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  #1  
Old 06-01-2018, 09:29 AM
mattmoox mattmoox is offline
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Location: Fairfax, CA
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Fix for SVX stalling issue with stock ECU and manual transmission

Hi folks,

For those of you with an EG33 with the stock SVX ECU and a manual transmission: you are likely experiencing stalling when coasting to a stop when the engine is hot. This is due to the ECU being programmed for an automatic transmission which triggers Deceleration Fuel Cut Off (DFCO) when the engine is hot and you are coasting/decelerating to a stop.

I have a simple fix for this which has been working well for me in a variety of driving conditions: When depressing the clutch (and ONLY when depressing the clutch), ground the ECU Neutral pin (B10) and add a 200 ohm resistor in series with the coolant temp sensor. This can be achieved with a switch on the clutch which triggers a DPDT relay.

The reason this works is because the additional 200 ohm resistor in series with the coolant temp sensor tells the ECU that the engine is not fully warmed up. When the engine is not fully warmed up, DFCO is disabled.

Before implementing this mod, be sure to make sure the following components are set to stock settings: TPS, throttle stop screw, IAC valve, Aux air bypass valve. If you are like me, you probably already spent hours fiddling with these to solve the problem, to no avail. Enjoy.

Cheers,
Matt
Fairfax, CA
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  #2  
Old 06-01-2018, 12:20 PM
mattmoox mattmoox is offline
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Re: Fix for SVX stalling issue with stock ECU and manual transmission

Also, this fix works with a cold, warm, or hot engine with AC on or off.
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  #3  
Old 06-01-2018, 04:00 PM
mattmoox mattmoox is offline
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Re: Fix for SVX stalling issue with stock ECU and manual transmission

Here’s a schematic...
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  #4  
Old 06-01-2018, 05:36 PM
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SURTEESS SURTEESS is offline
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Re: Fix for SVX stalling issue with stock ECU and manual transmission

where is the stock ECU located, I need to open mine up to see what is causing CEL 45 (atmospheric sensor error).
TIA
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1995 LSI, Added the following - Gear Firm-Up unit (that I sell) together with Power TCU ROM & Power switch, K&N air filter, SVX side badges (USA type), Rear Deck Blower (JDM type), Side front markers (USA type), Side rear markers (USA type), Middle rear light (USA type), USA OEM Fog Lights fitted into NZ OEM glass (NZ OEM headlights had only reflectors fitted) Full set of yellow (90SH) Polish bushes includes 15 min mod, R1 Concepts drilled/slotted/gold finish rotors & Red covered braided brake lines (both from Dayle at Motorsport warehouse), EBC Redstuff brake pads. Full SVX bra (only used for shows). Koni adjustable inserts fitted inside OEM strut body, Zoom lowering springs (2" lower), OEM headlight washers fitted.
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  #5  
Old 06-14-2018, 01:31 AM
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stiguy stiguy is offline
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Re: Fix for SVX stalling issue with stock ECU and manual transmission

You need to share this on svxnation facebook!
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#3 1992 Lsi pearl white - sold
#4 1992 Lsi pearl white -Ate two engines - Rip
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  #6  
Old 06-15-2018, 05:29 AM
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huck369 huck369 is offline
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Re: Fix for SVX stalling issue with stock ECU and manual transmission

Quote:
Originally Posted by SURTEESS View Post
where is the stock ECU located, I need to open mine up to see what is causing CEL 45 (atmospheric sensor error).
TIA
It's located under the dash, near the kick panel on the drivers side, have to pull the lower dash trim off
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