Mass Air Flow Sensor or Not

[mrgrandpa1952]

Hi,
I have a 1992 Toyota Camry, 4 cylinder, 2.2L
Do I have a Mass Air Flow Sensor on this car? If not then what is in it's place. Problem I have is when I first start the car up in the morning and after I'm driving for a few minutes, as I'm coming to a stop the car starts to shake and the rpm's drop below 1000. When I stop I put in in neutral give it some steady gas and then it stops. It does not happen again. I thought it might be Mass Air Flow Sensor but I don't think I have that part. What can it be?

[dc_98_cam]

The Gen 3 wiring diagram ... actually looking at '94 version ... does not show a MAF for this car. There is an intake temperature sensor. The location diagram looks like it is in the air filter case ... maybe underneath the filter someplace, but can't tell too much from the service manual diagram.
You could check to make sure that there is no dust or debris interfering with air flow around it. I would guess that the service manual has some sort of diagnostic data ... It looks like a thermal resistor of some sort, maybe just a piece of platinum wire.

If it looks like a piece of wire is the active element, maybe you can wipe it off with a cotton swab ... see if it has any contaminants on it.
You would have to be careful if you touch the wire with anything, if you stretch the wire, it would be ruined.

[hill8570]

Originally Posted by mrgrandpa1952

Hi,
I have a 1992 Toyota Camry, 4 cylinder, 2.2L
Do I have a Mass Air Flow Sensor on this car? If not then what is in it's place. Problem I have is when I first start the car up in the morning and after I'm driving for a few minutes, as I'm coming to a stop the car starts to shake and the rpm's drop below 1000. When I stop I put in in neutral give it some steady gas and then it stops. It does not happen again. I thought it might be Mass Air Flow Sensor but I don't think I have that part. What can it be?

You've got a MAP (Manifold Absolute Pressure) sensor. Real unlikely that part is a problem -- they're nearly bulletproof.

When's the last time (if ever) you cleaned your throttle body and idle air control valve? The IAC has a history of getting gummed up from blow-by after a while, and can give you some really funky idling behavior, especially when temps are low-ish and the buildup is sticky.

The section on Throttle Body / IAC cleaning in Camry FAQ ------> READ FIRST -----> Comprehensive List of Gen 3/4 INFO and DIY has a good DIY writeup on cleaning the IAC (actually multiple DIYs -- I'd recommend the one that cleans the IAC on the car -- not as thorough, but the two screws holding the IAC onto the TB are easy to strip).

[dc_98_cam]

There have been quite a few posts and comments about the significance of the IAC valve. If you haven't had yours cleaned for a while, it could be worth the effort.

I think that you ought to take a quick look at the inlet air temp sensor, just to see that there is unrestricted air flow over that part. Its purpose seems to correspond to your original problem description.

The one other piece of the equation here is the oxygen sensor. The O2 sensors work in conjunction with the air inlet sensors to regulate the air/fuel mixture. If nothing else fixes the problem, you might consider trying a new 02 sensor ... there may be more than one of those ... have to check on that.

[LostSouthernStar]

In addition to the above suggestions, use an OBDI code reader to try to see what is causing this problem.

Second suggestions is have a professional mechanic investigate your vehicle if you cannot attain an OBDI reader.





Hope this helps! God Bless!


-LSS

[hill8570]

Originally Posted by LostSouthernStar

In addition to the above suggestions, use an OBDI code reader to try to see what is causing this problem.

Second suggestions is have a professional mechanic investigate your vehicle if you cannot attain an OBDI reader.

Reading the codes on a '92 involves jumpering a couple of contacts with a paper clip and watching the check-engine light blink out the code. But if the CEL ain't on, there ain't a code to read nohow.

[Mike Gerber]

I have to agree with hill8570. Clean the throttle body and idle air control valve first. Here is a direct link to the thread he recommended:

How to: Cleaning Throttle Body -4 Cylinder Engines- With Pictures

Mike