Lost on stuttering problem

[nickk90]

I'm at a loss with a stuttering and bucking problem with my car. It only happens during cruise/light load conditions. My wideband will spike rich and lean and stumble really bad. WOT no problems at all.

So far I have changed plugs , wires , o2 sensor and cleaned my MAF.

NGK brp6s gapped to .028 and NGK wires

I had a Bosch o2 sensor and saw a lot off people had problems with them so I swapped it out for a Denso

My coil pack checks out fine

Right now I think it has to be my MAF but I also read somewhere that a dirty EGR valve could cause there symptoms . My car was burning alot of oil form bad valve stem seals but they are now replaces so I imagine that could of cause a lot of build up in the ERG valve.

Any opinions on other things to check out ? I'm at a lose

No one has any ideas or suggestions?

 

[Pyros95GSX]

I'm also getting the error code p1500 something bout generator problem or something like that. and said also might be a prob with the ecu. so i just found that and took it out but i dont see any burnt spots on the board or anything like that it looks perfectly fine. it said it was overcharging so it couldnt be my alternator affecting the performance like that could it?

could a bad ground be the problem also? as the ecu wasnt bolted down to anything when i took it out i jus had to unplug the connectors. and the ground wire on my battery doesnt look the best shape either but it is connected. also when i drove the car 2day it never done the problem. it was running great actually. I was also going to start a new page but i cnt figure out how? any advice on that?

 

[luv2rallye]

The TB hole you mentioned is sealed off and doesn't do anything.

P1500 is either the alt harness connector, or the alt itself, or the ECU.

Yes bad grounds can result in any type of electrical problem. Check them and replace that battery negative (B-) cable if it's bad. You should have 2 separate cables on B-: one to the body firewall and 1 to a starter mounting bolt on bell housing. You should also have a 1" wide braided flat flexible cable from intake mainfold to the firewall.

ECU doesn't absolutely have to be bolted down but the case is a ground connection and it will be better if it's bolted to chassis.

And with ECU unplugged, the harness side pin 92 (sensor signal ground) must NOT have continuity to ground. It must ONLY be connected to ground THROUGH the ECU (another reason ECU case should be grounded).

 

[Pyros95GSX]

Ok i replaced my positive terminal with a better one. my batt wasnt being held down so i got a kit for that and i replaced my ground to frame wire. well all day it's been doing great i was almost positive it was my alt with all the oil residue on it. but i'mma keep driving it and hope for the best. but today it was driving like a totally diffrent car. all i can say is damn dsm's are tough!!! and about the ecu being bolted in i cant find anywhere to bolt it really but i did notice a 12v remote wire from my stero that the electrical tape had come off and it was on the ecu so i fixed that also. anyways thanx 4 all the advice rally I'm deffinatley going to do that boost leak test done this weekend.

Ok it's still doing it. I have no clue what it could be. but it's not doing it as much now so thats a good thing. i had my alt checked and they said it was fine. thinking bout rplacing the fuel pump with a walbro or something. dont really know what to do or try.

 

[luv2rallye]

Know that auto stores do very poor and incomplete testing of alts and in my opinion (and a lot of others on here that took them there) it's totally worthless. To properly and completely test an alternator it should be brought in to an alternator/starter repair shop - not an auto store which only tests go/no go output voltage (and they more than half the time will say it's good when it's not and won't output properly in your car). The alt shop will test for too high AC voltage, max current draw, bad diodes/regulator, thermal, short protection, low & hi speed operation, current drain while spinning and not, bad bearings/brushes, and a dozen other things which no auto store can/will do. And all this is usually for free. Also they are the experts since that is their specialty.

For my $.02 on auto store alts: http://www.dsmtuners.com/forums/newbie-forum/263621-alternator-output-problems.html#post151468330.

Here's a way you can test the battery/alt yourself (sometimes a bad battery will make the alt appear bad) to see if you should bring it to an alt repair shop for further testing/repair or just go buy a new one if you don't want to bother with that: http://www.dsmtuners.com/forums/new...reeway-electrical-problems.html#post151165661.

 

[Pyros95GSX]

just as a lil update my car has been running great for the past 2 weeks i am still using a lot of fuel. about 200 miles from a full tank but it's prob got a lot to do with my driving. but I mean who can resist hearing that turbo spool up?

 

[Pyros95GSX]

Ok it's doing it again, still havent had the chance to get a BLT done. i dont understand how it stoped for the longest time and now its back to doing it again. Makes me not even want to drive it. Would it be easier to just get a new TB? i guess the first thing i need to get done is a BLT.

 

[Pyros95GSX]

Did a boost leak test and yep i have a bad TB leak. i got my TB off and tryed getting it apart but one of the screws holding the TP in striped out. anyway to save some trouble i was wondering if anyone knows of a good throttle body as a replacement. i think thats going to be easier for me to do and replace than keep messing with this thing.