Havent, but the catalytic converter is new, could it be plugged after the cat somewhere?
Slow acceleration
08 Altima 2.5s, recently installed used engine and trans...TCM from original car but TCM reprogrammed and car ran fine. ECM from original car. New valve cover, new cat and 02 sensors.
Driven a few hundred miles now and no codes yet BUT after it gets to operating temp, acceleration from dead stop is super slow, almost non existent and then all of a sudden it gets up and goes. If I put it in park and try to Rev engine, it does so suuuper slowly. If I turn off the car and turn right back on acceleration is fine for a while and then repeats. Brake lights not on when it happens so I don't think it's the brake sensor that other have experienced.
Throttle body? Intake system? Other Ideas?
Anything is much appreciated!
Driven a few hundred miles now and no codes yet BUT after it gets to operating temp, acceleration from dead stop is super slow, almost non existent and then all of a sudden it gets up and goes. If I put it in park and try to Rev engine, it does so suuuper slowly. If I turn off the car and turn right back on acceleration is fine for a while and then repeats. Brake lights not on when it happens so I don't think it's the brake sensor that other have experienced.
Throttle body? Intake system? Other Ideas?
Anything is much appreciated!
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Yep, there's a rear cat too. It's also possible you have a plug or restriction in the fuel lines someplace north of the pump, try spraying something combustible like Brakleen or Gumout down the barrel with the top of the airbox popped. If it revs freely with supplemental fuel added, then it's still starving despite the new pump..
Gotcha, I'll have to get some. If i take the 1st O2 sensor out and it revs freely would that also be a good test for the rear cat or is that just for the manifold?Yep, there's a rear cat too. It's also possible you have a plug or restriction in the fuel lines someplace north of the pump, try spraying something combustible like Brakleen or Gumout down the barrel with the top of the airbox popped. If it revs freely with supplemental fuel added, then it's still starving despite the new pump..
Are you saying to spray in this area?
Removing the A/F will reveal a clog anyplace in the system, you're basically letting it breathe 6" away from the exhaust valves. To find out if it's the rear cat you can put the A/F back in, then either disconnect the flex pipe or remove the rear O2. If it still revs freely then the clog is someplace in back, if gets sluggish again then the front cat is clogged. Regards the fuel, yes, straight down the barrel while an assistant works the accelerator.
Back to the drawing board I go, I will look into these things. Thank you again, much appreciated.Removing the A/F will reveal a clog anyplace in the system, you're basically letting it breathe 6" away from the exhaust valves. To find out if it's the rear cat you can put the A/F back in, then either disconnect the flex pipe or remove the rear O2. If it still revs freely then the clog is someplace in back, if gets sluggish again then the front cat is clogged. Regards the fuel, yes, straight down the barrel while an assistant works the accelerator.
Removing the A/F will reveal a clog anyplace in the system, you're basically letting it breathe 6" away from the exhaust valves. To find out if it's the rear cat you can put the A/F back in, then either disconnect the flex pipe or remove the rear O2. If it still revs freely then the clog is someplace in back, if gets sluggish again then the front cat is clogged. Regards the fuel, yes, straight down the barrel while an assistant works the accelerator.
So drove it for a while til the slow acceleration started up....parked it while still running, sprayed gumout, no response still...kept it running then disconnected exhaust at the flex pipe, gunned pedal and still nothing. I also replaced MAF sensor and still slow pedal.Removing the A/F will reveal a clog anyplace in the system, you're basically letting it breathe 6" away from the exhaust valves. To find out if it's the rear cat you can put the A/F back in, then either disconnect the flex pipe or remove the rear O2. If it still revs freely then the clog is someplace in back, if gets sluggish again then the front cat is clogged. Regards the fuel, yes, straight down the barrel while an assistant works the accelerator.
Once I restart the car, acceleration runs fine for a few and then back to slow acceleration.
Any chance it's a transmission issue?
I did notice my fuel pump gauge was still acting up, showed empty, and then after restarted the car showed correct level. When I took it apart the pump the pins and plug looked fine, didn't see the burnt one you mentioned previously.
Yah, tranny is possible if it's only doing it when good and warm. If the fluid temp goes too high, the TCM will put the car in "self protection" without lighting the MIL, which also causes the ECM to limit throttle opening. If you have a 'Droid phone, you can get a bluetooth-OBD dongle and download a copy of CVTz50 to allow you to read the tranny temp. I recommend a VeePeak VP11 dongle, it's the cheapest one I know about which works 100% with CVTz50 (not all do). CVTz50 reads engine codes too, and does handy work support like IAVL and CTPL. I work at a dealership and can use Consult3+, but I still wouldn't be without CVTz50.
Is it thats something is wrong with the tranny/ or its bad that would cause high temp? Is there a fix for that short of a new tranny? I've seen some people talk about installing a secondary tranny cooler to help with this, would something as simple as that fix it?Yah, tranny is possible if it's only doing it when good and warm. If the fluid temp goes too high, the TCM will put the car in "self protection" without lighting the MIL, which also causes the ECM to limit throttle opening. If you have a 'Droid phone, you can get a bluetooth-OBD dongle and download a copy of CVTz50 to allow you to read the tranny temp. I recommend a VeePeak VP11 dongle, it's the cheapest one I know about which works 100% with CVTz50 (not all do). CVTz50 reads engine codes too, and does handy work support like IAVL and CTPL. I work at a dealership and can use Consult3+, but I still wouldn't be without CVTz50.
The QR25 gen4 Altimas mostly didn't have heat exchangers in the radiator (the VQ35's did), so they overheat easily when the fluid gets raunchy. You can tell easily if your ride has an exchanger, if the "beehive" cooler on the tranny has four tubes then it has one, if it has two tubes then the tranny has no cooling. To add a cooler to a 2-port trans you need to replace the beehive with a 4-port version. That isn't a big deal, there are tons of aftermarket 4-ports on eBay and Amazon in the $35~50 range and a good Hayden cooler can be had for around $50. The real question is whether your tranny can be saved if it has been overheating. The fluid has to be in really sad shape if it's going into protection on a constant basis. That's another thing CVTz50 can help you with, it can read the CVT-A/CVT-B values stored in the TCM, which are basically an overheat record. On a healthy trans they should both be zero, any positive number indicates the number of times the fluid has cooked. If you see big numbers then chances are the tranny is shot, if you see numbers less than about 15~20 then it's worth trying to save it with fresh fluid.
I'll have to check into that. I appreciate the info. Fluid is clear and doesn't smell burnt right now.The QR25 gen4 Altimas mostly didn't have heat exchangers in the radiator (the VQ35's did), so they overheat easily when the fluid gets raunchy. You can tell easily if your ride has an exchanger, if the "beehive" cooler on the tranny has four tubes then it has one, if it has two tubes then the tranny has no cooling. To add a cooler to a 2-port trans you need to replace the beehive with a 4-port version. That isn't a big deal, there are tons of aftermarket 4-ports on eBay and Amazon in the $35~50 range and a good Hayden cooler can be had for around $50. The real question is whether your tranny can be saved if it has been overheating. The fluid has to be in really sad shape if it's going into protection on a constant basis. That's another thing CVTz50 can help you with, it can read the CVT-A/CVT-B values stored in the TCM, which are basically an overheat record. On a healthy trans they should both be zero, any positive number indicates the number of times the fluid has cooked. If you see big numbers then chances are the tranny is shot, if you see numbers less than about 15~20 then it's worth trying to save it with fresh fluid.
If that's what's happening and it throws me into protection mode, would I still be able to drive normally? Thing is, when it does this, it accelerates super slow, but after it finally gets going it goes up and down through gears seemingly fine and can drive 70mph no problem. I come to a stop, take off same slow thing. But if I turn off and back on, it accelerates no problem for a little bit, then goes back to slow acceleration, but again after I get past that initial slow crawl I'm off and driving fine.
Depends how hot it gets. I forget the exact trip temperatures for CVT-A/CVT-B, but one simply limits the throttle opening, the other pretty much turtles the car.
So there's a nissan TSB out for the cooler issue, NTB13-079 which basically says to install one of these...do you know if this interacts with the ports that are already there on the beehive?Depends how hot it gets. I forget the exact trip temperatures for CVT-A/CVT-B, but one simply limits the throttle opening, the other pretty much turtles the car.
I recently found out that after the used trans was installed the cooler wasn't flushed.
I
You have one of the early ones with no beehive if that applies, there will be ports in the tranny case. The kits aren't as expensive as the ones requiring a beehive swap, you can find them for around $200. Not as cheap as a DIY Hayden, but it's a nuts-and-bolts mount and you don't need to screw around finding the right fittings for the ports.
Hey so I just learned upon install of used motor and trans, the data or "learned values" were not wiped clear, prior to the tcm being reprogrammed. Used tranny didn't come with tcm so original was used. Ecm is from original car.You have one of the early ones with no beehive if that applies, there will be ports in the tranny case. The kits aren't as expensive as the ones requiring a beehive swap, you can find them for around $200. Not as cheap as a DIY Hayden, but it's a nuts-and-bolts mount and you don't need to screw around finding the right fittings for the ports.
Could this be causing issues? Could there have an error in the tcm reprogram bc of this?
I remember before tcm was reprogrammed I would get no pedal response bc they said tcm didn't know what to do yet.
That positively could be causing the problem. You need to get the right IP Chars programmed in, otherwise the TCM doesn't know the right ramp of electrical current to apply to the solenoids in the VB. When they're incorrect you usually get something like the behavior you're getting, it operates but not well.
I dont have to take to nissan do i? I found a local transmission shop that said they could wipe out all data and then reprogram tcm again. When you say IP Chars programmed (not sure what that is) is that something only nissan can do, or wiping all data clear and then reprogramming tcm takes care of that?That positively could be causing the problem. You need to get the right IP Chars programmed in, otherwise the TCM doesn't know the right ramp of electrical current to apply to the solenoids in the VB. When they're incorrect you usually get something like the behavior you're getting, it operates but not well.
The IP Chars are separate from the operating program, although they're both stored on flash. The operating program may not be right either if the tranny came from a different year or model than your original, but deal with that if the IP's don't do the trick. I believe the Altie '10A's had the IP's stored on a serial EEPROM in the Valve Body like Sentras and Versas, so all that's needed is to blank the old data to force the TCM to read the VB. Some tranny shops have scanners equipped for that, so if yours claims they can do it, give it a try.
Any idea where in the scanner to go to blank the old data? Under special functions? Or another section?The IP Chars are separate from the operating program, although they're both stored on flash. The operating program may not be right either if the tranny came from a different year or model than your original, but deal with that if the IP's don't do the trick. I believe the Altie '10A's had the IP's stored on a serial EEPROM in the Valve Body like Sentras and Versas, so all that's needed is to blank the old data to force the TCM to read the VB. Some tranny shops have scanners equipped for that, so if yours claims they can do it, give it a try.
I don't know of a scanner besides the Consult3+ that will do it. Tranny shops generally have specialized equipment. Maybe someone else here knows of a generic scanner with Nissan CVT work support, but I don't. We use the C3+ at the dealership.
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