Leo98 Posted May 5, 2014 Share Posted May 5, 2014 I have been reading and trying to figure out on my own but now i need help. What the rig is doing is when i decelerate to slow to a stop and sit at a light the engine wants to die, it will drop to almost 0 rpm then I put my foot on the brake and rev the engine while holding the brake so it doesn't die. I can get it to even out after a few seconds of revving and then it will idle by itself. No problems that i can feel when in motion, only at stops. Sometimes before i take off it drops really low and then chugs forward and catches, then goes fine until it wants to act up again. So far i have taken the IACV off, cleaned and tested it by plugging back in and turning the ignition on and i can see the plunger move. I tested with OHM meter and was 0.00, I cleaned the throttle body, replaced the PCV valve while i had the intake off. I did spark plugs, wires, cap, rotor, oil, oil filter, air filter, fuel filter a couple months ago and has been running fine. The current problem is frustrating because i went to AutoZone and there was 0 codes. Could it be a distributor trying to fail? TPS? Thanks, i need some ideas or experience with this issue, please. Link to comment Share on other sites More sharing options...
SpecialWarr Posted May 5, 2014 Share Posted May 5, 2014 The other usual suspects are the Fuel Pressure Regulator and the bad ground on the MAF. It seems to me that the IACV is supposed to be between 70-80 ohms. You might want to check that again. Not that I'm a mechanic or pathy expert! sent from under Ernest the Pathfinder Link to comment Share on other sites More sharing options...
Leo98 Posted May 5, 2014 Author Share Posted May 5, 2014 Damn you are right, i went back and reread the instructions and i did do the test wrong, i didn't touch the leads to the right terminals. But now i watched a youtube video and the title was "how to tell if your idle air control is going bad" If that were the case then is that what is happening to mine, it's getting ready to fail? Would that be why i don't have any codes for it? Link to comment Share on other sites More sharing options...
Precise1 Posted May 5, 2014 Share Posted May 5, 2014 Leo, have you downloaded the Factory Service Manual from the pinned thread in the Garage section? It has a whole diagnostic section (EC I believe) based purely on symptoms, not just OBD2 codes, things like rough and low idle. That is where I would start... B 1 Link to comment Share on other sites More sharing options...
Leo98 Posted May 5, 2014 Author Share Posted May 5, 2014 Yes...I discovered it yesterday :lmao:and now going through the testing check list. I started today with spraying the MAF sensor with the appropriate cleaner. After reinstalling and starting i went to back out and it wanted to die, i let it rev for a sec and put into gear and not a hiccup since getting home a few miles down the road. I have another errand farthr later and that will tell me if it worked...Thanks Link to comment Share on other sites More sharing options...
Leo98 Posted May 7, 2014 Author Share Posted May 7, 2014 Update: I tried to clean the MAF sensor but it was to far gone, i ended up replacing it and right before i did the check engine soon light came on, with a MAF sensor code. Running smooth but engine light is still on pointing to the MAF sensor code. Will it reset on it's own? Thanks for all the advice and tips. Link to comment Share on other sites More sharing options...
Precise1 Posted May 7, 2014 Share Posted May 7, 2014 I do not know if it will reset on its own, perhaps after a number of ignition cycles without error input? The best way is to simply use an OBD2 reader, plug it in and read/clear the codes. B Link to comment Share on other sites More sharing options...
byob Posted May 8, 2014 Share Posted May 8, 2014 (edited) I cringe when I hear people cleaning mas. The "hot wire" is very sensitive and is even affected by air flow. Need to check the voltage and gps. Nissan has ground problems among other things. Off the top of my head I am not sure how many key cycles it takes to erase dtc's. Try disconnecting the battery and taking the pos and neg cable ends and touch them together to fully discharge the system. That should erase the failed dtc but also will reset your srt's. Edited May 8, 2014 by byob Link to comment Share on other sites More sharing options...
Leo98 Posted May 8, 2014 Author Share Posted May 8, 2014 I knew I would be buying a new so I figured I would try the cleaning first, just to see what it would do. I also decided to buy new battery terminal connectors, so I had the battery disconnected for about 30 min; I clamped down the connectors and started right up with no more check engine soon light on. Link to comment Share on other sites More sharing options...
Slartibartfast Posted May 8, 2014 Share Posted May 8, 2014 I cleaned my MAF with contact cleaner (no residue) and a Q tip, and while I noted no performance improvement (it didn't look that dirty to begin with), it didn't seem to hurt anything. Anyway, the dying at stoplights sounds familiar, because I've fought a similar issue with mine a couple times. I think I've tracked it down to a corroded plug for the coolant temperature sensor causing weird inputs to the computer. Both times it's acted up, messing with the MAF/TPS/CTS plugs put it right again, and the coolant sensor plug was the only one of those that looked questionable inside. It's the rearmost one on the coolant neck, by the distributor, assuming the VG30/33 sensors are in the same places. Pulling the two plug wires nearest to it out of the distributor makes accessing the plug (and that little wire clip that holds it in) a lot easier. That said, you say you can make yours even out by revving it, and nothing seems to even mine out when it's acting up (besides a foot on the gas). That might suggest a different issue. Still wouldn't hurt to clean that connection, though. Link to comment Share on other sites More sharing options...
Precise1 Posted May 8, 2014 Share Posted May 8, 2014 I cringe when I hear people cleaning mas. The "hot wire" is very sensitive and is even affected by air flow. Yes, it is delicate, but they do need cleaning sometimes. Some people have reported issues with MAF sensor cleaner as well; I've personally cleaned at least 1/2 dozen sensors on WD21s and R50s with a Q-tip and isopropyl alcohol without issue. Just be gentle... B Link to comment Share on other sites More sharing options...
byob Posted May 8, 2014 Share Posted May 8, 2014 I understand the attempt to better the performance by cleaning the mas. Working for Nissan for 31 years and I have never cleaned a mas. I have seen the adverse affects of those who try. I have seen kn filters with too much oil kill a mas. On 90-96 300z's I have seen kn filters with the seam in the wrong position affect the mas. I will stay on the manufactures side and quote a non serviceable part Link to comment Share on other sites More sharing options...
Leo98 Posted May 8, 2014 Author Share Posted May 8, 2014 When i bought my Pathfinder 3 months ago I noticed the MAF sensor housing had a crack/hole in the top of it. I didn't think the housing being cracked would have an effect on it by thinking it was a sealed unit and was just a housing case, but here i am 3 months later replacing it. Feels a lot better knowing it's not going to die while in traffic. I've heard mixed reviews on cleaning the sensor and also heard not to clean them with Q-tips, so i didn't try it that way, now i wish i would have just to see. Link to comment Share on other sites More sharing options...
Precise1 Posted May 9, 2014 Share Posted May 9, 2014 Yes, you might have been able to just replace the housing, clean the sensor, install it and have it work fine. I understand the attempt to better the performance by cleaning the mas. Working for Nissan for 31 years and I have never cleaned a mas. I have seen the adverse affects of those who try. I have seen kn filters with too much oil kill a mas. On 90-96 300z's I have seen kn filters with the seam in the wrong position affect the mas. I will stay on the manufactures side and quote a non serviceable part Absolutely, this is a proven issue! Not to argue, but if you are going to buy/install a replacement, why not try cleaning it first? What is there to lose? This is obviously on one's personal vehicle, not in a shop scenario; customers don't want to hear 'maybe it will work' and have to come back... B Link to comment Share on other sites More sharing options...
fixinto Posted May 22, 2014 Share Posted May 22, 2014 ya i have cleaned mine with a q tip and alcohol and improved the idle and response greatly. Some people dont let it cool off proper before they try to clean it. That could damage the wire, other than that, I have never had an issue cleaning a MAF. Pat 1 Link to comment Share on other sites More sharing options...
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