Starts and Stalls

s300 and SManager software questions & answers
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Johnny_9
Posts: 312
Joined: Sun Apr 09, 2006 5:12 am

Post Start - When does closed loop start

Post by Johnny_9 »

How soon after starting does closed loop start? Need to know what temp. fuel compensation to adjust; form the log it seems the high load open loop is kicking in, at idle when stationary, even with no depression of the throttle
Johnny_9
Posts: 312
Joined: Sun Apr 09, 2006 5:12 am

Starts and Stalls

Post by Johnny_9 »

After cranking fires and stalls - I Think I am too rich. Do I adjust

the map or the any of the compenstions or post start fuel

Hot idle INJ = 2.3ms for reference

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Johnny_9
Posts: 312
Joined: Sun Apr 09, 2006 5:12 am

Re: Post Start - When does closed loop start

Post by Johnny_9 »

Johnny_9 wrote:How soon after starting does closed loop start? Need to know what temp. fuel compensation to adjust; form the log it seems the high load open loop is kicking in, at idle when stationary, even with no depression of the throttle
Answer:- (from flashpro help)
When the engine speed reaches 600 rpm the ECU determines that the engine has started (note 4). At this point the last closed loop start term fuel trim (from when the engine was shut off) is applied to the main table fuel. For the first 10-30 seconds of engine running the injector pulse is determined from both the cranking fuel and main fuel tables. At first only the cranking fuel is used, and is progressively replaced by the fuel value from the main fuel tables (note 6)
Johnny_9
Posts: 312
Joined: Sun Apr 09, 2006 5:12 am

Re: Starts and Stalls

Post by Johnny_9 »

If your engine starts well but stalls after a few seconds, generally the start values are OK but the ET values are too low. You only get one try per starting attempt to set the number of start cycles and start fuel values so this may take some time to set up. For ET values, you can often set these quite well in one sitting by using the following procedure:

Start the engine and call up Gauge 1 mode to monitor the ET. As the ET changes, move the mixture knob slowly richer until the engine begins to stumble, now lean it slowly until you get a stunble again. If the the knob can be turned about the same amount on either side of the 0% mark before encountering a stumble, the ET value at that temperature is close. If you just turn the knob a few percent lean and it stumbles, the value at that ET needs to be slightly higher. Scroll to the ET values and change the one at the current ET to compensate.
Johnny_9
Posts: 312
Joined: Sun Apr 09, 2006 5:12 am

Re: Starts and Stalls

Post by Johnny_9 »

Johnny_9
Posts: 312
Joined: Sun Apr 09, 2006 5:12 am

Re: Starts and Stalls

Post by Johnny_9 »

What is the best strategy to adjust first (my cranking seems OK, engine fires (get up to 1200 rpm)

Post start fuel trim

or

Open loop ECT Fuel Trims
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