Old...alternator...
Hmmm.
When they do age, they do get "noisy".
You might be onto something...

Yeah, swap it out to see if it helps.


-Ted

 

OMGWTFBBQ!!111!!!!

Its fixed

Can you believe it was the old alternator! Even though the alternator put out great voltage...it was producing major emi. Santiago and I tried removing the belt from the alternator and starting the car. Ignition interfernce still occured.

So, yesterday I simply removed the alternator from the car and started it. No ignition interfernce at all!

I put in my FD alternator....and she runs like a dream....it has never run so good


Thanks for you help!
James

 

Hoist one up at the bar!
Good job!



-Ted

 

im having the exact same problem.... im also running the relocation bracket.

HMMMMMMMMMMMMMM.....

i have been having charging problems for weeks...

looke like pineapple needs to address the ground issue with powdercoated brackets.

so grounding the frame of the alternator helped it charge like it should?

good thing i have a life time warrenty on my alternator. yay advance auto parts.

 

Yep, we're talking about DC current, so there needs to be a + and a -.
The + is the thick wire coming off the terminal stud on the alternator.
The two thin wires are for the exciter and the warning light.
So how else are you going to get - ?
Yep, the alternator grounds through the case...


-Ted

 

iv got the same problem. i just switched out my fuel pump and my secondarys and this prob just shows up, car dies when idleing some times and my acceleration is crap and i buck constantly. could it be a coincidence? ill try to take off my alternator, but i dont have a relocation bracket its just an alternator like its supposed to be. think it could still be my prob?

 

One way to find out...remove the alternator completly.

Just watch out what you do with the power wire from the alternator when you run it. It is a hot wire always.

James

 

Yep, well I found a double solution to this problem.

#1 a noisey alternator will mess up the trigger signals since the shielded wire runs over top of the engine kinda close to the alternator on most of our cars. I replaced mine with two different, known to be good units and the tach signal problems got %50 better. It still would cut out at a high, rapidly rising rpms.

#2 With new grounds to the engine, ecm, and body I measured the resistance of the shielding inside the crank sensor wiring to ground. It was about .2 ohms but I still had signal noise. Grounded the shielded wire at the motor end AND THE NOISE WENT AWAY! My tach is now rock steady even with the gains set at 2! No more fishy tach, missfires, hesitation, etc. Gone. And I was told not to ground this wire by many here at the forum and even some performance shops.
So this is for you

 

Another solution I considered would be to replace the trigger wire with a high quality digital video wire. That would have probably worked too.

And don't blast me for creating a ground loop. My car has excellent body and engine grounds (plural). Double grounding shouldn't be a problem.

 

Good stuff! I've run into this a bunch of times and many times it's made me scratch my head. One time the only way I was able to tune the car was with the alternator removed :/

B

 

The saga continues...

Upped the boost to 12psi and the trigger issue persists. Replaced the trigger cable with a high quality xlr mic cable...no good. However, the real problem is not directly the cas signal but spark scatter from the MSD box at high loads.
The car pulls really hard to about 5psi then flatlines (powerwise) even as the boost climbs. AFRs are good so I knew it must be a spark timing issue. It's also very repeatable--not like a bad set of plugs.
The ignition for the leading (msd) was set up as constant charge 3.5ms rising edge. Trailing (with ls1 coils) was constant charge falling edge. Apparently the MSD does not like a constant charge signal so the spark was all over the place. Felt like I was hitting a rev limiter. This makes sense since the msd white wire was designed to run off a points system, which outputs a constant duty based on rpm. Only EFI is really able to calculate constant charge times.
Before leaving the shop, I set it to constant duty 50%. The car runs much, much smoother. At 12psi it starts to breakup a little so I'm going to try 30% duty and change the plugs.

One side note:
When I switched the leading to % duty (leaving the trailing at constant charge), it took away my "ms of charge time" box. Is the trailing running a constant charge still???

 

Set duty % at 30 then 25, 35, 37, and 45 with no success. Went back to constant charge 2ms and, again, missfires under boost at high rpms.

Turned out to be the MSD 6a box I was using. I don't understand since it had a really hot spark at idle and held its timing there too. I am now using the stock igniter, TII coil, wasted spark, with Ls1 coils on the trailing. 3.1ms charge time.

Since then I have made several long 4th gear pulls without a single miss.

As far as the tach bouncing, I believe the E8 needs some consistancy from the crank rotation to maintain sync. Missfires or detionaton can through off its sync on the trigger signals.

 

I too, have had a weird jump in rpms and missfires for the last three years.

Most of the time it is a small jump on my data logs and I never feel it. Had a jump tonight that went from 6500 to 7500...I felt that one.

I reduced my gains from 2 to 1 on the e6k....made a much cleaner pull but, not perfect. Since this is an intermitant problem it is hard to know what is helping.

I'll change it to 0 and see if that helps even more.

Can I put tin foil with a ground wire around the alternator and FC1000 ingition box to block rfi?

It would be nice if someone could measure the type of trigger signal and compare it to other things in the engine bay. Maybe we can then have soild answers.