hello lt1 help
Thread Starter
Registered User
Joined: Jun 2022
Posts: 19
hello lt1 help
Hello to all. I’m 77, have trouble typing, and not good on computer, few little strokes.
I have a 1995 LT1 engine and PCM from a Camaro, put it a 1957 GMC pickup. I have a Dakota Digital dash and 700r4 trans, PCM were done in USA and one in Alberta, Canada.
Now the fun starts. It has a Painless wiring harness in it. PCM was done (tuned?). I got it running. When starting cold it runs great, but after 10 to 15 minutes running it shuts down. running rough before the shut down. If I can get it to start again it runs like a POS. But leave it for 1/2 hour and it starts again and runs great until it shuts down again.
Installed new fuel pump, pressure is 42 PSI. Replaced Opti, ICM, MAF, O2 sensor, coolant temp sensor in water pump (ECT). If I unplug ECT and hook up a spare sensor and lay on engine it runs great. I talked to Rob/Shoebox and he said I should probably get a scanner on it to look for abnormalities. Could be a coolant sensor giving wrong data or numerous other things. Try laptop and free software like Scan9495 and all you need to buy is a cable.
Rob sent me here to talk to Fred/Injuneer. I didn’t have a right side O2 sensor, so I had to install one. Got Scan9495 and cable and have some scans but I don’t understand them.
Unable to decipher the following:
it has 2.2 ohms at todays temp in hand 80 {f} in motor it has 2.7 volt at 110 temp 650 ohms , then 1.7 ohms 100 temp 3.3 volts. then .700ohms 3.1 volts 110temp. pcm wire digram saids 2.2 with key on and 2.3 run
I hope I did this right.
Thank you, Doug
NOTE from Admin: I told Doug I would edit this for him, to make it clearer.
I have a 1995 LT1 engine and PCM from a Camaro, put it a 1957 GMC pickup. I have a Dakota Digital dash and 700r4 trans, PCM were done in USA and one in Alberta, Canada.
Now the fun starts. It has a Painless wiring harness in it. PCM was done (tuned?). I got it running. When starting cold it runs great, but after 10 to 15 minutes running it shuts down. running rough before the shut down. If I can get it to start again it runs like a POS. But leave it for 1/2 hour and it starts again and runs great until it shuts down again.
Installed new fuel pump, pressure is 42 PSI. Replaced Opti, ICM, MAF, O2 sensor, coolant temp sensor in water pump (ECT). If I unplug ECT and hook up a spare sensor and lay on engine it runs great. I talked to Rob/Shoebox and he said I should probably get a scanner on it to look for abnormalities. Could be a coolant sensor giving wrong data or numerous other things. Try laptop and free software like Scan9495 and all you need to buy is a cable.
Rob sent me here to talk to Fred/Injuneer. I didn’t have a right side O2 sensor, so I had to install one. Got Scan9495 and cable and have some scans but I don’t understand them.
Unable to decipher the following:
it has 2.2 ohms at todays temp in hand 80 {f} in motor it has 2.7 volt at 110 temp 650 ohms , then 1.7 ohms 100 temp 3.3 volts. then .700ohms 3.1 volts 110temp. pcm wire digram saids 2.2 with key on and 2.3 run
I hope I did this right.
Thank you, Doug
NOTE from Admin: I told Doug I would edit this for him, to make it clearer.
Administrator
Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: hello lt1 help
I opened a few of the files, and they all seemed to be of the engine idling or of the key in "run" but the engine not running. You need to run a single, long, continuous data log per post #2 in this thread:
https://www.camaroz28.com/forums/com...-guide-886891/
DATA LOG GUIDELINES
- Do not reset PCM. Do not remove a battery cable. Do not pull the PCM BAT fuse.
- Start COLD engine. Do NOT turn on A/C or Defrost. Turn off traction control (ASR / TCS) if vehicle equipped.
- Leave the accel pedal alone. Do NOT rev the engine while it is warming up. Don't drive it. Leave it alone.
- Allow engine to idle for at least 4 minutes. Should be long enough to warm up and put PCM in closed loop.
- Start driving car for about 5-10 minutes. Vary the accel pedal position and RPM. Make at least one WOT pull from a roll up to at least 5,000 RPM.
- Mentally note (or have a passenger write down)when the engine exhibited the problem you are chasing.
- Stop driving, let it idle for about 30 seconds, without touching the accel pedal.
Finished.
Post your .csv format log as an attachment to a post in the active thread addressing your problem. Do not upload it to a 3rd party site.
You do not need to run the transmission log since you are using a 700R4. The PCM is trying to control an electronic 4L60E. That should have been programmed out of your PCM. Appears the right bank O2 sensor is functioning in later files.
https://www.camaroz28.com/forums/com...-guide-886891/
DATA LOG GUIDELINES
- Do not reset PCM. Do not remove a battery cable. Do not pull the PCM BAT fuse.
- Start COLD engine. Do NOT turn on A/C or Defrost. Turn off traction control (ASR / TCS) if vehicle equipped.
- Leave the accel pedal alone. Do NOT rev the engine while it is warming up. Don't drive it. Leave it alone.
- Allow engine to idle for at least 4 minutes. Should be long enough to warm up and put PCM in closed loop.
- Start driving car for about 5-10 minutes. Vary the accel pedal position and RPM. Make at least one WOT pull from a roll up to at least 5,000 RPM.
- Mentally note (or have a passenger write down)when the engine exhibited the problem you are chasing.
- Stop driving, let it idle for about 30 seconds, without touching the accel pedal.
Finished.
Post your .csv format log as an attachment to a post in the active thread addressing your problem. Do not upload it to a 3rd party site.
You do not need to run the transmission log since you are using a 700R4. The PCM is trying to control an electronic 4L60E. That should have been programmed out of your PCM. Appears the right bank O2 sensor is functioning in later files.
Administrator
Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: hello lt1 help
The data from testing the coolant temp sensor in the water pump is unclear. To measure the resistance unplug the connector and probe the two pins on the sensor. The approximate resistance should be:
80-degF - 2,600 ohms
100-degF - 1,600 ohms
110-degF - 1,280 ohms
Don't worry about volts.
Looking at one of the data logs, the engine has been running for 25 minutes, but the coolant temp shows as 100-degF. As a result, the left bank O2 sensor (right side apparently had not been installed yet) is over 0.900 volts, indicating a very rich mixture. The coolant temp is actually lower than the intake air temp (108-degF). Something wrong there.
You indicate you have a spare coolant temp sensor. Test that by immersing it in a bowl of water and ice - should read 9,420 ohms. Then immerse it in boiling water, should read 177 ohms (assuming your location elevation is at or near sea level). Make sure you have the ohm meter set to the correct scale.
80-degF - 2,600 ohms
100-degF - 1,600 ohms
110-degF - 1,280 ohms
Don't worry about volts.
Looking at one of the data logs, the engine has been running for 25 minutes, but the coolant temp shows as 100-degF. As a result, the left bank O2 sensor (right side apparently had not been installed yet) is over 0.900 volts, indicating a very rich mixture. The coolant temp is actually lower than the intake air temp (108-degF). Something wrong there.
You indicate you have a spare coolant temp sensor. Test that by immersing it in a bowl of water and ice - should read 9,420 ohms. Then immerse it in boiling water, should read 177 ohms (assuming your location elevation is at or near sea level). Make sure you have the ohm meter set to the correct scale.
Administrator
Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: hello lt1 help
- Just keep in mind….. testing the spare sensor, uninstalled is just to insure you are using the multimeter correctly.
- After that, you need to redo the test of the sensor that is in the water pump housing, WHILE IT IS STILL INSTALLED.
- To test the currently installed sensor, test it while the coolant is cold, BEFORE starting the engine. Note the ambient air temp so we can approximate the coolant temp. That will .give you a low temperature reference. Then start the engine and let it idle. When the dash gauge hits the 180°F hash mark, shut the engine down before unplugging the sensor, then test resistance again. If the gauge doesn’t reach 180° mark after a reasonable period of time shut it down and check the sensor resistance anyway. That will give us a high temp resistance.
Running a data log as I outlined will tell us what temperature the PCM is seeing from the sensor. Start engine COLD, let it idle for 4 minutes before driving it. Then drive it normally until the problem appears. No need to make a full throttle pull to 5,000 RPM. You start the logging shortly BEFORE you start the engine, and keep the log going until the problem appears.
Thread Starter
Registered User
Joined: Jun 2022
Posts: 19
Re: hello lt1 help
ok this is what i got 74-deg-2491 ohms
100-deg-8470 ohms
110-deg-7350 ohms
cold 5min in freeze 5900 ohms
file from run
ect reading in engine still littlte warm 140-8800 ohms run up to 180 -3200 ohms . mt temps are in {F}
100-deg-8470 ohms
110-deg-7350 ohms
cold 5min in freeze 5900 ohms
file from run
ect reading in engine still littlte warm 140-8800 ohms run up to 180 -3200 ohms . mt temps are in {F}
Last edited by jertho; Jun 27, 2022 at 06:04 PM.
Administrator
Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: hello lt1 help
Are the first 4 results above for the “spare” temperature sensor? They make no sense at all. The temp sensor is a “thermistor” - as temperature goes up, sensor resistance goes down. Compare those results to the temp vs. resistance chart in Shoebox’s link: Most of your readings are not even close to the chart values.
4th Gen LT1 F-body Tech Articles
Is the “spare” sensor new or used? Are you sure it is the correct part # for 2-pin temp sensor for a GM vehicle?
And is the last line for the sensor in the water pump?
In the chart, 8,800 ohms corresponds to about 34°F (not 140°). 3,200 ohms corresponds to about 74°F (not 180°).
If those numbers for the old sensor in the water pump are accurate, it would certainly explain why the engine runs poorly when it warms up.
I'll take a quick look at the data log in the morning.
4th Gen LT1 F-body Tech Articles
Is the “spare” sensor new or used? Are you sure it is the correct part # for 2-pin temp sensor for a GM vehicle?
And is the last line for the sensor in the water pump?
In the chart, 8,800 ohms corresponds to about 34°F (not 140°). 3,200 ohms corresponds to about 74°F (not 180°).
If those numbers for the old sensor in the water pump are accurate, it would certainly explain why the engine runs poorly when it warms up.
I'll take a quick look at the data log in the morning.
Registered User
Joined: Jul 2019
Posts: 191
From: Duvall, WA
Re: hello lt1 help
Because from what i see in your computer log, the temp sensor is reading okay, you can see when the thermostat opens and closes!
Administrator
Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: hello lt1 help
Agree…. no problem with the coolant temp sensor. Starts cold at 98°F and gradually warms up to 195-200°F.
However, there is a DTC 14 for the coolant temp sensor - low voltage/high temperature. Must be a “stored” code from a previous event.
Total of 8 codes including the coolant temp sensor.. 4 of them are for the transmission, because he has a 700R4 instead of a 4L60E. Trans should be removed from the PCM.
DTC 18 - injector fault
DTC 26 - EVAP purge solenoid (does the transplanted engine even have a charcoal canister?)
DTC 27 - EGR vacuum solenoid (does the transplanted engine even have an EGR system?)
TWO ACTIONS:
- Reset PCM/clear codes by pulling “PCM BAT” fuse for 30 seconds
- Rerun data log
QUESTION: The log is 11.5 minutes long. Does it end at the point the engine started running rough and stalled - the problem we are trying to solve?
IN THE FUTURE:
Have PCM reprogrammed to delete non-existent systems, trans
However, there is a DTC 14 for the coolant temp sensor - low voltage/high temperature. Must be a “stored” code from a previous event.
Total of 8 codes including the coolant temp sensor.. 4 of them are for the transmission, because he has a 700R4 instead of a 4L60E. Trans should be removed from the PCM.
DTC 18 - injector fault
DTC 26 - EVAP purge solenoid (does the transplanted engine even have a charcoal canister?)
DTC 27 - EGR vacuum solenoid (does the transplanted engine even have an EGR system?)
TWO ACTIONS:
- Reset PCM/clear codes by pulling “PCM BAT” fuse for 30 seconds
- Rerun data log
QUESTION: The log is 11.5 minutes long. Does it end at the point the engine started running rough and stalled - the problem we are trying to solve?
IN THE FUTURE:
Have PCM reprogrammed to delete non-existent systems, trans
Administrator
Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: hello lt1 help
Another thing I noticed - both coolant fans turn on prematurely (well below the factory programmed “on” temperatures). Is the a manual fan switch or possibly an aftermarket fan temp turn on device?
Thread Starter
Registered User
Joined: Jun 2022
Posts: 19
Re: hello lt1 help
Agree…. no problem with the coolant temp sensor. Starts cold at 98°F and gradually warms up to 195-200°F.
However, there is a DTC 14 for the coolant temp sensor - low voltage/high temperature. Must be a “stored” code from a previous event.
Total of 8 codes including the coolant temp sensor.. 4 of them are for the transmission, because he has a 700R4 instead of a 4L60E. Trans should be removed from the PCM.
DTC 18 - injector fault
DTC 26 - EVAP purge solenoid (does the transplanted engine even have a charcoal canister?) { no charcoal canister]
DTC 27 - EGR vacuum solenoid (does the transplanted engine even have an EGR system?) { no EGR system ]
TWO ACTIONS:
- Reset PCM/clear codes by pulling “PCM BAT” fuse for 30 seconds { will do }
- Rerun data log
QUESTION: The log is 11.5 minutes long. Does it end at the point the engine started running rough and stalled - the problem we are trying to solve? {yes engine started running rough and stalled }
IN THE FUTURE:
Have PCM reprogrammed to delete non-existent systems, trans
However, there is a DTC 14 for the coolant temp sensor - low voltage/high temperature. Must be a “stored” code from a previous event.
Total of 8 codes including the coolant temp sensor.. 4 of them are for the transmission, because he has a 700R4 instead of a 4L60E. Trans should be removed from the PCM.
DTC 18 - injector fault
DTC 26 - EVAP purge solenoid (does the transplanted engine even have a charcoal canister?) { no charcoal canister]
DTC 27 - EGR vacuum solenoid (does the transplanted engine even have an EGR system?) { no EGR system ]
TWO ACTIONS:
- Reset PCM/clear codes by pulling “PCM BAT” fuse for 30 seconds { will do }
- Rerun data log
QUESTION: The log is 11.5 minutes long. Does it end at the point the engine started running rough and stalled - the problem we are trying to solve? {yes engine started running rough and stalled }
IN THE FUTURE:
Have PCM reprogrammed to delete non-existent systems, trans
Thread Starter
Registered User
Joined: Jun 2022
Posts: 19
Re: hello lt1 help
{ factory programmed pcm no switch wired from shbox site}
Last edited by jertho; Jun 28, 2022 at 11:45 PM.
Administrator
Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: hello lt1 help
Then what does “PCM were done in USA and one in Alberta, Canada”?
You have to read what I write very carefully, and answer all the questions.
- does the truck have a functioning EVAP charcoal canister, with purge controlled by PCM?
- does the engine have a functioning EGR system, controlled by the PCM?
- at the end of the 11.5 minute long data log, did the engine begin to run rough and stall?
Are you planning to clear the codes from the PCM and run the log again as I requested?
Reprogramming the PCM is a FUTURE task. Let’s leave a referral on who can do it until later.
PLEASE read what I write and answer the questions. This is where I can’t keep spending time working on these data logs, and the whole thing breaks down. This is why I have (until you requested my help) stopped reviewing these data logs for people.
You have to read what I write very carefully, and answer all the questions.
- does the truck have a functioning EVAP charcoal canister, with purge controlled by PCM?
- does the engine have a functioning EGR system, controlled by the PCM?
- at the end of the 11.5 minute long data log, did the engine begin to run rough and stall?
Are you planning to clear the codes from the PCM and run the log again as I requested?
Reprogramming the PCM is a FUTURE task. Let’s leave a referral on who can do it until later.
PLEASE read what I write and answer the questions. This is where I can’t keep spending time working on these data logs, and the whole thing breaks down. This is why I have (until you requested my help) stopped reviewing these data logs for people.
Thread Starter
Registered User
Joined: Jun 2022
Posts: 19
Re: hello lt1 help
the pcm were sent away to have vats and all emissions remove they had stranded transmission in the car there were told what trans i was running., tune left stock.
the truck does not have evap charcoal canister. purge controlled by pcm i.dont know should have being remove
the engine does not have functioning egr system , controlled by pcm i.dont know should have being remove
yes i will clear codes and run test again
thank you again doug
the truck does not have evap charcoal canister. purge controlled by pcm i.dont know should have being remove
the engine does not have functioning egr system , controlled by pcm i.dont know should have being remove
yes i will clear codes and run test again
thank you again doug