Real Fiero Tech

Try that.

Anyone know how the ignition is controlled on that thing? I assume the ECM doesn't just ground "Cylinder X/Y Control" to fire X/Y since then it'd have to be doing wasted spark..

Series8217 wrote:Anyone know how the ignition is controlled on that thing? I assume the ECM doesn't just ground "Cylinder X/Y Control" to fire X/Y since then it'd have to be doing wasted spark..

It's individual cylinder control, just like the LS1. I combined the pinouts of the coilpacks for simplicity. There are two - one for the even and odd bank. All cylinders have their own control pin on the PCM. The "ignition module" is the PCM. Unlike the LS1 coils which have some control circuitry onboard each coilpack, I am pretty sure there is nothing but coils on the N*. I could be wrong.

I guess I am too late since you have already looked at the injectors, but the BS3 fires the injectors backwards, all stock ECM's have a constant 12V at the injector, and the ECM grounds the ground wire to fire the injector, well, the BS3 sends power to the injector, I think it said it make it more accurate or something, but just so you know, if you check the wiring, it should have a constant ground at one of the 2 wires on every injector, and pulse a 12V signal when it fires.

I am thinking you may have a plug boot problem, or a coilpack gone out. Your N* probably has the same plug boots as my Quad 4 had, with the little spring in the boot to connect the coil to the plug, they could be corroded, or not making a good connection. When you do take it off and get the plugs firing, put di-electric grease on every connection down there, that will seal out alot of moisture.

Ben, what are you doing this weekend? You should come out and play some Halo 3 or Forza. We can look at some wiring while you are here lol.

I'll be dropping the ass end of my cradle to pull that coil pack to see what is going on.

Did you win yet?

Been working steady and had to go to my home town for Easter last weekend. I'm off this weekend but had my wisdom teeth pulled this morning so I'm in no mood to play with my car.

I'm on a week off so I'll find some time to work on it.

It's snowing here, not much motivation to work on the car. Wish I was in Florida right about now. :blah5:

Finally have some good weather and spare time so I worked on the fiero this morning. I lowered the rear of the cradle and pulled the front coil pack. It was much easier than I thought it would be.

First thing I did was put in 2 new spark plugs where there was no ignition. The old plugs were quite gummed with fuel as you could imagine. I pulled the boots and took out the springs, they looked ok. Took the coil and sanded the tips. There was a bit of rust on them so I got rid of it.

I swapped coil packs front and back, put it all back together, fired it up and..... still missing.

I started pulling injector plugs, first on the known 2 dead cylinders and much to my surprise it started stumbling! I pulled the other dead one and more stumbling! I was pretty excited. I pulled the injector plugs on the swapped coil and there was no change. So I have narrowed the problem to a bad coil pack. I am very relieved it is such a simple fix.

So Monday morning I will start calling around and get a new coil pack. :afrocool:

Yay, that is good news. :thumbleft:

Called everywhere today for a coil pack. Only place that had one was in Calgary, 5 hours away. It was a long boring road trip.

Got home at 10:20pm, installed the coil pack and took the car up the road. It had even less power than before. :scratch: Turned around and half way home I remembered that I forgot to plug in the coil... dumbass!

Plug it in and wow. So that's what a N* fiero is supposed to feel like!

I no longer have to rev the motor after pushing in the clutch to keep it from stalling. I no longer have the severe "clutch chattering" which in hindsight was the dead spots in the firing order. It's civil to drive!

Already in contact with the dyno operator to finish tuning the engine. :thumbleft:

crzyone wrote:Plug it in and wow. So that's what a N* fiero is supposed to feel like!

Sounds like the first time I got mine to run without torque reduction.
"Holy Shit!"

Good job!

Wheeeeeeeeeee! :thumbleft:

whipped wrote:You SHOULD be able to hit 290whp. With your BS3 problems, ehh... probably 230. :la:

g/l :thumbleft:

I need to come up there and have a spin in it. Faster than the Skyline?

That is great news Levi!!

At this point in my schedual I am going to have to make it an after hours job due to heavy bookings through June.

Let me know you available times for the next month including saturdays and sundays.... I will need to squeeze it in.

Thanks,

Martin

AFI Performance wrote on 04-29-2008 12:13 AM:
Please Don't assume that the car is running healthy because it feels less qrappy with the new coil. That engine is a really easy one to hurt, and my tune is out to lunch with a cylinder being down like it was. Take it easy on it man!!!

Martin

I'm going to baby the car now until it hits the dyno. It's pretty cool that he is willing to tune after hours to get me back on the road.

Ben, it's hard to tell if it is faster than the skyline. Both put you back in the seat but the fiero feels more violent. It has instant torque were as the skyline has such a smooth power band. After tuning I have no doubt the fiero will be faster in the 1/4 mile... But with the mods I am doing to the GTR as I replace the motor should also make it a high 12 second car. It's going to be really tough deciding which car I want to keep.

That's good advice!

good news!!! awesome. if anything, you will have a good running and properly tuned fiero.

A very interesting thread! Will, I don't agree with your (4/3)*175=233, as power is being used to pump the dead cylinders. I'd say more like 175=185=247. Or am I missing something?

Those pistons that were not firing were taking up huge power.

How much power do you think it would take to power an air compressor that spins at 6000rpm and puts out 200psi? That is a shit load of parasitic loss on 2 pistons. I bet they were sucking up 25+hp easy.

So, instead of sucking up 25+hp now they will be putting out around 70-75hp. I bet my base run will be 250+whp.

With a good tune and everything running 100% you should see a lot more than that. 290whp.

283WHP is my new guess.