garends

Hello,

Problem Description

Hesitation during full acceleration. Noticeably worse when the engine is cold and under 3,000 rpms. I can gradually get the RPMs to increase by gradually applying moderate throttle. The Maxima is drivable as long as it is warmed up and you are not accelerating too quickly.

When I put the throttle to the floor. The engine sounds like more air is going into the engine, but ZERO acceleration, and RPMs do not go up.

Background - Might be useful

I recently took a road trip to Texas from Colorado, this is when the problem started. The day before I left I cleaned out my K&N filter, and oiled it. I noticed the problem the first day of the road trip and is not changing (getting worse or better)

While on the trip it threw the following codes: P0505 Idle Control System, P0130 O2 Sensor, and P0705 Transmission Range Sensor (Car is a manual)

I changed the O2 sensor, and reset the CEL. Has not come back yet after 1 week (Only drove it a 3-4 times since)

I also cleaned out the MAF with the CRC MAF spray and added some Chevron Techron with some new gas.

Current Plan - Please Critique!

1. Check spark plugs/ignition coils
2. Rent a fuel pressure kit and test fuel filter/pump
3. Try a used MAF at junk yard
4. Check TPS, IACV

Any advice will help me greatly. Thanks in advance. Graham

JvG

I also use the k&n filter.

You used too much oil on the filter.
You were supposed to do less.

The excess oil is coating the maf sensor.

Buy some CRC Maf cleaner. Spray it on the maf sensor wire.

​​​​​​See if this improves the situation. You might want to clean the filter again. Don't spray so much oil on it in the future.


​​​​

garends

Thank you, I will try that first.

Turbobink

iTrader: (2)

Sorry, here's that broken record again ... Sorry.

Not to redirect from any advice already given, but it's my personal advice that attention be given to the following:

MAF;
TPS;
IAT (intake air temperature sensor).

Based on your having linked your symptom to the car's operating temperature, I'd also investigate the ECT sensor.

Zerodrag

iTrader: (1)

"The engine sounds like more air is going into the engine, but ZERO acceleration, and RPMs do not go up. "


Please elaborate more on this. Is it noticeably misfiring, or just falling flat on it's face?

garends

Thanks for asking, sorry it's hard to describe. I will try to take a short video later today.

It is falling flat on it's face at lower speeds and rpms. Feels like all power to the engine is gone at that level of throttle. Engine feels okay when it falls flat, no noticeable backfiring or shuddering. No audible misfire.

Additionally, at higher rpm and velocity (40mph and up) it turns into a 1-2 hesitation instead of falling flat.

Hope this helps describe it. Thanks again for everyone's advice.

Update

Cleaned the MAF with CRC cleaner yesterday for the second time. Unfortunately, the problem is still there. Going to look at replacing the MAF or testing the TPS next.

JvG

People who over oil the k&n filters end up with oil on the maf sensor wires. Which makes the cause (seem) like the maf. So I agree with your reasoning. But the real true cause is the filter. Some maf spray, a new filter, (or a cleaned and properly oiled k&n filter, will fix this in less time than it takes to have a cup of coffee.

JvG

Did you clean the k&n like I asked you to? If not, you will have the same issue with this maf, or a brand new maf.

This is a common issue with re oiled k&n filters.
Regardless of vehicle make or model.

garends

Sorry I did not, I was being lazy. I will go back and clean the K&N.

Thank you so much for your help.

The Wizard

iTrader: (43)

Either you killed your MAF by over oiling the K&N filter, or coincidentally your coilpacks are failing.

Wolcottmax1

Hopefully you changed your MAF as that is probably the issue. Good luck

garends

After replacing my air filter and cleaning my MAF several times, there was no difference. I replaced my MAF with a new one which fixed the problem completely. What a relief!

Thanks for everyone's help.

Graham

The Wizard

iTrader: (43)

Thanks for coming back and wrapping up your car trouble story; will help others in the future. Glad she's back on the road.

garends

The problem came back. It seemed to have gone away after changing the MAF, but it is now back today.

Below is a video. CEL is P0505 which I think is unrelated


Next steps (Please correct me if you would do something different.

1. Check inside intake airbox for K&N oil residue (Even though I changed the filter to a normal one, I thought maybe some oil got in the box)
2. Check the voltage at the MAF sensor
3. Check Ignition Coils
4. Check TPS
5. Fuel Pump?

komik

When mine starting hesitating over 2k rpms it was a coil pack. It didn't throw a code. I had a full set of spares from an old parts car, so I swapped all six and it solved the problem. I know there's info somewhere about testing them with a multimeter. Or you could unplug one at a time and run the engine. If 5 of 6 make it worse and 1 has no change you've found the culprit.

garends

Tested the resistance of all the coil packs, and all of them tested good.

Next, I changed out the spark plugs, figuring that couldn't hurt, and I found that there was oil in one of the wells.

It looked pretty bad, not just a residue, but a significant amount of oil.

The car has recently started to stall, misfire/backfire (one "pop" while idle gets low), and also has a hard start after sitting for ahile. Could this be the cause of my issues (power loss/hesitation, hard starting, rough idle)?

Planning on replacing the rear valve cover gasket and oil well gaskets ASAP. Anyone know of a good gasket kit?

Thanks again

JvG

The valve cover leak might cause a mis fire in the cylinder.

the hessitation and starting difficulty could be caused by low fuel pressure. Like from a bad fuel pressure regulator, or from leaking fuel injectors. Seems like most of our cars have bad injectors eventually.

please remove the vaccuum hose from the fuel pressure regulator. If the hose smell like gas, the fpr is bad.

did one or more of your spark plugs smell strongy of gasoline?

You might have a partially blocked cat. That would explain lack of power at higher engine revs.