LinkPlus (G1) Cold start adjustments

[Esa Hintsala]

I have problems with Cold start. Engine will start, but it requires several 3-4 seconds crankings. Warm start is quite ok, only short (usually 1 second) crank will be enough (not as easily as with std ECU, but well acceptable). Engine is tuned with head porting, compress ratio, cams, exhausts and intake. But not wildly. I have tried to adjust Cold Start (currently 32), Prime Temp (Currently 2 degrees), Crank Decay (currently 20) and Crank Enrichment (Currently 81). And also Zone 100 (upper left corner, currently 83) in the Fuel Map. Prime temp tends to overflood engine and it has been in zero so far. I have now inspected it with 2 degrees setting (it is winter here and seems that prime is required). I cant get the full idea from manuals how Cold start, Crank Decay, Crank Enrichment, Prime temp and Fuel Map cell 100 work together during cranking, when starting and when engine warms up. Here are the explanations from manuals and my questions: -- Cold (Post-Start warm-up) Controls cold start and warm up enrichment by adding extra fuel to the engine. The adjustment value is shown on the right hand side of the display and will gradually reduce to zero as the engine temperature rises towards 70¡C. Note this is the temperature-decayed-value rather than the full cold value. The number shown in parenthesis (xxx) is the actual engine temperature for monitoring purposes. -- So this works after Crank Enrichment (Crank Decay?) has been already faded away? This is the easiest to adjust and I think I have managed with this well, because after a say 10 - 20 seconds after starting, engine runs well, a little bit rich but not too much. I have wide band oxy display with providing 0-1 V input to LinkPlus. Sometimes I get the feeling, that adjusting other mentioned cold start parameters will also have effect on post-start warm up. Is this correct? -- Prime Temperature This allows the pre-start injector prime temperature to be adjusted. At low temperatures the mixture formation is inadequate to start the engine. This is due to the poor mixing of air and fuel, as well as fuel condensation on the cylinder walls. To compensate for these losses, if the engine temperature is BELOW the prime threshold at key-on, the engine will receive a short injector shot to assist starting. Note this setting is checked when the LinkPlus is powered up, so any adjustment will only take effect if the power is recycled. Use the ADJUST buttons to alter the temperature. -- Does the LinkPlus provide similar prime each time, when I have to make reattempted crankings? My ignition switches off and on between reattempts, cant help this. This tend to overflow engine. I havent used this so far because of that, but in the cold weather, my other adjustmenst just dont provide enough fuel for starting, even in warmer temperatures they work well. When this adjustment is activated, it many times ruins the starting totally. Especially if I have to make several attempts. Engine starts finally, but smokes and runs very rich a long time. The other way would be to deactivate Prime and change Crank Enrichment to provide more enrichment during wintertime. Do you recommend one long crank instead of several short ones? -- Crank Decay This controls the rate at which the crank enrich fuel is removed. The larger the number, the longer it will take to remove this fuel. Use the ADJUST buttons to change this number. A typical value is 20. Upper limit = 40 (Long decay period), Lower limit = 5 (Short decay period). -- Actually, values 0-150 are allowed, even though manual says 5-40! I cannot use this at all. I have tried to change this, but I havent noticed any effects. What will I get if I raise the value from 20 to higher? When does this work? Only during Cranking? Or during cranking and after engine has started? So does this represent the time when Crank enrichment reduces to zero during cranking? Alternatively, does this represent the time when Crank enrichment reduces to zero after engine has started (does this control the "short period after starting" referred in Crank Enrichment explanation)? When does the Cold start become active then? -- Crank Enrichment This is the amount of extra fuel added while the engine is cranked and for a short period after starting. It is a temperature dependent enrichment and only effective when the engine temperature is below 50oC. The actual value used by the LinkPlus will provide more crank enrichment with decreasing engine temperature and will decay with time (see crank decay). The SMALLER the number, the GREATER the enrichment. The base default value is 70. -- I have used this mostly. This seems to have most effect on Cold start. How long does this have affect? Does this fade away already during cranking, or after the engine has started (as said, I dont understand how Crank decay affects). Fuel Map: I have tried to adjust the Fuel value in cell 100 so that the warm start will produce best results. "Hot restart" adjustment is zero now, so I guess this is the only one affecting the warm start. Giving some throttle during cranking or immediately when engine starts, usually provides negative results (engine tends to stop). Sorry for this very long question. But I have been working hard and long with Cold starting adjustments and I really so appreciate the help!

[ashesman]

First thing we need to know is what engine you are running, which ECU you are running, (ie what version of that ECU v10 or V14?)....  In fact, if you can, send a .pcl file and we will have a look.

[Tim1436215452]

Im very interested in this also. I too have a Link Plus (G1), and am experienceing almost the same problems.

I can get the engine fired from cold, but have to hold and rev the throttle until the engine will run on its own. Warm restarts are fine.

In my case the engine is a Porsche flat 6, It is twin plugged with 6 dual tower coils fired in waste spark fashion.

Which of the four adjustments most affects  post start running?

[Esa Hintsala]

Engine is Ford Zetec-E 2.0i 16V year 99. Dual Coil, group injection. ECU Firmware version is LPV14a 26/11/03. .pcl file below. Thank you! [ConfigByteSize]1 [Memo]"Cold etc","(Map 85 => 87 => 83) 31 33 (Decay 15, Enrich 84) 35 => ","32 => (30, Decay 10 =>15 ","=> 20 Enrich 84), (30 => 33, Decay 20 Enrich 84) (33, ","Decay 20 Enrich 84 => 88)","(Map 83, 33, Decay 20 Enrich 88 => 90) ","(Map 83, 33, Decay 20 Enrich 90 => 86) ","(Map 83, 33, Decay 20 Enrich 86 => 84) Kahdella melko ","hyvin ","(Map 83,33, Decay 20 Enrich 84 => 82) - "" -","(Map 83, 33, Decay 20 Enrich 82 => 80) Ei niin hyvä","(Map 83, 33, Decay 20 Enrich 80 => 82) Hyvä kesällä","(Map 83, Cold 33 => 30, Decay 20 Enrich 82) ","Parempi Kylmemmällä ilmalla 10 C ? Eipä taida","(Map 83, Cold 33 => 32, Decay 20 Enrich 82) Parempi ","Kylmemmällä ilmalla 10 C ? Enpä tiedä","(Map 83, Cold 32, Decay 20 Enrich 82 Prime 2 astetta) ","(Map 83, Cold 32, Decay 20 Enrich 82 => 81 Prime 2 ","astetta) ",,"Lambda Targets 6&7 82 => 90 => 100 => 85","8&9&10 => 105 => 103",,"Overrun vacuum 54 (kesällä tuntui hyvältä) => 47 ",(kylmemmällä?),,,,"Prime 0","Overrun vacuum 16 35 40 55 52 56 54","crank enrich 40 (kesä) => 60 70 80 100 60 55 50 45 40 35 ","30 40 50 70 (cell 15 98++) 50 (84) 60 70 80 85 100 90 100 ","95 90 85 80 75 80 70 65 60 70 80 90 100 85 90 95 90 85 ","80 82 84","Decay 15 (kesä) => 10 5 15 20 25 40 20 10 20 30 40 50","60 10 20 30 40 35 15 12","Cold 38 => 30 34 35 => 30 28 20 10 25 30 35 30 25 20 22 ","13 18 23 25 20 17 10 18 20 27 35 37 35 30 38 40 38 36 34","36 40 38 35 38 40 38 37 36 34 33 ",,"Accel Decay 8 => 6 => 4 => 1 => 6","Wakeup pulse 1 => 0 => 1","Pulse 210 160"," ","Clamp 30 25 35 50 35",,"Inlet air 25 18 23 22 21",,"Lambda Targets 6&7 82 => 90 => 100 ","Ylemmät ","85 => 90 => 105","Idle Hot 48 46 50","Airc enrich 5 6",,"Accel table 0-2000 16 => 10 => 6 => 0 3 6 10 16","Lambda 1250 => 1500 rpm ","Fan step 4 => 6 = 5" [ConfigData],92,0,0,0,146,2,234,1,23,0,0,0,101,108,0,0,97,98,1,2,9,0,10,2,136,0,0,0,49,54,32,61,62,32,49,48,32,61,62,32,54,32,61,62,32,48,32,51,32,54,32,49,48,32,49,54,34,0,0,0,56,247,22,1,56,247,22,1,32,0,0,0,62,32,48,32,61,62,32,49,0,0,0,0,102,127,127,106,96,0,0,0 [LinkMemData],35,127,75,115,53,37,180,15,20,94,48,242,6,60,35,32,32,81,50,52,4,17,16,16,16,16,41,41,41,85,103,103,4,255,103,40,62,141,6,5,21,47,20,20,24,30,50,6,80,10,1,20,160,1,0,32,2,5,20,0,83,67,81,96,103,106,108,109,109,109,109,110,110,110,110,110,110,110,103,103,84,86,88,89,92,101,113,121,126,128,128,127,124,118,113,108,105,105,105,105,91,95,98,103,106,99,92,111,131,138,142,143,140,135,124,115,110,106,106,106,95,106,110,112,120,108,105,133,144,151,152,152,147,141,135,118,114,114,114,114,118,120,123,124,129,127,127,136,146,152,152,152,148,146,140,122,120,120,120,121,124,126,129,132,135,136,140,144,155,158,159,158,153,150,144,131,130,130,130,130,139,140,141,142,145,147,150,154,166,174,175,172,165,156,150,144,140,137,137,140,148,149,151,154,156,158,160,165,178,186,188,182,173,165,160,154,152,150,147,145,148,149,151,154,156,158,160,165,178,186,188,182,173,165,160,154,152,150,147,145,148,149,151,154,156,158,160,165,178,186,188,182,173,165,160,154,152,150,147,145,15,10,5,0,20,29,32,33,33,33,33,33,33,33,35,35,35,35,35,35,7,10,16,22,28,32,33,34,34,34,34,34,34,34,34,34,34,34,34,34,13,13,18,23,28,32,33,33,33,33,33,33,33,33,33,33,33,33,33,33,8,13,18,22,24,26,28,29,30,30,30,30,30,30,30,30,30,30,31,31,8,13,18,22,24,26,28,29,30,30,30,30,30,30,30,30,30,30,31,31,8,13,18,24,25,25,25,25,26,27,29,30,31,31,31,31,31,31,31,31,8,13,23,25,25,25,25,25,26,27,29,30,31,31,31,31,31,31,31,31,13,18,23,25,25,25,25,25,26,27,27,28,28,28,28,28,28,28,28,29,13,18,23,25,25,25,25,25,26,27,27,28,28,28,28,28,28,28,28,28,13,18,23,25,25,25,25,25,26,27,27,28,28,28,28,28,28,28,28,28,100,100,100,100,100,100,100,100,100,100,105,105,105,105,105,105,105,105,105,105,30,25,40,0,8,90,55,0,0,0,0,49,10,66,96,118,0,0,0,10,4,14,55,10,0,46,82,32,0,83,15,2,64,0,0,0,0,0,0,0,0,0,161,160,32,33,34,5,114,171,128,97,138,139,224,195,225,226,162,163,130,129,3,6,260,261,7,120,112,113,38,165,166,131,172,121,164,196,78,116,115,173,227,194,18,197,177,178,175,9,19,132,228,0,391,392,393,126,127,199,0,185,231,83,0,0,0,1100,1121,1102,1103,1104,1105,1106,1107,1108,1109,1110,1111,1112,1122,1123,1115,1116,1117,1118,1119,1120,2,1131,2,2,1134,2,1136,1137,2,2,1140,1141,1142,1143,1144,1145,370,371,2,2,2,2,2,2,378,379,380,381,382,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 [CheckSum]37840

[Simon]

Prime fuel is a fixed amount of fuel (20mS) injected at the point the key is turned on if the temperature is below the set value.

If you cycle the key many times you will get multiple lots of prime fuel injected.

Crank Decay is effective on the crank enrichment. It controls how quickly the crank enrichment is removed.
The crank decay/enrichment starts being removed from the moment the engine starts cranking.

[Simon]

PCL file looks ok. Of note is that you are running on TPS  row steps. Is there a reason for this?

The crank enrichment is removed on a per TDC basis. If you have your crank decay set to 20 it will take 20TDC events to remove one unit of enrichment. a value of 30 would take 30TDC events for one unit.

The actual time taken is also affected by you master value.  The bigger the master value the greater the effect crank enrichment has.

[Simon]

Ok would leave row steps as is.

The crank enrichment is removed on a per TDC basis. If you have your crank decay set to 20 it will take 20TDC events to remove one unit of enrichment. a value of 30 would take 30TDC events for one unit.

The actual time taken is also affected by your master value.  The bigger the master value the greater the effect crank enrichment has. As such I can not define this to a given time.

Cold start is effective once the engine has burst.