This is interesting and i wanted to see if anyone can help with this . As far as I know of their have been 4 Blown engines here on the org recently. These engine all have several constants that are a little too coincidental. Once i post these constants maybe we can start figuring out what the problem may be.

The cars i am speaking of are:
Redmax
Ben Blanco
Tilleys99
PmpLuxCEO


Contants
All 99's
All Cali Spec
All Auto's
All blew at around 120 to 130 mph (end of 3rd gear)
All of them Seem to be at least the head gasket, but may not have been, the oil has shot out of the exhaust.

We know nissan changed some things especially in the 99.5's but what did they change in the engines?

Please post if you have blown an engine of the same or different year and wheteher or not you are auto , also does anyone have any ideas?

I just got off the phone with the people who are working on my car and they said i broke a piston, spun a main bearing # 3 spun 2 rod bearings #4 and 6 and scratched the block. so I now need a whole new block

 

My car is actually a fed-spec Infiniti I30, I don't think engine-wise they changed anything from the maxima and the I30.

When the parts for my car come in, I'll finally be able to diagnose what went wrong when they pull out the engine. I'll keep you all updated.

 

this is scaring me.......

99.5 cali spec sc 3.125 pulley but i have never pulled my car hard up a hill before. i have peged my egt at 1380 @ ~90psi of fuel pressure i do fuel injector cleanings every 3 months on a few top speed runs .

my egt probe is behind the o2 sensor on the flat of my y pipe.

 

"All blew at around 120 to 130 mph (end of 3rd gear)"

Hmmmn....fuel cut maybe?

Take LOTS of pictures of the damaged piston(s) please.

 

exactly my thoughts.... but if you run an auto to fuel cut in 3rd than you were kinda asking for it unfortunately....you should have easily known to let off by then

 

then mine should have blown 4 or 5 times. I have hit the limiter in 2nd and 3rd more times than I want to count, but I am a 97 NON cali spec.

But you MAY be correct.

I am NOT 100% on exactly what the swirl valves do, I think they keep emissons down during low rpm... could those have comme into play?

What about fuel pumps?

What FMU disk was everyone running? ALL the same?

Spark plug gap?

Just trying ot help

 

swirl control valves should be wide open nearing redline... if they were closed or malfunctioning, getting up to those speeds would be very tough...

plus, they would only constrict the air going in to the cylinders... you would run rich probably if they stayed closed...

 

i had the solenoid pluged for the swirler for a while. capped of the vaccum line.

i have one step colder ngk coppers.

still running the 6:1 fuel disk. walbaro fuel pump with sard fpr.

spark plug gapped to .34 i believe or if i can remember right.

 

Maybe you should also talk about what kind of boost/fuel accessories all of these cars were running as well.

 

Having the fuel cut doesn't 100% guarantee a blown engine, just like a missed shift from 3rd-to-2nd with 9000+rpm doesn't.

 

Your correct, I was just thinking that if 1/4 of the people who miss shifts or hit the rev. limiter blew the motor that number would still be high.

And again you may be correct.. I am GUESSING. ( and whoring )

I wish I knew more info about the differences between the 98 and 99/99.5.. that way I may be able to help more

 

the major difference is the swerler on the lower intake plenum.

different sensors and stuff but basically thats it. i talked to one of the mechanics at the dealer i work at.

 

Same here.

 

corey....Ben had a 97.

--Paul

 

One of the engines you mention, the guy was not using, a boost gauge and a EGT gauge. Let alone I doubt the person had any clue what boosting consists of. More air more fuel. I am not a fuel pressure expert but with a 3.125 pulley it is required for you to go with a 8:1 FMU disk that size disk will keep you rich from 3-66K without a MEVI. Also the person did not post if the aux fuel pump was hooked up properly to flow more fuel. Even the Walbro makes a distinct noise in your fuel tank. I have not seen a post how is it suppose to sound.



For cali spec maximas like yours I believe the header has a precats, at least thats what I can understand from what I read. If you do have those precats rip them off and replace them with normal headers for a better flow of exhaust gases. Also what type of boost controller are you using? <---------- not a turbo guy either but I believe the manual boost controller may spike, if I am wrong one of you turbo goons help me out here if I am wrong, at least thats what I saw happen to one of my friends maxima but no Kaboom and he runs it up to 140MPH pretty of often.

 

i wonder where qnpark is ??

he has hal's turbo kit and has blown like 3motors and 2 tranny's
no joking around, its 4 real.



man what are you guys doin, beating the living crap outta your cars???

 

10 Characters...

 

Nope, this is a big issue for me because i never really got a chance to drive my car with the turbo on it. I had myy car tuned one day and it blew the next day. I wish i got a chance to beat the hell out of my car, and it only has 70000 highway miles on it

I just spoke to a guy a jwt and he said the issue is probably that with stock fuel pump the car had too much air and not enough fuel and detonated. but I dunno, oh well more money more money moer money. I wish i knew how to build engines instead of spending all of this money to have one built

 

That would have shown up on the dyno runs, though. What afr's were you seeing during the runs?

 

Hey Redmax,

Your car is the one featured in custommaxima.com's site, right? I noticed there was no recirculation tube running from the bov to the compressor inlet, even though you have a draw through setup.

Did your car idle okay? Did it show any tendency to stumble after revving it in neutral?

 

I think i remember a thread awhile back saying the 99 had a variable voltage going to the fuel pump? I wired mine direct to the ignition.

 

What FMU is everyone running and FP?
Mine was a 2000 auto w/ 3.125" pulley when I blew.

 

regular vortech fmu with 6:1 hasne't blown up yet

 

the same thing with QNPARK, he put his custom built m0tor in and took the suka out and BBBBBOOOOM!
but i think his is a 97 or 98 and its a 5speed.

 

Yes it is the car on their sit, no the car does not have a recirc valve but the afc has a feature in it so that the car does not shut down after is blows off. the car did idle ok. I can post the air fuel dyno later which i think sucks but the tuner said the a/f was ok.

 

did they "initiate" this feature when they tuned it??

 

I dont understand what you mean by "initiate" but here are my Dyno's



Flame on!!!

 

the feature you speak of is called "Deceleration feature" it is in the SAFC settings menu the last one on the very bottom, if his car was stalling a good way to stop it is by tightening the BOV, it may not stall as much.

Redmax looking at your AF ratio chart looks alright and starts to go up @ 5K.

What PSI is this?

 

8:1 with 2.87. have seen >110psi on my FP gauge @ 10psi.

 

Can you attach the files or email them to IceY2K1@maxima.org?

I'd like to play around with that run viewer.

Thanks!

 

these runs are at 6 psi

 

90% time when someone blows an engine...it's lack of fuel.

 

Is that a Vortec FMU

 

yup. an 8:1 and I dunno why it gives me more than what I am supposed to get.

 

Herr's my thought....I think that the Vortec FMU is causing us to run lean at WOT and causing detonation. Regardless of the size of the disc. No one has blown with a Cartec (that I know of). What do you think of that.

 

Hmmmmmmmmmm

 

Interestingly enough I think hal has switched engines a couple times himself just ask him about it. He put a 99 motor in at one point and had serious problems, then he put the 96 back in and no issues. Per say perhaps it was a problem with that 99 motor already but.......................very interesting..and doesnt help that I have a 99..haha.

 

Aren't we missing the obvious? The higher the gear, the longer you stay in the power band, the longer you stay under boost, the longer you stay under boost the easier it is for slightly bad problems to become serious problems (detonation). Higher speed runs almost always spell disaster for poorly tuned setups.

The reason these engines blew were because of poor FMUs. Systems (example : Vortec) that just dump a ton of fuel in an effort to saturate the combustion chamber and cool it, are power sapping and push the fuel pump too hard. If you're going to run boost, invest in a good and reliable setup and tune it for every situation through the use a hours of dyno tuning. Everyone wants to run boost, but rarely do they want to invest in the right tuning and safeguards.


Dave

 

Why are people even investigating their blown motors? The amount of money spent on teardown is more expensive than a junkyard motor plus I wouldn't even trust Nissan to be able to reassemble a VQ the right way. It's almost always better just to get a junkyard motor for $400-700 and invest in good fuel management. The VQ can hold some serious power, you just need to tune it right.


Dave

 

would it be possible that one or two of the fuel injectors hicuped or maybe failed during these runs?????? is that the cause of the blown engines.