Marky Dissod
Full Access Member
Very good motor without a turbo. With ONE turbo, most excellent.
Pity GM gave up on it before trying twin turbos (or even fraternal turbos).
2008 Yukon dying.
- Thread starter SpareParts
- Start date
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Pity GM gave up on it before trying twin turbos (or even fraternal turbos).
PG01
Supporting Member
Nothing to add here except i probably blew up a dozen 231’s …. Non turbo’s …. I was a poor kid…. Thank god they were plentiful back then……Drove em like i stole em… at least 5 in my 79 monte 2 in my 83 grand prix and a few more in my 81 monte that i then swapped to a 305 with a small cam and monte ss suspension (basic f41 crap) or maybe that monte was a 4.3…. Ahh to be young, dumb and full of…… 
While I agree that the work that was done with the intake gasket replacement seems to have cured the fuel trim issue, we'd have had a better idea if we'd have seen what the fuel trims were at idle and a higher rpm. That could have pointed specifically to a vacuum leak.
I'm glad it seems to have corrected the rough running, but if more issues arise it would be interesting to follow along.
OP
OP
SpareParts
Full Access Member
It was posted.
At hot idle -14 and -16. At near wot it would move to near 0. Look at post #9
At hot idle -14 and -16. At near wot it would move to near 0. Look at post #9
Not so; only the LTFTs were there. I was asking for the SUM of the LT and ST values for each bank. They work together.
OP
OP
SpareParts
Full Access Member
Ahh, missed that i guess.
I don't know exactly what you're looking for, but i would imagine all the info is here someplace.
I don't know exactly what you're looking for, but i would imagine all the info is here someplace.
I was asking for Bank 1, and Bank 2 (separately), long-term and short-term trims at hot idle so I could add them together to arrive at the complete idle fuel trim for each bank.
And for each bank the long-term and short-term trims at 1800 or 2000 rpm so I could add those together, by bank.
Then I would compare each bank's total fuel trim at idle, vs what it is at higher rpms.
OP
OP
SpareParts
Full Access Member
Ahh yeah, Too complicated. Post #48 shows the before at hot idle, First pic.
This is what working on vehicles in this day and age has become. With shop rates and some components like transmissions so expensive..... If you can't fix it yourself the vehicle technically can become totaled quite easily due to a breakdown.
Even those of us with extensive experience dating back to the late '70s, it is a challenge at times. There is a huge learning curve to ever develop a comprehensive knowledge of every system.
That's where this forum excels. I lean towards everything mechanical that moves on the vehicle. My knowledge using the Tech 2 expands each time I use it for a different module or diagnosis, but there is so much there waiting to be learned.
If you look at all the members on the forum, you would see a vast array of different focuses on different vehicle systems. Sort of like Nick with the transmissions. He may not know the best bearing clearances to run at 800 horsepower, but he can tell you in intricate detail what every component in that transmission does and how to troubleshoot it.
Friend of mine works in the shop at the local GM dealer. It's the same scenario, they regularly consult with each other as each one has more experience with a specific system. But they're limited to only eight guys. Here on the forum you're talking hundreds if not thousands of individuals, with a knowledge base exceeding any dealer. (Daily something comes up at the local dealer where they have to inquire with GM engineers, sometimes waiting two or three days for a response)
Often, particularly with today's electronics, the trouble code doesn't even come close to giving the exact answer. As in the subject matter on this post, someone who can look at all the numbers together and know what it means... Is incredibly valuable.
This is the price we pay for manufacturers being forced to squeeze an extra couple miles per gallon, and make the engine run clean at all times to satisfy the likes of the green New deal. Personally, I don't think the cost justifies it. The time and labor spent on such complicated designs is simply insane.
LOL, my 1976 Eldorado I had in the 1980s was a lot less troublesome. That 502 ci under the hood ran flawlessly and sucked 12 miles per gallon no matter where you went. There's a lot to be said for keeping it simple
Even those of us with extensive experience dating back to the late '70s, it is a challenge at times. There is a huge learning curve to ever develop a comprehensive knowledge of every system.
That's where this forum excels. I lean towards everything mechanical that moves on the vehicle. My knowledge using the Tech 2 expands each time I use it for a different module or diagnosis, but there is so much there waiting to be learned.
If you look at all the members on the forum, you would see a vast array of different focuses on different vehicle systems. Sort of like Nick with the transmissions. He may not know the best bearing clearances to run at 800 horsepower, but he can tell you in intricate detail what every component in that transmission does and how to troubleshoot it.
Friend of mine works in the shop at the local GM dealer. It's the same scenario, they regularly consult with each other as each one has more experience with a specific system. But they're limited to only eight guys. Here on the forum you're talking hundreds if not thousands of individuals, with a knowledge base exceeding any dealer. (Daily something comes up at the local dealer where they have to inquire with GM engineers, sometimes waiting two or three days for a response)
Often, particularly with today's electronics, the trouble code doesn't even come close to giving the exact answer. As in the subject matter on this post, someone who can look at all the numbers together and know what it means... Is incredibly valuable.
This is the price we pay for manufacturers being forced to squeeze an extra couple miles per gallon, and make the engine run clean at all times to satisfy the likes of the green New deal. Personally, I don't think the cost justifies it. The time and labor spent on such complicated designs is simply insane.
LOL, my 1976 Eldorado I had in the 1980s was a lot less troublesome. That 502 ci under the hood ran flawlessly and sucked 12 miles per gallon no matter where you went. There's a lot to be said for keeping it simple
OP
OP
SpareParts
Full Access Member
Totally agree.
I made a half educated guess and it worked out fine in the end.
Drove it another 15 miles today and all still looking good, so im calling it fixed.
I made a half educated guess and it worked out fine in the end.
Drove it another 15 miles today and all still looking good, so im calling it fixed.
OP
OP
SpareParts
Full Access Member
New problem and code.
Code P1400:00 Never seen that code ever and no other codes. This code has never set on this Yukon before today.
This is part of the original complaint that i could never reproduce till a little bit ago.
Cold start, starts fine after about 10 seconds it gets rough rpm's drop and it dies. Exhaust smells rich.
Restart it a time or two and it gets warm enough to start smoothing out and everything is fine after that.
Thinking throttle body.
The original was giving a TPS sensor code, so i swapped it with an unknown used one i had here that i cleaned. I did the reset procedure.
Seems to be from research i have done that the throttle body is the most likely problem.
DTC P1400
DTC DESCRIPTOR
DTC P1400
Cold Start Emission Reduction Control System
DIAGNOSTIC FAULT INFORMATION
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
CIRCUIT/SYSTEM DESCRIPTION
The catalytic converter must be warmed to efficiently reduce the emissions. The cold start strategy is to reduce the amount of time it takes to warm the catalytic converter. During a cold start, the engine idle speed is elevated and spark timing is retarded to allow the catalyst to warm quickly. This diagnostic monitors the following to build an exhaust energy model:
- Engine speed
- Spark advance
- Throttle position
- Engine airflow
- Engine coolant temperature
- Engine runtime
- Park/neutral position
- Vehicle speed
The actual model is then compared to the expected exhaust energy model.
CONDITIONS FOR RUNNING THE DTC
- The engine is running, and a cold start has been detected.
- Vehicle speed is less than 2 km/h (1 mph).
- The engine is at idle with no input from the accelerator pedal.
- DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0201, P0202, P0203, P0204, P0205, P0206, P0300, P0335, P0336, P0351, P0352, P0353, P0501, P0502, P0506, P0507, P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P1101, P1516, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P2610 are not set.
This DTC runs for 15 seconds within the first 2 minutes of start-up. This diagnostic runs once per trip when a cold start has been determined.
CONDITIONS FOR SETTING THE DTC
The actual exhaust energy model does not match the expected exhaust energy model.
ACTION TAKEN WHEN THE DTC SETS
DTC P1400 is a Type A DTC.
CONDITIONS FOR CLEARING THE MIL/DTC
DTC P1400 is a Type A DTC.
Description and Operation
Engine Control Module Description
DIAGNOSTIC AIDS
Any loading of the engine that lowers engine RPM, such as with partial application of the clutch, A/C cycling etc., during the first 120 seconds of engine runtime may set this DTC.
CIRCUIT/SYSTEM VERIFICATION
1. Allow the engine to cool.
2. Start and idle the engine for at least 2 minutes.
3. DTC P1400 should run and pass.
CIRCUIT/SYSTEM TESTING
- Inspect the air intake system for the following:
- Damage, restriction, or modification
- Dirty or deteriorating air filter element
- Crankcase ventilation system for correct operation-Refer to Crankcase Ventilation System Inspection/Diagnosis. Component Tests and General Diagnostics
- Water intrusion
- Vacuum leak and other un-metered air downstream of the mass air flow (MAF) sensor
- Intake manifold leak
- Inspect the exhaust system for the following:
- Water intrusion
- Exhaust leak
- Damaged, restricted, modified or enhanced exhaust system-Refer to Symptoms - Exhaust System. Symptoms - Engine Exhaust
- Inspect the engine mechanical for items that could alter the air flow into the combustion chamber. Refer to Symptoms - Engine. - Symptoms - Engine Mechanical
Code P1400:00 Never seen that code ever and no other codes. This code has never set on this Yukon before today.
This is part of the original complaint that i could never reproduce till a little bit ago.
Cold start, starts fine after about 10 seconds it gets rough rpm's drop and it dies. Exhaust smells rich.
Restart it a time or two and it gets warm enough to start smoothing out and everything is fine after that.
Thinking throttle body.
The original was giving a TPS sensor code, so i swapped it with an unknown used one i had here that i cleaned. I did the reset procedure.
Seems to be from research i have done that the throttle body is the most likely problem.
DTC P1400
DTC DESCRIPTOR
DTC P1400
Cold Start Emission Reduction Control System
DIAGNOSTIC FAULT INFORMATION
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
CIRCUIT/SYSTEM DESCRIPTION
The catalytic converter must be warmed to efficiently reduce the emissions. The cold start strategy is to reduce the amount of time it takes to warm the catalytic converter. During a cold start, the engine idle speed is elevated and spark timing is retarded to allow the catalyst to warm quickly. This diagnostic monitors the following to build an exhaust energy model:
- Engine speed
- Spark advance
- Throttle position
- Engine airflow
- Engine coolant temperature
- Engine runtime
- Park/neutral position
- Vehicle speed
The actual model is then compared to the expected exhaust energy model.
CONDITIONS FOR RUNNING THE DTC
- The engine is running, and a cold start has been detected.
- Vehicle speed is less than 2 km/h (1 mph).
- The engine is at idle with no input from the accelerator pedal.
- DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0201, P0202, P0203, P0204, P0205, P0206, P0300, P0335, P0336, P0351, P0352, P0353, P0501, P0502, P0506, P0507, P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P1101, P1516, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P2610 are not set.
This DTC runs for 15 seconds within the first 2 minutes of start-up. This diagnostic runs once per trip when a cold start has been determined.
CONDITIONS FOR SETTING THE DTC
The actual exhaust energy model does not match the expected exhaust energy model.
ACTION TAKEN WHEN THE DTC SETS
DTC P1400 is a Type A DTC.
CONDITIONS FOR CLEARING THE MIL/DTC
DTC P1400 is a Type A DTC.
Description and Operation
Engine Control Module Description
DIAGNOSTIC AIDS
Any loading of the engine that lowers engine RPM, such as with partial application of the clutch, A/C cycling etc., during the first 120 seconds of engine runtime may set this DTC.
CIRCUIT/SYSTEM VERIFICATION
1. Allow the engine to cool.
2. Start and idle the engine for at least 2 minutes.
3. DTC P1400 should run and pass.
CIRCUIT/SYSTEM TESTING
- Inspect the air intake system for the following:
- Damage, restriction, or modification
- Dirty or deteriorating air filter element
- Crankcase ventilation system for correct operation-Refer to Crankcase Ventilation System Inspection/Diagnosis. Component Tests and General Diagnostics
- Water intrusion
- Vacuum leak and other un-metered air downstream of the mass air flow (MAF) sensor
- Intake manifold leak
- Inspect the exhaust system for the following:
- Water intrusion
- Exhaust leak
- Damaged, restricted, modified or enhanced exhaust system-Refer to Symptoms - Exhaust System. Symptoms - Engine Exhaust
- Inspect the engine mechanical for items that could alter the air flow into the combustion chamber. Refer to Symptoms - Engine. - Symptoms - Engine Mechanical
OP
OP
SpareParts
Full Access Member
Put a new TB on it and first cold start yesterday was a little rough to start with but did not die and smoothed out.
Cold start this morning and it was pretty smooth running and seems to be working good. Fingers crossed!
Cold start this morning and it was pretty smooth running and seems to be working good. Fingers crossed!
