 bolt flanges, then the vband at the cross over (people always install that wrong and have a huge leak there) then the 2 bolt flange. well, this is assuming you have a mid mount kit. The small vband should be tightened down BEFORE the 2 3 bolt flanges at the headers are tightened. If you don't do it that way the vband will not be flush and not seal causing a huge exhaust leak.

smalmo1

iTrader: (2)

Thanks for the help guys.

The throttle body coolant line is hooked up properly, interestingly the previous owner installed a valve on that line and had it shut. I found it when installing the kit and opened the valve. Don't see how that would cause any issues when hooked up tot he correct place though.

Vince instructed me to get some idle logs and part throttle logs and then if the AFR was ok to boost the car about halfway and send him the logs. We don't have any local UpRev tuners so I am following instructions from the best guy in the industry.

I will drop the scavenge pump and try filling it but I did follow the procedure in the manual by pulling the fuel pump fuse and cranking the engine to prime it.

For the exhaust leaks I did get under the car while running, that is how I found the manifold gasket leak and made sure there were no other leaks after I replaced the gasket.

I have already removed lower intercooler pipes and cleaned them, there was 0 oil residue in the pipe attached to the intercooler. I will manually prime the pump and change plugs.


The most concerning issue is the AFR being fine one day and pegged lean the next, any thoughts on possible causes?

binder

iTrader: (8)

leave it closed. It just runs hot coolant through the throttle body to help heat it up faster in the winter which means the throttle body will be heated to the coolant temp in the summer thus slightly increasing IATs. I removed all that stuff completely and don't have issues in the winter. It's only an emissions thing. faster engine warm up=better emissions.

about halfway doesn't mean WOT. 12's a/f is a fast way to blow the engine on pumpgas. Press the gas pedal down to slowly bring it into a little boost is "about halfway". So you'll see 1 or 2 psi and watch the a/f. If in the 11's then you can give a little more throttle the next time and do like 3psi and so forth. Vince is one of my favorite tuners to deal with. Very smart and he has a very easy to understand way of doing things. I love his "keep it simple" approach.
i did that probably 20 times over the course of a week and still wouldn't prime. You have to manually fill it. That's the only way it worked for me. With the oil line running up and over the turbo the pump has ZERO vacuum until it gets oil inside of it. So no matter how much you crank the engine the oil will never build up enough to make it over the turbo and into the pump to prime the pump. Instead the oil builds and presses out of the rings (seals) on the turbo. [/quote]
probably the misfires causing the no boost or the high a/f.
I wouldnt worry about it until the other things are fixed. With multiple things going on it's too hard to determine. One step at a time will make things more clear.

i'm not on the web very often so if you need help you can email me. Email goes straight to my phone.

Jeff

Glex25

iTrader: (11)

I had a car come to me with multiple misfire and found that the wiring for the injectors were on backwards. The banks were incorrect. I would also check the coil wiring and did you change the spark plugs to one step colder

binder

iTrader: (8)

not needed for stock block power and plug heat range wouldn't cause a misfire unless it was too cold to properly ignite the charge.

smalmo1

iTrader: (2)

I'm 99% sure the injectors were wired properly. I don't think it would make sense to have 2 cylinders on one bank and one cylinder on the other bank not firing properly if that was the case.

Plugs are one step colder and gapped to .032. Coil wiring is correct.

I closed the TB coolant valve.

I dropped the scavenge pump and got a tiny bit of oil into it before it was full but it does sound much better now so hopefully the oil issue is solved.

I'm going to pull the intake manifold for the 23817390 time and double check the injectors, change plugs and swap the coils from 2,5 and 6 to 1,3 and 4 and run the cylinder power test again to see if it follows the coils.

binder

iTrader: (8)

ya, if you noticed a change in the sound of the oil pump then it probably created a good seal. Should be fixed.

When i got a new one to install due to a problem with the last one I loaded it up with quite a bit of oil before installing it. Never had the issue i had the first time.

Eno

iTrader: (1)

I have 100% confidence in what you're saying binder so don't take this the wrong way but everyone who has ever talked to me in here or in driver or at the shop always said FI= 1 step colder plugs.

Was I misunderstanding? What's the crossover point when they are needed versus not needed?

Sorry if ot.

binder

iTrader: (8)

no problem.

What is happening is everyone is blindly following a myth rule without actually understanding spark plugs. With motorcycle racing and tuning we use spark plugs for tuning a bike heavily.

The heat rating is basically how long and hot hot the electrode will get. Lower number means it heats up faster and will remain hotter temperature. When dealing with a low octane fuel (say 87) that hot tip could be hot enough to cause the fuel to ignite before the actual spark charge is sent to the combustion chamber. If that is the case then a colder range must be used. The key here is getting a plug that is hot enough to cause proper burn but not hot enough to cause it to pre-ignite.

Now with FI more fuel is used and the air is compressed into the combustion chamber giving it more energy and heat. Due to the added fuel it will also be slightly easier to ignite therefore a colder heat range plug might be warranted. That all varies based on amount of fuel. As power levels go up the fuel being used goes up as well. With a stock block power level tuned properly a stock heat range plug is not hot enough to cause pre-ignition. Using a 1 step colder range for stock block power will work but if it's a daily driver and doing many starts per day it will waste fuel and could foul out sooner due to the lower heat produced and the extended time i takes to warm the electrode to proper temp upon starting. So for regular driving it would be out of the efficiency range of the plug. With a daily driver that spends 95% of its time in vac this really isn't a smart route. With a higher hp car you would need a lower heat range plug so it won't pre-ignite when driving WOT so a compromise must be made.

So anyways, no, the power produced from stock block does not need a 1 step colder plug. If someone says it needs it because they have seen detonation or whatever then they just didn't properly tune the car. That being said, 1 step colder plugs will work just fine at that power level but due to the majority of time spent in cruise the plugs will wear out faster. If anyone remembers 2 stroke dirtbikes they will understand. The engines produce high compression and a lot of power. When driven they need to be WOT almost all the time and the heat range is cold to prevent problems. Now take that same race bike and cruise around the track at low speed and it will foul a plug before you make one lap. That's the extreme example of plug heat requirements.

sorry for the off topic OP but i figured you would want to know as well.

Eno

iTrader: (1)

Thanks binder- you've really got me thinking hard now about the 9s I invested in when I rebuilt. (had the rebuild). Seems to me the way I understood it was that it was protection against preignition and was "safer" while maintaining the needs of the increased power- similar in a way to water meth that can add safety or eradicate it if not used properly.

Fouling the plugs sooner by not driving hard enough was certainly never put on the table but you've really got me thinking about my realistic driving Tendencies and what would be best for the engine.

Sorry op- you have the floor again!

350z006

iTrader: (79)

Good write up! One more question before we close the book on this topic (sorry OP, lol)

Is there a good threshold point hp wise to go to a 2-step colder plugs with the Z?

On my current SC setup, I'm running 2-step colder...

djamps

iTrader: (1)

1-step colder isn't going to foul up -- just checked mine with 20k miles, they had some soot on them but no buildup at all. Only way you're gonna foul up is with a steaming turd tune or serious OC. They might not be 'needed' but the extra insurance can't hurt.

DaveJackson

iTrader: (5)

^20,000 miles. Isn't the maintenance interval much longer than that? Binder just said that they would foul more quickly if cruising a lot (as a daily driver would), but not immediately.

djamps

iTrader: (1)

Even so there was no abnormal buildup. Based on what I see around here most VQ's would be lucky to even go 20k mi F/I.

smalmo1

iTrader: (2)

Hey, I'm a noob and wondering which spark plugs are the best, is this the right thread....Lol

Update on my progress:

I decided to do a proper boost leak test before pulling apart the manifold again. I found a post recommending rubber PVC caps for the exhaust tips, a PVC cap for the intake and a tire valve stem in the cap so that's exactly what I used. I put the "fill" cap on the pipe right off the turbo and pressurized the system to 2.5 psi. Found 3 coupler leaks that needed t bolts tightened but no manifold leaks. Is there any way to tell if the lower manifold gasket is leaking?

I'm going to do another test at 10 psi to make sure I didnt miss any leaks and then I'll start it and see if anything changed with the AFR before I rip into the injectors/coils/plugs.

On a bad note, the scavenge pump sounded crappy/grindy again. With the scavenge pump running while the car is off would it start drawing air somehow and lose its vacuum?


I'll keep updating as I find/fix things and if anyone has an idea for something to check please let me know. No suggestion is too obvious or stupid, I have zero experience with FI and only know what I've learned reading and searching the forums.

Thanks.

Boosted Performance

iTrader: (14)

This was covered...the pump will be loud when there is no oil in it. Once oil enteres the pump gears it will silence it, as it pulls vacuum from the turbo/oil reservoir.

These pumps are $400 each,well built, and are all tested before being sent out. Poure some oil in the in port, and see how the sound changes.

binder

iTrader: (8)

2 step I think would be too cold IMHO. I'm running 650hp on 1 step colder and haven't had a single problem with pre-ignition. I was mid 500's on pumpgas with the same heat range but i'm on e85 now so that will help with the combustion temps. IIRC Thom was running in the 800's on race gas with 1 step colder plugs. I do think that at this range 2 steps colder would be the best option but since he drove his car a considerable amount the 1 step colder would work. There really isn't a set requirement but i wouldn't even consider 2 step colder until over 600hp. After that point it would be a case by case basis of checking the plugs to see if there is any preignition.

I wouldn't go out and change them if you already have them in but depending your hp level on the s/c I would probably use 1 step colder on the next plug change if you drive your car a lot.

I didn't say it would just foul. It will have tendency to wear out sooner. Every engine is different. Putting parts on you don't need isn't really "insurance". Colder plugs will not prevent detonation from a bad tune or a bad batch of gas so it's really not protecting anything. It's a matter of matching the proper heat range verses just going colder to try to prevent knock or something. Putting a 5 bar map sensor in a 10psi car or running 385 wide tires on a 400hp car is more than enough but doesn't help by using it. Not really the same thing since going too cold of a plug can actually cause problems when running big tires can't. Basically you match it up properly and don't try to use a plug to make the car safe (since it won't make anything safer by going colder than needed).

thanks

I would tun the boost up to at least the boost you are running when you check it. Sometimes the leaks won't start until a certain PSI. For the injectors or manifold leaks just get up real close and listen when it's pressurized. You can use a piece of rubber hose and put it up to your ear while you stick it down by the manifold and injectors to listen better.

as for the oil pump as sasha says above: just unbolt the pump, take off the input fitting and get a small funnel (i used a syringe) and continue to put more and more oil into the input port. I used a bunch in there. Then turn the pump on and keep putting more oil into it. The pump will get quieter when the oil is in it. Once it gets an oil seal it will not lose it. This is a gear pump so it will never be quiet but it will quiet down when it gets a seal.

smalmo1

iTrader: (2)

Latest update:

Vince called me and apologized for taking a while to get back to me with a revised map while he was out at drift events for most of May. Absolutely a stand-up guy, here he's doing me a favor and apologizing for not doing it fast enough! I felt much better after talking to him and this car may still end up on a truck headed to RT for Vince to tune in person.

I leak tested at higher pressure and found a whisper of a leak at the crossover pipe vband. It is as tight as it will go so I guess I'll try to heat cycle a few times and tighten. If that doesn't work I'll loosen off the manifold bolts and try tightening it again. Really don't want to mess around with the manifold bolts again. Vac reading is still -15 at idle. Using the higher pressure I could hear a dripping sound somewhere inside the engine, no idea what that would be, pressurizing the crank case maybe? Couldn't hear any pressure coming from the PCV or the dipstick.

Sasha, the oil pump sounded terrible and I had oil in my intercooler pipe and exhaust. After using Jeff's method to fill it sounded much better. Before I blew oil past the seals again I just wanted to make sure there was no possible way to lose the vacuum again as the pump sounded exactly the way it did initially. Started it last night and the sound smoothed out so oil concerns are set aside for now. If I have more oil in the pipes I'll have to revisit the issue and assume the turbo seals are no good.

The revised tune brought idle AFR down to 17 on the Zeitronix, HOWEVER, the Cipher logs with the oem widebands showed Bank 1 in the high 20's and Bank 2 in the 14's. Sent the log to Vince for review.

I was going to get the manifold off last night but with Vince getting me the revised map I wanted to get him another set of logs so tonight will be the start of manifold removal/plugs/coils/injectors troubleshooting.