mjk

iTrader: (1)

I was racing one of those older camaros RS' v8s and my tires were already pretty gone so I was spinning alot and started bouncing off the redline. The whole time I was spraying... Anyway, I always thought that you cant blow an engine doing that if your running a wet kit...

I bounced 3-4 times. then in 4th gear ( not spinning anymore) I felt a jerk, and then a loss of power. After that everything was fine, so I thought.

Soon I realized that I had a major loss of power and that the seemed to be skipping beats.. Anyway I pulled the cods today and got a multi cylinder misfire..

Questions:
could that be cause by...
1. a blown maf?
2. plugs gone bad because of the bounce?
3. nasty detonation and will I be needing a new engine?

Thanks guys/gals

CalsonicSE

iTrader: (3)

check your plugs first and then report back

mtrai760

iTrader: (19)

You may have made a pretty expensive assumption. Bouncing off the rev limiter while spraying = One of the things that happens when you hit the rev limiter are fuel cutoff, which means you would have continued to get a load of nitrous, without any fuel, which could mean some pretty serious detonation. That is why it is advised to use a window switch, to control in what RPM range the nitrous will spray, and keep your engine safe. Like said above, the next step is to check your plugs. Then I would do a compression test.

CalsonicSE

iTrader: (3)

I think he assumed there would be no problems because the wet kit nozzle is supposed to provide proper fuel/nitrous mixture. When you hit fuel cutoff, do you know whether the fuel pump shuts off or do the injectors shut off? I think it's the latter, but if it's the former, then that would help explain detonation cuz then the nozzle would no longer be mixing any fuel with the nitrous.

mtrai760

iTrader: (19)

The injectors shut off. Even with a wet kit, the fuel put out by the nozzle is only to supplement the fuel from the injectors. It is not enough on its own to provide the proper nitrous/fuel ratio. It would be like running a dry kit on low fuel pressure. Only way to know for sure is to pull the plugs and check compression.

CalsonicSE

iTrader: (3)

Interesting. I thought the additional fuel from wet kit nozzle was supposed to provide a proper mixture. For argument's sake & hypothetically speaking, if X amount of fuel is supplied by the injectors to maintain 12.5 a/f ratio at NA WOT, I thought the additional Y amount of fuel supplied by wet nozzle plus the nitrous should keep you at 12.5 a/f ratio when spraying (at WOT of course). I don't think the injectors provide any additional fuel when spraying, so the fuel/nitrous combo from the nozzle should be an optimum mix if a/f ratio stays the same, right? The conclusion I make from what you are saying is that when spraying a wet kit, a/f ratio will always be leaner?

Oh well what do I know? I've been running a dry kit from day 1.

mtrai760

iTrader: (19)

The only difference between a wet and dry kit is the way the extra fuel is delivered. On a dry kit, your fuel pressure is bumped up, forcing the injectors to provide the extra fuel. On a wet kit, that extra fuel is spraying in with the nitrous, with no increase in fuel pressure. In either instance, your 'normal' amount of fuel is still required, normal being the fuel that would normally come from the fuel injectors at 45 psi under full throttle. On a dry kit, it would be like running a 100 shot on 85 psi, then pulling 45 psi away, leaving you with only 40psi of fuel pressure, but a 100 shot still flowing into the cylinders. This of course is not possible with a dry kit, because you either have fuel, or you don't. But with a wet kit, you can still spray fuel and nitrous together, you just will not have enough fuel for the amount of nitrous your running. The extra fuel is only supplemental, not enough on its own. In either case, you can run lean and break a ring, piston, rod, etc....

CalsonicSE

iTrader: (3)

OOPS, AFTER THINKING ABOUT THE ABOVE STATEMENTS AND CONTEMPLATING WHAT I ALREADY KNEW IN FIRST PLACE, I REALIZED I LEFT OUT AN IMPORTANT FACTOR i.e. the amount of air normally sucked into the cylinders.

WET KIT:
1) NA WOT: A amount of air + X fuel supplied by injectors = 12.5 a/f ratio
2) spraying WOT: (A amount of air + X fuel supplied by injectors) + (B amount of nitrous + Y amount of fuel supplied by nozzle) = 12.5 a/f ratio
3) spraying WOT at fuel injector cutoff: A amount of air + B amount of nitrous + Y amount of fuel supplied by nozzle = LEAN

Hehe, I must've been smoking something this morning. =P Anyway, thanks Matt. Technically speaking, having your injectors cut out on a wet kit is "better" than having your injectors cut out on a dry kit. Still bad regardless.

Although, I guess I could still say the fuel provided by the wet nozzle alone would provide an optimal mix (IF there was an engine designed where the ONLY gas being burned in the cylinders was the nitrous from the nozzle.)

SonicDust187

iTrader: (11)

Doesn't the ecu run 13.0-13.5 NA WOT?

kcryan

iTrader: (1)

Plugs............

CalsonicSE

iTrader: (3)

The a/f ratios I posted were hypothetical.

mjk

iTrader: (1)

i have the NX with genX, and I believe thoguh not sure, that if for some reason it detects that the fuel i not flowing that it would shut off the nitrous also.... I'll check out the plugs tomorrow morning

mtrai760

iTrader: (19)

That's the thing, the fuel WOULD still be flowing, just not through the injectors. The maxima has a return fuel system, any fuel not used as it goes past the injectors is returned to the fuel tank. Fuel pressure would be maintained throughout, but you would not be getting any fuel through your injectors, only through your NX nozzle, which means you would have run really lean.

szakal

BTW he was running a 50 shot. (was with him when it happened)

C MAX

iTrader: (4)

sounds like you detonated, checked the plugs for oil or a blown tip. the same thing happened to me, i have a auto and i accidentally hit the shifter into second causing me to bounce off the rev. it was for a second but the end result was a blown motor, hope this is not your case.

mjk

iTrader: (1)

Alright so this is what happened. I was going to check the plugs, but I found some cheap bosch (for a max) laying around so I swaped them, now I also disconnected the batt for about 15-30 minutes.

At first nothing was different. I drove it around a little, it seemed stronger but stil nothing changed at first. Then I pulled over and decided to press on the cables that that go into the maf plug, then couple other plastic plugs... got in agani, the car felt better, maybe because I turned it off though... then for a second it ran fine... couple minutes later again... by the time I got home it ran fine more than bad.. still had a bog from time to time.. I'll see after I wake up ( i work the 3rd shift), hopefully its fixed ..

... 75shot++ hopefully this spring lol...

Thanks for everyones input so far.. hopefully it'll be enough, I'll know for sure as I drive and make sure its back to its smooth self.. 84k miles on her though...

C MAX

iTrader: (4)

also check for a loose vacuum hose, i hear detonation sometimes blow them off.

mjk

iTrader: (1)

okay, i drove to and from work and it looks like im still in a bad shape.. CMAX, dont laugh but i dont know where the vacuum hose is, nor what it does

C MAX

iTrader: (4)

sounds like me lol, they are located on the piping going into the throttlebody, should be one from each bank and also under the throttlebody where they all connect sometimes pops off
heres a diagraph if it helps







[/QUOTE]

mjk

iTrader: (1)

oh man, nice. i owe u one. thanks

mjk

iTrader: (1)

looks like one of the tubes leads to no where. It basically ends just sticking out into the bay... I'll look exacrly at what it is, when I print these..

mjk

iTrader: (1)

ok so I printed it checkd against it and I cant verify waht I was looknig at.. one of the duiagrams, the one that show a top view of the bay doesnt look like the max I have. throttle lines/wires are in a different position.

Anyway, The tube I am trying to to trace, is short rubber, then becomes metal and is screwed onto the manifold. It sits right under and next to the throttle lines... D0 you have any clue to what it is and where it should terminate... For the time being I attached it to a semi logical location... ll see if I was right, but that part I atatched it to does not have an inlet for anything maybe its just a senso or something...

C MAX

iTrader: (4)

on autos you will have a hose just sitting therefor the transmission to breath other than that all hoses have a connection. check the two that come from the right and left banks make sure they are attached to the piping somehow and then make sure the hoses are connected to the spider under neath the throttlebody

mjk

iTrader: (1)

I'm going to give up on this for a few days.. it isnt looking good..

mtrai760

iTrader: (19)

Have you done a compression test yet? That will tell you a lot right there. Looking for loose hoses sound more like wishful thinking.

mjk

iTrader: (1)

Hmm, will the compresion test be corerct even if the maf is malfunctioning? The lose hoses are a maze, I just cant deal with it, I tried... I'm thinknig now about replacing, or testing the maf, but i dont know how to test it without swapping it... Again if I do a compression test and the afr is bad because of the maf, will the comp test still be accurate?? thanks

I listened to 2f2f soundtrack, and now I want my car to work again

mtrai760

iTrader: (19)

Compression test has nothing to do with your MAF

mjk

iTrader: (1)

okay, I'll try to get one todaty. thnaks =]

mjk

iTrader: (1)

okay, I got the compession tester, do u know which size I should use for the max, there are like three?

I also noticed they ha a haynes guide to a maxima, which I might end up getting to help me check things eventually, if the compression comes out negative. Maybe itll help me find my way around the hoses, etc... I'm not very good at taht =/


Can I test the maf without taking it out?

CBass69187

iTrader: (4)

I wouldn't worry about the MAF right now. You want to use the adapter that is the same size your spark plugs (threaded part)

KRRZ350

iTrader: (29)

The ecu doesn't use the maf below a certain rpm, I'm not sure what that rpm is on our cars, but it's usually 2,500 or 3,000 rpm. So if the maf is blown your car will feel fine until you try accelerating past 3,000 rpm, it won't let it rev past it, it will feel almost like hitting rev-limiter at 3k.

Also, I'm assuming the compression tester came with instructions, but don't forget to kill the ignition system and have your assistant floor the pedal while he cranks it over.

CalsonicSE

iTrader: (3)

Our cars use the MAF at low RPMs as well. That's why if you have a bad MAF, your idle will usually be irratic.

mtrai760

iTrader: (19)

Stop spreading bad info. The ECU uses the MAF from the second you start the car. As far as the ignition system, you should have all of the spark plugs pulled anyway, and the fuel pump fuse removed, so it should not be an issue. Again, please stop spreading bad info, or I will delete your post.

mjk

iTrader: (1)

I'm betting that its a bad maf, since from time to time it runs fine... thanx for making sure i get the right info, I'll probably wait for saturday to get the compresion tested... Is there a write up on getting this done on a maxima? This will be the first time for me =]