Has anyone had a failed FCD? Are there testing methods for a FCD?

 

Yes you can test for the clamp voltage. I dont see how anything can really go wrong with one unless it was flooded with water and not waterproofed.

 

clamp voltage? any other ideas for FCD testing out there?

 

dr0x is saying check to make sure the voltage is stopped where it should be stopping, IE if fuel cut is at 4V then you want your FCD to "clamp" or hold the voltage at 3.9V. That way, your ecu will still put out the maxium amount of fuel the stock ecu will allow. I dont remember what the real voltage is, I'm just using 4v as an example.

 

On a 87, stick the positive lead of your digital meter in the back of the brown/red wire on the boost sensor electrical connector. Turn the key to on. Now put a source of pressure on the boost sensors nipple and apply pressure up to ten psi.

The voltage at the brown/red wire should stop rising at approx 3.65 volts. Write back and tell us what it did stop at.

For a source of pressure, by a MittyVac at Pepboys. You can use it for a variety of jobs other than this.

 

Hailers, thanks for the testing tips, While I am in the shop replacing the turbo I will pressure test and report back. I figure within a week.

 

testing shows a 3.35 clamp voltage, I would guess base on the gauge that is about 8.5 psi.

Question?

Is it safe to say my ECU is running at a 8.5 psi anytime i am over that value?

 

See the chart in this url: http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm

For some reason they set them low (RB). I bought one and then built one. I use the one I built. I set it at 3.65 maybe 3.70 Like I say read the article.

The one I bought from Rotary Performance had a clamping voltage like yours. Somewhere around 3.35. I know that is toooo low. So I reset it. It now sits on a shelf. The DIY is working just fine.

Let me ask you this: where does your factory gauge peg when you are at full boost. How many marks from the top???? I'd reset the fcd to closer to 3.7volts myself.

 

Hailers, my stock gauge pegs I believe, cause I am watching my autometer gauge telling me 10-15 at times.

 

I've had mine, as a plug-in to the boost sensor, in for about a year and a half now with no problems. With my questionable soldering even.

 

HAILERS,

So 3.65 is the reading you want to see clamped? I just got the RB model 11570, and I havent even installed it or adjusted it.

Jarrett

 

In about 3 weeks I will be selling my rb fcd very cheap. Going Microtech. Will also have stock wiring and junk too. Let me know!

Also if you pop the top off of rb's fcd theres a pot which you can turn. It will be covered in goop but you can still manage. I set my rb to about 3.5 volts.

 

J-Rat...........I think the maker thinks its best at 3.35. Sorry, he's wrong. They put a little bit of torque seal over the adjusting screw either to lock it in place.....or to see if you've been a messing with it when you try to return it and get your money back.

My homemade one I put in a abs case and flooded it with potting compound to prevent water saturation/whatever, from destroying it.

If you have a source of vaccum and a boost gauge like the infamous Autometer, you can see what its set at as described in the above post. Don't even have to start the car.

But while I'm here shooting my fingers off, I do believe I had the car idling when I was applying the 10psi boost to the boost/pressure sensor, and I cut the fuel to the rear rotors. Almost positively sure I did that sitting in the driveway idling.