Recently the car will just randomly not accelerate. This happened for the first time when I was heading to Philly last week. I was on the highway and floored it in 6th doing about 80 and it didn't accelerate. I threw it into 4th and stepped on it and the rpms didn't move and than all of a sudden the car took of. It didn't go anywhere for about a second, it wasn't the normal throttle lag.

It has done this the past couple days especially in the lower rpms. The intake sounds lke it does at WOT but the car slowly accelerates. I did the 2k1 maf swap about a month ago and didn't have one problem. The odd thing is if I turn the car off and restart it, the car doesn't do it. I'm wondering if it is a problem with my VAFC, MAF or maybe the infamous coil packs going bad.

Anyone seen this before? Anything to check or any suggestions? Thanks.

 

I don't know about thinking coil packs... you would certainly know if the engine wasn't firing on all cylinders. When you did the MAF swap, did you solder the IAT sensor to the clips?

 

I swapped it over but I didn't solder it. I just clipped them back in the way it was on the old maf. I did use a little bit of glue to keep the back end of the thermistor in because it didn't have the clip for the "u" shaped part of the thermistor.

 

Whether or not your IAT sensor is at issue, it's probably a good idea to solder the wire at the clips. And if that's not the problem, then at least you'll have some peace of mind.

 

I have this problem as well if the car is warmish. Apparently its a solenoid somewhere? Let me know how this goes for you.

 

Yeah replace the solenoid. Alien attacks can also break the solenoid.

 

lmfao. Dumb question, do 6 speeds have a torque converter? Wait yeah they do...

Viperss, I think you have the same problem as me, its the torque converter solenoid. Get it checked out and see if its working right. Im not sure the exact mechanical function but I believe the problem is that ours arent unlocking properly, so the car goes into a limp mode at/around 80-90 mph.

 

Unhook your VAFC and run stock MAF correction and report back.

 

It has never done that to me before. And it happens below that speed anyway. And after I downshifted, it went well past 80. I'm not sure it's that.

If I unhook my VAFC, the car doesn't run really. Like it feels like a bad maf - doesn't rev about 2500 rpm and misfires.

I read the codes and here is what I have and what I think caused them...

p0031 - because of headers
p0132 - because of headers
p0138 - because of headers
p0300 - no idea but I do get the flashing SES sometimes when accelerating
p0011 - maybe what caused the p0300? might this be my CPS failing?

I really do need some help guys, I hope you can help. Other things to note... rough idle (heavy vibrations) at 1k when car is cold. After warm up, it goes away. No trouble ever starting the car. I smell burning oil semi-often (just figured it was the motor burning oil like it's famous for) and normally when I restart the car, everything is fine. Sometimes the symptoms come back and I restart again and it's fine.

EDIT: Oh yeah, I still need to find a breather filter for the hose that was on the intake box. I have done a WAI and I don't know if that vacuum line not being attached to anything or having a filter on it would cause any of these symptoms.

 

Read this thread...

I was planning on getting o2 sims because of the headers, but wouldn't I continue to have these problems if in fact it's the o2 sensors? Or could I replace the o2's and then do the o2 sims? Does the o2 sims just tell the ECU not to throw an SES or what?

I am thinking that all the codes are from bad o2s and the vacuum line on the airbox not having a breather on it. I hope that's all it is.

 

P0300 looks like it's a random/multiple cylinder misfire.

http://forums.maxima.org/5th-generat...ite-smoke.html

According to Post #6 in the above thread it looks like at least one of your coilpacks is blown. Blinking SES = misfire detected.

 

But the thing is that it isn't all the time. And after it warms up, its ok and if it starts acting up I can just restart it and the problem goes away. I think it's the o2 sensors that are reading weird because they're bad and restarting the car makes the ECU have to read the o2 sensors as if the car just started so it runs better because it has no bad data to base it on. Does that make sense?

 

Tested it more today. Got out of work, turned the ignition on and waited for the VAFC to power up. Turned on the car and let it idle for about 3 mins. After 3 mins, it started to idle rough at the same RPM it was idling at. Got out of the car and listened to the exhaust and it sounded like a cammed v8. Got in the car, flashing SES. Revved it up, it was fine until the RPMs dropped back down and it started to idle hard again.

I left work and the car drove fine. I did a WOT merge on the highway, it was fine. Got off the highway and got to a 2 lanes to 1 merge and stepped on it and the intake noise was there but it just wasn't moving like it should. Turned the car off (while rolling), turned on the ignition, waited for the VAFC to boot, started the car and let it idle for a few seconds and continued to drive. Did the same WOT in 4th gear that I did in the lane merge down and the car moved like it should.

This is just really irritating sometimes. Any more input?

 

Probably coilpacks

 

Really? They could randomly do that? I figured if some were bad, it would run like **** all the time.

 

Car is still doing this. Reset the ECU and it ran better. I really don't know if the 2k1 MAF swap I did is the problem because I used a little glue on the thermistor. This is getting so annoying...

 

You figured wrong, they're capable of all kind of patterns. Please disconnect them one at a time when car idles rough to identify which cylinder is at fault. Then swap the coil with another working cylinder and observe if the problem moves with the coil. If it does - you have it if not - it's much more interesting. It might take few tryies as the coil might start working after swapping. Don't be fooled by this, wait a few days at least - it will come back if it was the coil.