Starting problem when hot.

[Acesneights1]

I agree with truckie! My 6.5 tow truck would start and run perfect in the morning but after it ran (especially on a hot day) and you shut it off it would crank for about 30 seconds till it started. It would also start fine if you let it sit for about 3 hours.

It ended up being the lift pump under the cab on the drivers side of the frame.

Way to check.... When the problem happens take the fuel filter out and look in the filter housing. Have someone turn the key on and see if fuel is going into tne housing. If not bad pump. IIRC there about $100 from the autoparts store.

It was the first thing I checked. It's pumpin like old faithful. Gonna take GMTDscan for a test drive tonight. If it works , think I'll do a thread on installing it so no one goes through what I did.

 

[Acesneights1]

Sorry guys but I could not figure out a way to copy the screenshot and it was way to much to type so I had to paste it to word docs. They are small but you can expand them. Tell me what you think. Truck started today after sitting a little while but it took a good 30 seconds of cranking. Better than it was though. Before I did the PMD when it sat for an hour it wouldn't start almost at all.

 

[Acesneights1]

So would those timing #s be causing my hot starting problem ?

 

[chrisk1500]

Your injection pulse width is too big.

You have 2 ms. It should be around 1.8 ms.

Check all wires going to the PMD and the ground lug on the IP.

 

[Acesneights1]

I just did the extension harness before I took the snapshot and while I was in there I cleaned the ground for the pump. What else could cause that ? Could the extension harness have too much resistance ? It's 6 foot and seems to me to be of good quality. Has the right ends on it.

 

[chrisk1500]

Remove the harness. Plug the PMD right into the IP harness. What Ctime do you get now?

 

[Acesneights1]

I'll try it later. I have to pull the grill to get it unbolted so it's a little bit. I was reading Your old post on the old site and GMCTDs post about checking the rest of the grounds with a volt meter. Gonna try that too. This all started after I did the following mods:
Feed the beast
New injectors
Turbo master.
I know my lift pump is pumping but haven't actually tested the pressure. Maybe opening up the fuel lines and a possibly weka LP ? This is this only happens when the truck is hot and has sat for 30 mins to 2 hours. It can sit over night and start right up. If I shut it off hot and start it right back up no problem. I was reading alot of people have this problem with 95s/5521 IP which is what I have.
It was having this problem prior to installing the extension harness.

 

[chrisk1500]

Get the ctime figured out first.

Even with good ctime, I had to swap to Duraterm plugs to get good warm starts....

 

[Acesneights1]

I saw that about the duraterms. I just finished reading the entire thread. This is where I get a little lost. The Ctime..could a dirty or failing optical sensor also cause that or is this going to be a voltage/ground problem. Also the timing TDCO @ -.26 affect the CTime. Just trying to get a handle on how the injector pulse time works so it will be easier for me to troubleshoot.

 

[chrisk1500]

TDCO has no effect on Ctime.

It is strictly a voltage thing AFAIK.

Fire gmctd a message and see if he will weigh in on this.

I am under the impression that a slow Ctime will be due to poor grounds, a failing PMD, poor IP wiring, or a bad fuel solenoid.

Check the cheap stuff first.

 

[Matt Bachand]

TDCO has no effect on Ctime.

It is strictly a voltage thing AFAIK.

Fire gmctd a message and see if he will weigh in on this.

I am under the impression that a slow Ctime will be due to poor grounds, a failing PMD, poor IP wiring, or a bad fuel solenoid.

Check the cheap stuff first.

Sounds like we need to 'gather round' for another fine lesson from the wise GMCTD.

 

[94K30]

Kenny, did you have any luck with this? need a hand? I have another PMD and cable if you want to try that.....

 

[Acesneights1]

Kenny, did you have any luck with this? need a hand? I have another PMD and cable if you want to try that.....

Thanks but it was doing it with the stock mounted PMD which was working fine and I put a brand new extension with brand new Dtech and same thing. Chris you said something that makes me wonder. I was outside playing with GMTDscan some more. Since you have it also, tell me what you think of this. It has the engine fuel sol feature. When you turn that on what "should" happen ? Because my truck did nothing stayed running. Also I recleaned all cables again. Both batteries are 800CCA Interstate megatrons and load tested good. I recleaned the PMD ground. I am playing daddy daycare tonight so I didn't get a chance to pull the grill and unbolt PMD from bumper to plug into connector direct. Will try for that tommorow however I also did Bill H's IP test with running it up to 2000 and bringing it back down. It was fine. Consistent RPM at 2000. No surging or drop offs. Also I did what you did in the old thread and unplugged the PMD and cranked it and got 131 rpm consistently.
I let the truck sit for an hour after hot today and it took about 10-15 seconds to start which actually was normal for it. Did it again at 30 min wait from hot same result so possibly the new PMD solved the original problem because when I posted this thread the other day the truck had sat for about an hour hot and I cranked it for almost a minute and it didn't start. I'm thinking 10-15 seconds I can live ith plus it may be comb of weak glows and a weak starter. I also did a TDC relearn. Here is a fresh screen shot from todays results. BTW thanks for the tip on copy and paste. I was trying to do it with a right click menu which would not appear. The control C worked excellent. You da man.I'll be building your statue on my front lawn to worship as soon as I finish GMCTDs:lol:

Snapshot created 6/18/2008 7:08:31 PM
__________________________________________________________________
ENGINE SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Engine run time: 00:06:19
Boost pressure (MAP): 14.01 PSI
Desired EGR: 11.53 PSI
Desired idle: 562 RPM
EGR pressure: 11.53 PSI
EGR duty cycle: 39.8 %
Engine coolant temp: 188.2 F°
Engine speed: 544 RPM
Glow plug relay feedback: 0.1 Volts
Glow plug voltage: 0.2 Volts
Ignition voltage: 13.1 Volts
Wastegate duty cycle: 85.2 %

__________________________________________________________________
INFORMATION SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
PCM Calibration ID: 4805
Current DTCs: 0
Accel. ped. pos. 1: 0.57 Volts
Accel. ped. pos. 2: 4.53 Volts
Accel. ped. pos. 3: 4.1 Volts
Barometric pressure (BARO): 13.29 PSI
Battery voltage: 13.1 Volts
Fuel temperature: 114 F°
Intake air temp: 86.7 F°
Throttle position: 0 %
Turbo boost (Calculated): 0.71 PSI
Voltage reference sensor: 1.3 Volts

__________________________________________________________________
INJECTION PUMP SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Actual injection pump timing: 32.47 Deg °
Cam reference missed: 0 Counts
Crank reference missed: 0 Counts
Fuel calibration: 140 Counts
Fuel rate: 8.12 mm³
Fuel rate - Cruise: 0 mm³
Fuel rate - Idle: 7.81 mm³
Fuel rate - Maximum transient: 45 mm³
Fuel rate - Throttle requested: 0 mm³
Injection pulse width: 1.95 ms
Injection timing - Measured: 9.6 Deg °
Injection timing - Desired: 9.6 Deg °
TDC offset: 0.44 Deg °

__________________________________________________________________
TRANSMISSION SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
3-2 PWM solenoid duty cycle: 0 %
Cruise target speed: 0 MPH
Cruise speed error: 0 MPH
Current gear of transmission: 1 Gear
Current torque signal pressure: 25 PSI
Current transmission ratio: 1:4 Ratio
Error between desired and actual shift times for latest 1-2 upshift: 0 Sec
Error between desired and actual shift times for latest 2-3 upshift: 0 Sec
Force motor (PCS) - Duty cycle: 35.5 %
Force motor (PCS) - Feedback current: 0.64 Amps
Force motor (PCS) - Reference current: 0.64 Amps
Time of latest 1-2 upshift: 0 Sec
Time of latest 2-3 upshift: 0 Sec
TCC PWM solenoid duty cycle: 0 %
TCC slippage: -40 RPM
Transmission input speed: 604 RPM
Transmission output speed: 0 RPM
Transmission temperature: 146.3 F°
Turbine speed: 604 RPM
Vehicle speed: 0 MPH

__________________________________________________________________
STATUS FLAGS
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Shift lever:
Park/Neutral

Cruise control:

TCC mode word 1:
TCC is being forced off
TCC enable solenoid valid
Low threshold for COPETCC selected
Use hyst. for vehicle speed
TCC is in release mode, slipping
TCC is in locked-adjust mode
TCC is being applied
• Negative slip recently prevents apply

TCC mode word 2:
TCC PWM is on
Perform release
Perform apply
• Min. threshold occurred
TCC Bus. is valid
NDT occurs
Delay is in progress
Min. throttle occured

IOD port A:
Glow plug relay - Closed/Open
• Stepper motor inhibit - Run/Inhibit
Service Throttle Lamp - On/Off
• EGR vent enable - On/Off
• Shift A - On/Off
Shift B - On/Off
TCC enable - On/Off (4L60E only)
• Force Motor enable - On/Off

IOD SOD status register:
Coolant temp. pullup select - On/Off
Trans. temp. pullup select - On/Off
Fuel calibration temp. select - On/Off
Check Engine Lamp - On/Off
PWM1 - Reset/Normal
PWM2 - Reset/Normal
PWM3 - Reset/Normal
PWM4 - Reset/Normal

System status word:
FM shut off due to low battery
Force Motor pulse in progress
• Power is On/Off
COP2 is being serviced
Delco instrumentation PROM
• Powertrain is in motion

Discrete flags:
Brake - On/Off
A/C Compressor - Engaged/Disengaged
Power enrichment - Active/Inactive
Kickdown pattern - Active/Inactive
Four-Wheel Drive Low - Active/Inactive
Cruise low - Active/Inactive
Diagnostic - Requested/Not requested


__________________________________________________________________

 

[Acesneights1]

I just realized something. Look at the TDCO now. It's +44 after the relearn. That's bad right ? Did I do something wrong with the relearn or it that just actually what it was at and needs adjustment.

 

[JiFaire]

Oh no, Kenny... you wrecked it now.

Time for a new truck

 

[JiFaire]

just kidding

 

[Acesneights1]

Ughhhh..

 

[Acesneights1]

I just read Stephans procedure for timing set and wht I didn't do was the time set first. Is that what's screwed up or should I be hittin the snap on guy tommorow for IP wrench ?

 

[JiFaire]

89swb posted in the old place about how to make yer own IP timing tool, kenny.

here

Looks easy...

 

[Acesneights1]

So that means I have to turn it to get this thing back in spec. Did I make it worse or was it always at.44 and i just allowed the PCM to sync up with it ? Timing on these is my weak spot. I don't want to screw it up worse.