Ok i was just wondering what types of fuel injection do the 3rd gens have??

 

they use carbs

 

Really







OH i guess you dont know then.

 

electronic fuel injection...

 

nope, I have no clue take a WILD guess what the "E" in VG30E stand for.....

 

thanks

 

Yeah, its electronic fuel injection. But I was surprised to find out that 3rd gen's don't have Multi port fuel injection. I think they would be much better off with the multi port set up

 

if they dont have multiport then what do you call what they have TBI? id be pretty pointless to have 6 injectors in 1 port now wouldnt it

 

What does the VG stand for? Very Good?

 

accualy autozone lists it to have sfi which i guess means sequetial fuel injection i wonder what the difference between sfi and mfi are

 

multiport and sequential are pretty much the same. it means it's set up so there is one injector per cylinder and it is usually set up to spray fuel right at the intake valve. http://auto.howstuffworks.com/fuel-injection1.htm

also, when they sequential it means the injectors opens right before the intake valve opens.

 

Just another question pertaining to the injection what does the VTEC stand for i know its the variable valve timing but what exactly does it do to increase power and why does it only kick in it 7000rpm's and not at 2000rpm ,just curious?

 

Yeah, and the VE is Very Excellent.

 

they are just engine idenification codes like any other motor(ie- SR, RB, etc.)

 

multiport is available in batchfire or sequential.
batchfire means all injectors fire at once
sequential means that they fir at different times

 

what cars use batchfire thats sound pretty pointless

 

yeah and a wallet killer as far as MPG....jeez all at once

 

they generally dont use the batchfire style anymore because they came out with sequential.

batchfire still has a slight advantage over carbs off-road because batchfire will continue to opperate at even the most extreme angles, where as a carb would not beable to supply the fuel. Some carbs are better than others at this though

 

The reason "batchfire" was around in many cars for a while was that it was simply cheaper to make and keep in mind, cost of computing power to sequentially fire each fuel injector was pretty expensive back in the old days (1980's). Remember, when the 3rd gens came out, a 286 PC was still the king and 1-2 MB of RAM on a computer was a lot.

V in a VG30E or VE30DE stands for V-engine configuration. D is for DOHC, the E (after 30) is electronic fuel injection and of course, 30 is 3.0L

VTEC stands for Variable valve Timing and lift Electronic Control. The whole idea behind VTEC (as well as VVTi, MIVEC, and other systems) is that it changes the valve timing (and valve lift in some of the systems) so that the engine can operate more efficiently at a given RPM range.

The fact is, when you're running at idle, you're sucking in small amount of air, injecting small amount of fuel. So you design the cam(s) so that the engine operates smoothly at idle. Now, rev that engine up to 5000-6000 RPM. You're gonna neec a lot more air and fuel to feed that engine. If your intake is big enough and you got the fuel pump/pressure and injectors to feed the beast, that part is set.

But to make the engine run more efficiently at 5000-6000 RPM, you should be opening your intake valve SOONER and hold it open for a LONGER amount of time so that your engine can take in more air and fuel than at idle. Same on the exhaust side to dump out the stuff.

Before VTEC, you pretty much had to compromise. You ground the cam so that you had decent idle, but still had a some power higher up. Or you ground the cam for HIGH RPM use or for street (lower RPM use) only.

So with Variable Valve timing systems like VTEC, you have two cam profiles (2 cams in one) so that you can have a smooth idle and a nice top-end for power.

One car that I remember using bachfire fuel injection was a VW Type-III (known more commonly as squarebacks and fastbacks) from the late 1960's. (Computing back then was in the dark ages) It didn't hardly make any more power than the standard carbs, but the key advantage was that when the engine was cold, it started right up and the driveability cold was also fairly decent compared to a carburetor.

I'm sure batch was used in other cars in the 70s and 80s, but most Japanese makes started with Sequential Multi-Port Fuel Injection from the beginning (a good thing). Maximas from day one (starting with the L24E) has the good stuff (aside from some fuel injector recalls in the 2nd gen).

 

thanks for all that info tom

 

Yeh seriously, that was a plateful, but I learned just about what I wanted to coming from this thread. Thanks.

 

Tom, check out www.nwmaxima.com

oh, and good info except for 286's were more of a 2nd gen thing, we had atleast 486's and pentium 75 and 90's by the time our cars were made hehehehe. Dont mind me, It's late

 

my parents are cheap and got me a 286 for cristmas back in 1990 i think it was a 1000$ with a 14" monitor and i think there were pentiums starting to come out but were still very expensive

 

1989 = first 486
1993= Pentium
For more info goto intel's history

 

As was said earlier, sequential fuel injection fires only the fuel injector that needs to be fired for the cylinder that needs the fuel. To do this properly the engine needs a camshaft position sensor. Engines without CAM sensors will not be sequential.

 

You guys know your computer history pretty well, that's for sure! I didn't know that the 486 was around since 89 (I was a Mac guy in the 80s). I bought a 486DX/33 in 1992 and it was still pretty hot stuff at the time. Thanks for the website info about intel.

 

Well technically, you should say cam and or crank angle sensors. But yeah, the ecu needs to know when each cylinder is in it's firing stroke in order to know when to pulse the injector.

To answer the original question. Nissan fuel injection is probably a derivative of the original Bosch design. As most auto makers use some some type of Bosch under license. I think maybe Ford is one of the few to use their own exclusive design

 

I've seen no sequential fuel injection system with just a crank sensor alone being used. But yes, an engine would have to have both a cam sensor and a crank sensor to be sequential.

 

VQ30 in the 4-gens don't have a sensor on the cam

 

question for me: i have the blue injectors. i know there are a few different color injectors for a vg. which ones are interchangeable with the blue?

 

Since it looked like no one mentioned it, I thought I would. When the VE is warming up the fuel injection is actually Simultaneous (or batch as its been called). Then when its warmed up, it switches over to Sequential. Its in the FSM if anyone wants to look.

 

Then I stand corrected..Thank you , sir.