Low resolution on SC knob on HFS3

[bradyzq]

Hi All,

First post transferred from PM convo with Richard L:

Quote:
Originally Posted by bradyzq

Hi,

I am trying to dial in the failsafe on an HFS-3. I will interrupt power to the boost controller through a relay triggered by the failsafe ground signal.

However, from the detent at about 11 o'clock to the next detent at 11:30, the gauge goes from 3 bars to 8 bars. I want 6 bars as per the instruction booklet. I measured the flow of the 2 jets (1.2mm and 0.7mm) at 12V (key on car not running) with the SYS jumpered. In 60 seconds, about 2 and a third empty Corona 330ml beer bottles were filled. So that looks about right. All the trims in the controller are untouched.

What can I do to resolve this?

Cheers,
Brady Moffatt
www.dynodoc.ca
info@dynodoc.ca
1-514-396-9390

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Quote:
Originally Posted by Richard L

Can you tell me the serial number of the H3 controller.

Richard

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Quote:
Originally Posted by bradyzq

SN:101283 HFS-3 V3

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Quote:
Originally Posted by Richard L

Can you check the flow table is not changes. page 21 of the user manual. It appeared that you have an over sensitive flow map.

Can you measure the voltage of the pad marked "1".

Richard

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Quote:
Originally Posted by bradyzq

Voltages with reference to a ground test hole on the board, at pads 1, 2, and 3 (as shown on page 20 of the manual and on the actual board) or on pads 0, 1, and 2 as shown on page 21 of the manual, are the following:

0V, 2.5V, and 5V respectively.

These were measured with SYS jumpered and the jets in the air (not in the intake), so they should have been spraying at 100%DC.

I just tried the BAR test, and the bar graph moves in sync with the SC trim knob as expected.

The flow map sticker is 80-160-400.

Cheers,
Brady

[Richard L]

Please try another flow table - solder link 2+3 (Page 21) V3.0 user manual

[bradyzq]

I got exactly the same result with the 2-3 pads jumpered. bummer.

Though technically, from one detent to the next, the SC bars jump from 3 to 7 with a flickering 8th, not directly to 8.

What's next?

===============
Cheers,
Brady

[Richard L]

can you read the voltage of the pads when 2&3 is linked.

[Richard L]

also check the voltage divider R3 and R4. Look for dry joint.

low flow table = 0V
medium flow table = 2.5V
high flow table = 5V

[bradyzq]

The voltages at pads 1, 2, and 3 are now 0V, 5V, and 5V. I measured this at key on engine off. Previously, I had measured it while spraying with SYS jumpered and the nozzles in the air.

R3 and R4 seem fine. Have we not effectively bypassed R4 by joining pads 2 and 3?