1992 Nissan Maxima mass air sensor?

ROB.BOB.DAVE

MEMBER
1992 NISSAN MAXIMA

Engine Performance problem
1992 Nissan Maxima 6 cyl Front Wheel Drive Manual

If I push my vehicle a bit harder (130 kph) It runs a bit warmer. This seems to cause a problem with the ECCS or ECU as it limits the fuel. When this occurs, it does not make any difference if you touch the throttle or put it to the floor, there is almost no acceleration. This seems to be causing a lean mixture situation where the engine temp continues to rise. Dropping the speed to 120 or less and allowing the operating temp to drop seems to correct the problem and power returns. The O2 sensor and the cat have both been replaced. Could this be a MAF (mass air flow) sensor failure?

3 Replies

KHLOW2008

MECHANIC
41,815 POSTS

Hi rob. Bob. Dave,

Problem should be with the overheating. Seems the cooling efficiency is insufficient and the most likely cause is a partially clogged radiator. Getting this rectified should solve the problem.

When the ECT signals to the PCM that overheating is occurring, it would try to protect the engine by reducing the power. When temperature rises to the extreme, the engine would cut off.

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Friday, September 3rd, 2010 AT 7:46 AM

ROB.BOB.DAVE

MEMBER
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While waiting for your reply, I did much research elsewhere on the internet and found the following;
The MAF is a platinum wire that indicates air flow by heat and resistance. If the MAF is "dirty" it may not operate correctly. It may not be cooled by the intake air flow correctly and then cause an incorrect value to be passes to the ECU (engine control unit) or ECCS (engine concentrated control system) (the computer) which may cause the ECU to incorrectly limit the fuel to the engine. This would cause the engine to run lean which would cause the engine to run at a higher temperature. It was recommended to spray the MAF with carburator cleaner only, not touching the internal wire physically. This I did and after an extended drive, the results are; no loss of power and the engine maintains a steady temperature. This being said, there was one other factor that could not be duplicated, the outside air temp. The problem occured on a day when the temp was 30 celcius (85 F). The temp was 20 celcius (70 F) for the after cleaning run. Both times the air conditioner was on to try to duplicate load and conditions.

I would like to state, I never indicated the enging was "overheating". I only stated it was running warmer than usual. The fluids in my radiator are clear with no particulate matter contamination.

Your solution seems to be in error.

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Sunday, September 12th, 2010 AT 7:36 AM

KHLOW2008

MECHANIC
41,815 POSTS

Thanks for the input and sorry if I misunderstood your problem.

You mentioned it ran warmer than normal and I misrepresented it as overheating. I did not really meant that the engine is overheating but rather the increase in coolant temperature can register in the signals to the ECU.

Without the physical vehicle we can only rely on the information provided and any misinterpretation can mean a difference in the answer.

A dirty MAF can cause the problems mentioned but it can be under any operating conditions but more noticeable after warming up to operating temperature because that is when the cold start mechanism is turned off and metering of fuel is more precise with no compensation for cold start.

Glad to know you have fixed your problem.

Have a nice day.

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Monday, September 13th, 2010 AT 8:32 AM