P1110. Car misfires @ idle intermitently... plugs??

[CanuckQx4]

I got this car as a hand me down, its a 01 qx4. It recently started hiccuping at stoplights, when its cold like when I go to work in the morning when its idling it will PURR like a kitten, but when warmed up and running for a while when I stop at a light it will feel like the engine misfires and sputters for a sec, runs fine for a few seconds, stutters again... sometimes more than others..

So I pulled the CEL today and I got a P1110.

That aparently is car specific so the obd2 sheet wasnt much help for me.

Can anyone help me on what I should go about doing??

Thanks

[asnorton44]

I have a 2001 QX4 that had the same exact problems. When cold, it would idle fine but as soon as it warmed up it would have rough idle and die when idling. I was throwing P0300 and P1320 and I replaced the coils and plugs which fixed those codes but car would still die when idle (no codes). It turned out to be my MAF. I replaced the MAF and the engine now runs great.

What led me to find out it was the MAF was I got the engine warmed up so it would die, when I disconnected the MAF it would idle fine just wouldn't rev (I believe this is a engine safety feature).

Try disconnecting the MAF with a warm engine and see how it idles. Thats how I singled out my problem. May work for you.

I replaced it with the 2000 Maxima MAF which gave me P0100 but the code cleared after about two weeks of driving. Probably the ECU re-learning the new MAF.

From what I understand from reading multiple threads the 01s do have a problem with coils/plugs/MAF.

I would replace the plugs and clean the MAF, if that does not fix it, it is probably your MAF as the coils should throw a code.

[Pwnin O'Brien]

2001's are notorious for having issues with the P1110 (IVT). Most have remedied the issue by using a higher-weight oil to increase oil pressure. Do you know what weight you are currently using? As for the sputtering and whatnot, use asnortons recommendation and check the MAF.

[asnorton44]

I had code P1140, which I believe is the same as P1110, or very closely related, correct me if I am wrong.

I replaced with part 23731-2Y52A which fixed the problem.

[Chuck Tribolet]

P1110 will NOT cause a misfire.

And replacing the sensor is NOT the only fix for the code. I've been dealing with this
code (and its sister P1135 (other side)) for several years. I see three general causes
for this:

- The cam advance is oil pressure activated. Your truck has lots of miles and the oil pressure
is going down. Solution: run a thicker oil, and don't floor it between 1500 and 2500 RPM,
That causes the cam advance to kick in, but the old engine low oil pressure can't advance'
it. More RPM, you have enough oil pressure.

- The sensor is bad.

- The actuator is bad

Dig around on this site. Nistech has a good thread in how to tell the difference, But most of
these are low oil pressure.

Chuck

[asnorton44]

You can also clear the code, and swap the sensors. If the code switches sides its the sensor. If it stays on its the solenoid.

[CanuckQx4]

Ya I did some researching o the night I made these posts and I found q thread by nistech that i can no longer find,but it said if you have a -10 code, then clear it while driving with a handheld, then put a heavy load on the motor by climbing a slight hill for 20 seconds straight with no thrtottle change, if the code came back on, it would be the solenoid

Does anyone know what solenoid they were taling about it and its part number possibly?? Im unaware of the location

Ill try the MAF test and see what happens.

Its weird tho, somedays it runs great, some it idles at lights horibly. Getting a litle old driving around with my obd2 scanner always plugged in

[Chuck Tribolet]

The solenoids are near the front of the heads, one on each side. An electrical signal allows oil pressure to advance the cam. However, if your P1110 is caused by low
oil pressure, replacing the solenoids will NOT fix hte problem. I've had both of mine replaced, and it didn't cure the problem.

P1140/P1145 are a sensor problems. P1110/P1135 could be low oil pression, bad solenoid, or bad sensor. I believe bad sensor is very unuusal.

I'd suggest getting an FSM.

[CanuckQx4]

I have an FSM. P1110 comes on every 20miles or so.

I havent checked my oil since last change 3k ago, higher weight would help that problem?? 10-40??

[mrpatel302]

I've had both of mine replaced, and it didn't cure the problem.

P1140/P1145 are a sensor problems. P1110/P1135 could be low oil pression, bad solenoid, or bad sensor. I believe bad sensor is very unuusal.

I'd suggest getting an FSM.

Hello Chuck.
new to the forum here. I have the p1135 and p1110 codes and i ve tried everything that i could, im thinking of just putting in new solenoids now. i ll go with one side and see if that solves the issue and then try the other bank.
Since you mentioned you replaced yours. would you hapen to have the product number and where else you could get this..besides the dealership(they are expensive).

[Chuck Tribolet]

I don't have the part number.

I've had these codes for several years, off and on. I can keep them a way most of the time by:

1. running 10W40 instead of 5W30.
2. Keeping the revs above 2500, esp. going up a hill. I have stick shift.

I don't have the part numbers, it was a long time ago.

The solenoids are very accessible and would be a DIY project if you have any experience.

[Densetsu]

I had the same idle problem, where when idle at a light after the engine was warm the RPMs would cycle from 500 to 600 and back down/up every second. Got some nice vibrations through the steering wheel and brake pedal, too. This only happened in gear, and was more pronounced in reverse than drive. Changing the transmission fluid caused the problem to disappear, but I have a feeling that this is more of a band-aid solution and didn't address the underlying problem.

Prior to that I cleaned the MAF, with little to no effect. If the problem comes back, I'll have to give the MAF test a try.

[ARKQX33V6]

Densetsu, changing the transmission fluid is good. The valves in the transmission #1 gear can get held up to a partial position because of debris floating in the ATF and this has been known to cause shift delays. While you are stopped, in gear the delay through say 3 to 2 to 1 then stop can load up the engine more or less as the transmission winds down. Dependent on your torque convertor.

A good reason to dump the ATF fluid is this effect that you describe. Also before changing the ATF did you notice sloppy up-shifts. It varies with the solenoids that get hung up.

The solenoids are electro, mechanical hydraulic, where the electro mechanical works but the hydraulic gets a bit hung up, thus the signals get mixed up and if long enough, the ratios will throw a MIL light warning.

I have discovered that changing the ATF in the transmission resolves this, so its every other year. Cheap insurance.

[Densetsu]

I didn't notice a consistent shifting problem. Every few weeks, usually when merging onto a highway, I'd get a slight but noticeable hesitation on shifting, usually from 3rd to OD. It's an '04 I bought last year and the last owner gave me records of everything done to it -- no sign of a transmission fluid drain/replace or flush in these records.

I should clarify my last post, there's still some vibration and a slight RPM drop when I'm idle in reverse, not nearly as bad as before but still there. Another drain/refill should probably be done since I only got half the ATF out in the last drain/refill, and since the fluid was a culprit in my idle problem I really should drop the pan and change the filter too.

I'm with you on that, changing transmission/diff/transfer case fluids on an annual basis is a great insurance policy. Any used vehicle I usually swap these out once the weather gets nice and warm out. ATF is cheap compared to a new transmission.

[Towncivilian]

The filter in the pan is nothing but a large mesh screen, it doesn't catch anything but giant particles that would surely kill your transmission. You may still want to drop the pan to examine the magnet and clean the metallic fuzz off of it, though. Dropping the pan will also get a bit more fluid out, while you're there change the filter anyway. An in-line transmission filter will be significantly more efficient and is easy to install.

[ARKQX33V6]

IAV, sounds plugged, thus air flow at idle when throttle plate is closed not enough air to bring idle around 700-750. I have just removed from car and soaked in a mild solvent, blown out and reinstalled...good to go. If it is bad you may hear it whine, growl as ignition switch is turned on.

With low oil pressure on motors with high mileage going to 10/40 sounds like it works but what about checking the relief valve for the oil pressure and simply changing out the spring. And what is considered high mileage?

Does anyone with this oil pressure problem know what PSIG the pump is displacing, being a gear-rotor lobed pump, the pump itself should be good but the relief valve spring may be weak.

[CanuckQx4]

The IAV?? You mean IACV on my vq35? Ive had that off before, it doesnt really have anything to clean or spray to it though. Ill take a pic I guess

Id love to be able to start it with the throttle closed and have it idle on its own, sumtimes drops to 450RPM with the A/C

[Chuck Tribolet]

The relief valve doesn't kick in until higher rpms when the oil pump is putting out more oil than the bearing clearances can consume. At low RPMs it's closed. Oil pressure gets low in high mileage engines because wear has opened up the clearances.

[CanuckQx4]

IACV????

[ARKQX33V6]

IACC, you are right it provides the idle air that is used when the throttle plate is fully closed , the valve by-passes air around this closed throttle. Be sure to clean your throttle from carbon deposits.

That IACV should be able to provide more or less air by virtue of its control to satisfy the ECU along with the coolant temperature sensor to establish 700-750 RPM at operating temperatur.

Along with this is vacuum and vacuum is created by the down stroke of cylinders, but that vacuum draws in a lot of air about 15x as much as fuel/air mixture so other things must be right.

You EGR, PCV, intake filter, brake booster to name a few use vacuum, if any of them are leaking within this closed system idle will suffer.

As an example when all is warmed and your idling aling at 450 RPM as gently as possible by hand try to open the throttle valve off of the closed position, does the engine speed up quickly or bog down.

You are doing the same as the IACV, is that air valve passing gas (air)?