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turbo rotary FD busy serially eating electronic modules

 
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howard coleman



Joined: 29 Nov 2006
Posts: 14

PostPosted: Thu Sep 29, 2011 10:58 am    Post subject: turbo rotary FD busy serially eating electronic modules Reply with quote

i haven't been on this board for a few years but consider it to be populated with some high hp elec talent and do hope someone can point me in the correct direction.

i have a seriously modded dual purpose late model turbo RX7. most of it was built by me in 04 and it ran fine until 09.

on the car from 04:

Apexi Power FC
Datalogit interface to laptop
Kenne Bell Boost A Pump running +20% V gain
Cosmo pump
two Jacobs FC3000 amps
two MSD 8253 coils
each of the above runs one lead NGK 6725 plug
in 2010 i added two MSD 8207 coils to drive the trail plugs
J&S knock sensor (drops lead spark 10 degrees in knock)
Alkycontrol methanol system
in 08 changed to FJO meth system
04 09 twin TO4E setup... made 507 SAE at 20 psi
(continued post 2)


Last edited by howard coleman on Thu Sep 29, 2011 11:13 am; edited 2 times in total
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howard coleman



Joined: 29 Nov 2006
Posts: 14

PostPosted: Thu Sep 29, 2011 11:06 am    Post subject: Reply with quote

while i have no idea if related to my 09/10 problems i did buy a "high output" alternator in april 09.

the car was down for much of the balance of 09 other than a dyno session in may where ran well and made 507 SAE at 20 psi. i then converted it to a T56 6 speed, designed a single manifold and was back on the dyno nov 10.

it blew the Datalogit
it blew the Kenne Bell Boost A Pump (showing 24+ amps at the fuse)
and shortly thereafter it blew the front primary injector driver.

(secondaries run by FJO Peak and hold converter) (850/1600)

i replaced all modules w new. i returned to the dyno this Aug and we found we weren't getting alcohol.. the FJO meth module had blown.

i have since converted the secondary injectors to Bosch EV14 and added 2 additional similar injectors to my Greddy elbow and they are wired thru my FJO peak and hold so as to lessen the strain on the Power fc.

(cont)
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howard coleman



Joined: 29 Nov 2006
Posts: 14

PostPosted: Thu Sep 29, 2011 11:12 am    Post subject: Reply with quote

after making the conversion i started the motor and find it is again running on only the rear rotor. there is no signal from the Power FC to the front primary injector. this is the exact same situation as w the first Power FC.

i did a new OE wiring harness back 6 months ago. have checked continuity, swapped the primary injectors, done compression and coolant pressure tests etc and it ends up, no signal to the primary injector from either of the blown Power FCs.

i inserted a stock ECU and the motor runs on both rotors. i have checked ignition spark, as well as the plugs.

my logs show a consistant 13.3 to 13.4 volts.

question: what could be causing the series of failures?

thanks for reading.

howard
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Warpspeed



Joined: 05 Jun 2006
Posts: 553
Location: Melbourne

PostPosted: Thu Sep 29, 2011 12:42 pm    Post subject: Reply with quote

You need to find out what actually stopped working in the failed modules.
If you can discover that, then it may give you some clue as to a cause.

Sounds to me like there are either some massively high transient voltages on your twelve volt supply, or you have just been extremely unlucky with a bunch of completely unrelated random failures.

First step would be to get someone to look at the modules that failed and try to figure out what happened.
Some of them may even be easily repairable ?
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John at J&S



Joined: 12 Nov 2005
Posts: 291
Location: GARDEN GROVE, CA

PostPosted: Thu Sep 29, 2011 1:21 pm    Post subject: Reply with quote

Install a V24ZA50P MOV between 12v and Gnd at the input of the units.

I started using them in 1990. Prior to that I had a couple units come back with dead processors. A voltage spike must have taken out the 5v regulator. 12v was present on the output.

A couple years later I was at BDS and Craig opened up a MEFI unit, revealing the same MOV.
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howard coleman



Joined: 29 Nov 2006
Posts: 14

PostPosted: Thu Sep 29, 2011 2:11 pm    Post subject: Reply with quote

Warpspeed, thanks for your reply. the FJO unit is milspec and the Kenne Bell is fully potted and both units have a strong rep for dependability. of course that doesn't mean they are failsafe. the unusual string of items and compressed timeframe indicates something is amiss w the global system.

John,
thanks the reply. i do appreciate your input and have been very pleased w your knock ignition retard under boost unit. (which hasn't failed)

would you have any idea as to why i might have experienced a V spike? what areas of the system might i spend time with...

i have looked at alot of my logs w my Battery Voltage set to max reading and haven't seen anything above 13.7 V. given my serial failures it would seem that i do have a spike problem.
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John at J&S



Joined: 12 Nov 2005
Posts: 291
Location: GARDEN GROVE, CA

PostPosted: Thu Sep 29, 2011 2:17 pm    Post subject: Reply with quote

Howard:

The voltage spike may only last a few microseconds, so your data logger wouldn't capture it.

http://www.littelfuse.com/data/en/Application_Notes/an9312.pdf
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Warpspeed



Joined: 05 Jun 2006
Posts: 553
Location: Melbourne

PostPosted: Thu Sep 29, 2011 2:39 pm    Post subject: Reply with quote

John is right on the money with this.

There are many possible sources of transient voltages in an automotive electrical system. The two biggest causes are alternator load dump, and inductive spikes. The problems are well known and well understood by the designers of vehicle electronics, and anything susceptible always has some inbuilt protection provided.

And john is quite right, a data logger just takes a snapshot if the voltage at one instant in time.
It is much more likely to miss a very fast voltage spike than to capture it.

It is difficult to speculate about your problem, as quality automotive electronic products always have some inbuilt protection from these well known problems. But fitting some extra MOVs as John suggests, cannot hurt.
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John at J&S



Joined: 12 Nov 2005
Posts: 291
Location: GARDEN GROVE, CA

PostPosted: Thu Sep 29, 2011 3:12 pm    Post subject: Reply with quote

I built a retard module for a team in '98. They sent me a NASCAR Crane HI-6 to play with.

Everything worked fine using a resistor coil wire, firing a spark plug in a 100psi chamber.

For fun, I replaced the resistor coil wire with a clip lead. The HI-6 made exactly one spark and died. My module still worked.

I looked at a HI-6 in the early 90's. It had a small MOV on the 12v input.
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howard coleman



Joined: 29 Nov 2006
Posts: 14

PostPosted: Thu Sep 29, 2011 5:17 pm    Post subject: Reply with quote

thanks lots to both of you. i appreciate the link and will have fun w the 12 pages tonight. when i find the root of the problem i will post it.

one item (page one of the link) that did get me thinking is...

while on the dyno, which is where many of the failures occurred, i have had my battery charger hooked up (10 amp charge rate) just to assure i had enough elec firepower. perhaps something could be going on w the charger and the car.

it is the newer style Schumacher SpeedCharge charger set to AGM.
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C. Ludwig



Joined: 29 Sep 2006
Posts: 355

PostPosted: Thu Sep 29, 2011 11:48 pm    Post subject: Reply with quote

howard coleman wrote:


while on the dyno, which is where many of the failures occurred, i have had my battery charger hooked up (10 amp charge rate) just to assure i had enough elec firepower. perhaps something could be going on w the charger and the car.



DING, DING, DING. I believe we have a winner!
_________________
Haltech, Syvecs, AEM, Apexi PFC Sales, Installation, Tuning
Custom Harness Solutions
www.ludwigmotorsports.com
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howard coleman



Joined: 29 Nov 2006
Posts: 14

PostPosted: Fri Sep 30, 2011 5:04 pm    Post subject: Reply with quote

all the elec modules that failed had fuses. none blew

the ECU (Apexi Power FC) has a 30 A fuse

the Boost A Pump has a 20 A fuse

the FJO meth module has a 15 A fuse

the single fuse that failed was the OE fuel pump fuse. my Boost A Pump (BAP) works under manifold pressure only.

as we entered boost the 20 A OE fuse failed. Luke replace the fuse w some sort of test instrument that read Amps in real time. we could see them climbing to 24 and ended the pull. the fuse on the unit did not blow... of course that is the fuse in the line to the BAP. the fuse that was blowing is measuring output from the module to the fuel pump.

if i would have had a spike from Voltage Dump wouldn't that have caused
most of the fuses to blow? (cont)
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howard coleman



Joined: 29 Nov 2006
Posts: 14

PostPosted: Fri Sep 30, 2011 5:09 pm    Post subject: Reply with quote

on another issue

Apexi Power FC repair. the Apexi option is a long one, 2 months.

does anyone know of anybody that could replace the primary driver components?

thanks all,

howard
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Warpspeed



Joined: 05 Jun 2006
Posts: 553
Location: Melbourne

PostPosted: Fri Sep 30, 2011 5:31 pm    Post subject: Reply with quote

A voltage spike will not directly blow a fuse, only an excessive current draw will do that.

Sometimes a voltage spike can destroy a circuit causing it to short out and draw excessive current. That can blow a fuse.

Or a spike may just destroy a part of the circuit causing it to draw very little or no current. Different types of failures cause different effects.

If this is an over voltage problem, only two solutions.
Fix it at the source, or provide some voltage clamping.
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howard coleman



Joined: 29 Nov 2006
Posts: 14

PostPosted: Sun Oct 02, 2011 10:41 am    Post subject: Reply with quote

"Alot of relays have voltage suppression diodes in the circuit."

take a look at my relay... it is the X036, the one with the big white space in the coil surpression box.



at some point before the carnage my shop decided to replace the AI pump relay w the above.

the relay replaced was the R1 (no connection the the FD R1) on the following list. note it has a flyback resistor or diode..



thanks to the guidence of the above contributees (what did i do before the net?) i am have learned a bit about voltage spikes... and an easy way to generate them is with a relay that doesn't have a high voltage spike lockdown.

volt spikes, because they have little current can go right thru a fuse and if they get into any solid state components it is sudden death.

when a relay gets the signal to turn something off, say a pump, the magnetic field collapses and as much as 200 volts can be created and it heads backwards towards the controller, the diode or resistor stops it cold.

i was wondering how i lost my last Power FC since it was dead on startup... then i remembered that i was testing my new boost switch pump trigger setup and i did turn the pump on and off a few times by jumping the switch.

poof, another Power FC in need of repair.

if you are adding a relay...

i do have a question for you circuit knowledgable guys... i can clearly understand the failure of the solid state pump control module as it is in the direct path of the V surge. can this spike effect ofther modules within my harness?
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Warpspeed



Joined: 05 Jun 2006
Posts: 553
Location: Melbourne

PostPosted: Sun Oct 02, 2011 3:14 pm    Post subject: Reply with quote

howard coleman wrote:


when a relay gets the signal to turn something off, say a pump, the magnetic field collapses and as much as 200 volts can be created and it heads backwards towards the controller, the diode or resistor stops it cold.

I can clearly understand the failure of the solid state pump control module as it is in the direct path of the V surge. can this spike effect other modules within my harness?


The spike can be generated by the wiring harness itself, or any inductance in series with either the supply or the ground path.

A coil is inductive because, it contains many turns of wire which greatly magnifies and concentrates the effect of a changing magnetic field.
But even one turn will be inductive, or even a short straight piece of wire can be very slightly inductive to a very small extent.

If you find that very difficult to believe, it is exactly how a radio antenna works.

The winding in the alternator is undoubtedly a very high inductance and also in series with the main current supply path to everything else.
Turning the starter motor on and off is a pretty large and sudden load change for the whole system.

Anything that causes a very rapid current change through the wiring harness can generate voltage spikes. As soon as you switch some load somewhere rapidly either on or off, transient voltages may appear throughout the whole system.

Another source of very rapid voltage spikes can be caused by radiation from the plug wires back into the engine wiring harness. It is not only your radio reception that can sometimes suffer when you fit some super high output aftermarket ignition system and ditch the factory carbon plug wires.

There are many possible causes of this electrical interference problem when you start fitting extra powerful bits and pieces to your cars original electrical system.
Many high powered automotive accessories work fine in isolation, but can disturb other vulnerable parts of the system.
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howard coleman



Joined: 29 Nov 2006
Posts: 14

PostPosted: Sun Oct 02, 2011 5:02 pm    Post subject: Reply with quote

thanks for the input Warpspeed and after a bit of research quite understandable. my system, as i wired it, worked perfectly for four years. the only new items on the scene were the relay that did not contain either a diode or resistor, the new alternator and the addition of the battery charger while running on the dyno.

i will swap alternators, check my wiring integrity, switch to a proper relay and add an MOS varistor in front of all solid state items as well as losing the charger while the engine is lit.
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goodone963



Joined: 25 Mar 2019
Posts: 2

PostPosted: Mon Mar 25, 2019 12:24 am    Post subject: Reply with quote

Custom wire harness solutions https://www.allicdata.com
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goodone963



Joined: 25 Mar 2019
Posts: 2

PostPosted: Mon Mar 25, 2019 12:25 am    Post subject: Reply with quote

Custom wire harness solutions https://www.allicdata.com
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