Bogging under light acceleration help!
#22
07-21-2017, 03:11 PM
I replaced the map 2 years ago. The car has 138,000 miles on it maybe it's time for me to give in and treat it to a new fuel pump I had the fuel pressure tested and it was 42 at idle with the fpr hose attached
#23
07-21-2017, 03:33 PM
#25
07-21-2017, 06:41 PM
Putting my two cents in here.
First of all, I agree with all of the previous posts and suggestions.
Let me offer a few other things to check...
1. It's a common problem for brand new PCV's to not come with an o-ring. Without it everything the MAF and MAP data is effected. It might be worth taking 10 minutes/$10 to change and/or check the PCV. Here's a excerpt from a post on another forum that explains the situation well:
What many don't realize is, the pcv on a 3800 series 2, is calibrated into the maf sensor/map sensor/throttle body system.
the "inlet" for the pcv is in the throttle body, downstream from the maf sensor, so all the pcv air is sensed and monitored as it enters the engine past the maf sensor. it then makes a 90 degree turn in the throttle body, and goes straight down through the lower intake manifold into the crankcase. from there it goes through the engine, up the other side into the upper intake manifold below the map sensor, then into the upper plenum, to be mixed with the fuel via the pcv/map suction pipe inside the upper plenum. if you have the throttle body off and look inside the plenum, you can see the hose inside hanging there.
Here's a link to the thread:
PCV valve missing o-ring, blown oil pan gasket - 3800Pro.com Forum
First of all, I agree with all of the previous posts and suggestions.
Let me offer a few other things to check...
1. It's a common problem for brand new PCV's to not come with an o-ring. Without it everything the MAF and MAP data is effected. It might be worth taking 10 minutes/$10 to change and/or check the PCV. Here's a excerpt from a post on another forum that explains the situation well:
What many don't realize is, the pcv on a 3800 series 2, is calibrated into the maf sensor/map sensor/throttle body system.
the "inlet" for the pcv is in the throttle body, downstream from the maf sensor, so all the pcv air is sensed and monitored as it enters the engine past the maf sensor. it then makes a 90 degree turn in the throttle body, and goes straight down through the lower intake manifold into the crankcase. from there it goes through the engine, up the other side into the upper intake manifold below the map sensor, then into the upper plenum, to be mixed with the fuel via the pcv/map suction pipe inside the upper plenum. if you have the throttle body off and look inside the plenum, you can see the hose inside hanging there.
Here's a link to the thread:
PCV valve missing o-ring, blown oil pan gasket - 3800Pro.com Forum
Last edited by plumbob; 07-21-2017 at 07:15 PM.
#26
07-21-2017, 06:46 PM
Putting my two cents in here.
First of all, I agree with all of the previous posts and suggestions.
Let me offer a few other things to check...
1. It's a common problem for brand new PCV's to not come with an o-ring. Without it everything the MAF and MAP data is effected. It might be worth taking 10 minutes/$10 to change and/or check the PCV. Here's a excerpt from a post on another forum that explains the situation well:
What many don't realize is, the pcv on a 3800 series 2, is calibrated into the maf sensor/map sensor/throttle body system.
the "inlet" for the pcv is in the throttle body, downstream from the maf sensor, so all the pcv air is sensed and monitored as it enters the engine past the maf sensor. it then makes a 90 degree turn in the throttle body, and goes straight down through the lower intake manifold into the crankcase. from there it goes through the engine, up the other side into the upper intake manifold below the map sensor, then into the upper plenum, to be mixed with the fuel via the pcv/map suction pipe inside the upper plenum. if you have the throttle body off and look inside the plenum, you can see the hose inside hanging there.
Here's a link to the thread:
PCV valve missing o-ring, blown oil pan gasket - 3800Pro.com Forum
2. If I'm not mistaken, 42 psi is a bit low on the FP. As I recall 48-50 is normal.
First of all, I agree with all of the previous posts and suggestions.
Let me offer a few other things to check...
1. It's a common problem for brand new PCV's to not come with an o-ring. Without it everything the MAF and MAP data is effected. It might be worth taking 10 minutes/$10 to change and/or check the PCV. Here's a excerpt from a post on another forum that explains the situation well:
What many don't realize is, the pcv on a 3800 series 2, is calibrated into the maf sensor/map sensor/throttle body system.
the "inlet" for the pcv is in the throttle body, downstream from the maf sensor, so all the pcv air is sensed and monitored as it enters the engine past the maf sensor. it then makes a 90 degree turn in the throttle body, and goes straight down through the lower intake manifold into the crankcase. from there it goes through the engine, up the other side into the upper intake manifold below the map sensor, then into the upper plenum, to be mixed with the fuel via the pcv/map suction pipe inside the upper plenum. if you have the throttle body off and look inside the plenum, you can see the hose inside hanging there.
Here's a link to the thread:
PCV valve missing o-ring, blown oil pan gasket - 3800Pro.com Forum
2. If I'm not mistaken, 42 psi is a bit low on the FP. As I recall 48-50 is normal.
#27
07-21-2017, 07:33 PM
That's a tough one for sure. 0/0 on the STFT/LTFT rules out a vacuum leak or fuel mix problem. Starting to sound electrical since you've covered the fuel system. What brand plugs and wires were installed? Our cars seem to prefer ACDelco Irridium or NGK Platinum plugs, and ACDelco or Bosch wires.
FYI I had to check the FP norm and 42 psi is OK.
FYI I had to check the FP norm and 42 psi is OK.
#28
07-21-2017, 07:38 PM
Thanks for looking into that and I just put some acdelco iridium plugs in after ngks. Also you reminded me that I had a ground wire attached to my airbox that wasn't ground properly it was loose during that one drive the car ran fine, I made sure that ground connection was nice and solid and now it seems like the bogging is worse, I'm at a loss
#29
07-21-2017, 07:56 PM
Have you tried jiggling and or disconnecting that wire while running to check for differences?
I'm no auto-electric expert, but as I understand these cars are wired in a way that if a ground is lost in one area the system looks for another source which can effect function of other systems. One of our electrical expert members would come in handy here.
I'm no auto-electric expert, but as I understand these cars are wired in a way that if a ground is lost in one area the system looks for another source which can effect function of other systems. One of our electrical expert members would come in handy here.
#30
07-21-2017, 07:59 PM
Have you tried jiggling and or disconnecting that wire while running to check for differences?
I'm no auto-electric expert, but as I understand these cars are wired in a way that if a ground is lost in one area the system looks for another source which can effect function of other systems. One of our electrical expert members would come in handy here.
I'm no auto-electric expert, but as I understand these cars are wired in a way that if a ground is lost in one area the system looks for another source which can effect function of other systems. One of our electrical expert members would come in handy here.