Throttle Issue

[bmconway76110]

2001 QX4 4WD. No codes. 133K. Runs perfect when the engine is cold. After it is up to temp, there is a spot in the throttle at about 1500 RPMs where the RPMS will fluctuate, almost rhythmically. If I go a little deeper into the throttle, everything is fine.

I can avoid the area of the throttle that causes the issue for the most part, but it will show up when creeping a parking lot or stop and go traffic.

Tried cleaning cleaning the MAF to no avail.

Anyone have any ideas?

[Slowride92]

Mine started doing the same thing a couple days ago, along with an intermittent (possible) transmission issue. Following this post closely.

[ArmedAviator]

With the engine at 1500 RPM and you're getting this fluctuation, ho much fluctuation do you see? +/-300 RPM?

Is the vehicle in gear when this occurs? Moving or stationary?

[bmconway76110]

It will float repetitively and rhythmically about 300-400 RPMS

If you think it's a trans issue, don't. That what I thought at first. It's probably just the truck bucking due to the fluculation in the RPMS

It happens in gear or park. It is most certainly an issue with air fuel delivery and or management.

Now, with all of that said, I did throw a P1130 swirl control valve code this morning.

I need to check the vacuum lines to make sure my friend and I didn't forget something when we were cleaning the MAF and the throttle body. I cleared the code to see if it returns.

I don't know anything about the swirl control valve, so I am relying on you guys. Could that cause my symptom?

[ArmedAviator]

I'd start with suspecting the swirl control valve since you got a code. I have no idea what that is, either. After that, vacuum leak, as you already deduced. Check the MAF connection and make sure it's not installed backwards (it can happen on some vehicles, not sure about yours). Also consider a "dead zone" on the Throttle Position Sensor.

[bmconway76110]

My summer car is going to the dealer for winter storage perp tomorrow so I won't drive the QX4 until Tuesday. I am going to keep my eye out to see if the code returns this week. But I tend to agree if the OBD is throwing the p1130 the swirl valve may be my culprit.

[bmconway76110]

Got the code again at lunch today.

If the weather is nice this weekend I will pull the engine cover and check all of the vacuum lines

[bmconway76110]

New plan guys... The service engine soon light is driving me bat sh!+ crazy. So, in a few weeks I am going to a SCV and MAF, replace both of those and see what happens.

Does anybody know the part numbers?

[barnaclebob]

There are several threads on the MAF sensor, use the maxima part number for a $300 savings. Google some combinations of nissan pathfinder MAF or Mass Air Flow and Maxima and you should find forum posts here on it.

[bmconway76110]

The MAF isn't causing me an issue. I found one with the housing for 46.00. I can't find the Swirl Control Solendoid Valve part number.

[bmconway76110]

I ordered up the MAF from 1AAUTO.COM for 45.00

No one, including my Infititi dealer can come up with the part number for the Swirl Control Solenoid Valve. Errrrrr.....

[bmconway76110]

The good news is I replaced the MAF. The truck is running better but the problem with the throttle is still there. The better news is I found the vacuum hose to the swirl control valve was disconnect so that was probably causing the p1130.