Cold start issues

Chuck Leeper

Toxic old bastard
Staff member
Joined
May 28, 2001
Finally, got a cold start log.
Seems the idle is rough, uneven, and shows some wild afr on the WB. [New PLX]
The engine is stock internals, new springs, turbo, 60# injs, TT chip to match, LS MAF/Translator, GM coil and module, Russ Merritt wires, AC plugs. All parts are new.
This is the first start since the engine has been reinstalled w/ the above changes.
Translator is set to original suggested settings.
Closed loop comes on at an indicated temp just over 100*.
Here's a log. NE 1 care to venture what may be wrong?
Note that fp is showing 56-60psi. It's actually 42/43, line off!
How do I use the adjust feature to get this corrected???

TIA,:D
 

Attachments

  • COLD ST 122515.dat
    228.4 KB · Views: 57
Last edited:
You have to mess with the powerlogger custom settings 4 psi the max value.gauge max and graph change them the same amount
[Comm]
AutoPort=1
Port=0
GraphSkip=0
FrameRate=18
[Startup]
Page=1
AutoConnect=0
[Graphs]
Graph1Channel=0
Graph2Channel=1
Graph3Channel=2
Graph4Channel=3
[Data]
MAFRangeIndex=0
Barometer=101.300003051758
VehicleSpeedScale=1
ECMReferenceVoltage=4.94999980926514
AFRChartMax=16
AFRChartMin=10
BoostChartMax=30
BoostChartMin=-20
[Norbs]
O2GaugeSetting=0
[AnalogChannels]
Analog1=0
Analog2=0
Analog3=0
Analog4=0
Analog5=0
Analog1Filt=0
Analog2Filt=0
Analog3Filt=0
Analog4Filt=0
Analog5Filt=0
Analog1OffsetVolts=0
Analog2OffsetVolts=0
Analog3OffsetVolts=0
Analog4OffsetVolts=0
Analog5OffsetVolts=0
[DisplayConfig]
AnalogSpark=0
[Custom]
LV8Gauge=0
[ScanmasterConfig]
DisplayWB=0
DisplayMAP=0
DisplayBoost=0
DisplayEGT=0
DisplayAutoBaro=1
[Triggers]
TPS=3
KNR=10
MinRecordingSec=10
TPS_TrigEnabled=0
KNR_TrigEnabled=0
NewDTC_TrigEnabled=0
[QuickSave]
DefaultFilename=QuickSave
DefaultComment=Quick Save File
FileSerialNumber=0
AutosaveAfterRecording=0
[ConverterSlip]
RatioLowGear=0
RatioMidGear=0
RatioHighGear=0
[Warnings]
KnockWarningThreshold=0
RPMWarningThreshold=5500
[CustomAnalog4]
CustomAnalog4Name=Pressure4
CustomAnalog4LongName=Analog Input 4 Pressure Sensor
CustomAnalog4Tag=PR4
CustomAnalog4GaugeMin=0
CustomAnalog4GaugeMax=150
CustomAnalog4GraphMin=0
CustomAnalog4GraphMax=150
CustomAnalog4MinValue=0
CustomAnalog4MaxValue=150
CustomAnalog4MinVolt=0.5
CustomAnalog4MaxVolt=4.5
[CustomAnalog5]
CustomAnalog5Name=Pressure5
CustomAnalog5LongName=Analog Input 5 Pressure Sensor
CustomAnalog5Tag=PR5
CustomAnalog5GaugeMin=0
CustomAnalog5GaugeMax=150
CustomAnalog5GraphMin=0
CustomAnalog5GraphMax=150
CustomAnalog5MinValue=0
CustomAnalog5MaxValue=150
CustomAnalog5MinVolt=0.5
CustomAnalog5MaxVolt=4.5

here set to 150 max go down 5 at a time a.see what you got and go from there .
 
They max at 150 so start by going down like 10 .(140) see where its at go from there .
 
Try "1" for MAF Base. It looks like its way lean for some reason. Could be a MAF issue, or vacuum leak. Also need to get it warmed up so the BLM will start learning.
 
Try "1" for MAF Base. It looks like its way lean for some reason. Could be a MAF issue, or vacuum leak. Also need to get it warmed up so the BLM will start learning.

Checked for leaks.. Found none, but that doesn't mean .....:bucktooth:
The 1 setting appears to be a good change. I'll run another cold start, and let it get up to temp.. Has a 160 in it, now.

Thanks!(y)
 
Try "1" for MAF Base. It looks like its way lean for some reason. Could be a MAF issue, or vacuum leak. Also need to get it warmed up so the BLM will start learning.

Warmed it up to get the BLM recording, and lost the damn log!:mad: Will do it again, in the Am.
However, I ran it to 200*, and the fan did not come on. What are the fan settings on that chip?
I checked all the fan wiring, etc. Could not find a problem that would not allow it to work.

TIA,(y)
 
Fan switch ? on the intake .

The ecm sensor and the aftermkt gauge sensor both work. [Both gauges work, altho, the aftermkt reads 10* lower.]
I have gone thru the t/s tree, and found no issues.
I can grnd the overtemp sensor wire, and the fan runs. I also checked the resistor, and bypassed it.
Not sure where to look next. I will get the service man out, and retrace the system, again.
I have to do a cold start log in the am, so I'll rechek the system, B4 I do the start up.
 

Paul, that was the tree I followed last time. I must have missed something. I found no issues, other than the plug at the a/c pipe, behind the compressor, was unhooked. Once I plugged it in, all checked gtg...Guess not!:unsure:

Thanks for the help, guys. I'll find it, sooner or later!

UPDATE: Appears the low speed resistor has taken a dump. [Whoda thunk it??]
I guess I'll just jump across it, and call it good, unless I can find another.
I tested it w/ an ohm meter.. Shows OL.:(

Update 2:
Pulled the resistor and had a bitch of a time getting the screws out at the connectors.
Once cleaned up the resistor checked at .3ohm.. Exactly what it should. I had just wired the + wires together, and went thru all of the checks, including back to the ecm pin D2/C1. Signal wire, [dk green] is good.
Started the engine, got to 169*, and PL showed fan commanded.....NO FAN!o_O
Went thru the tests again.. Have now traced the issue to the pin/connector in the ecm.
Have continuity from both sides of the ecm plug, so the green trigger wire is gtg.
Next is a cold start w/ a test light wired into the engine side of the green wire. Once at op temp, I will be able to determine if the signal is making it thru the ecm pin and the plug. [Or, if the signal is not there, even tho the PL says it is.] In which case, I'll put another ecm in place, and see wtf happens....
 
Last edited:
FINALLY....Found the culprit. The used ecm I bought for use w/ the PL, has the fan circuit inop.
I put a different ecm in, whamo.. fan cycles on at 169, off at 164/5.

Thanks for the help!
 
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