96 Camry LE V6 problems when warmed up

[showsol94]

Hello, my father and I have been having a real problem with my 96 LE V6. It has 190k on it and there has been a problem when the car warms up.

The car runs absolutly perfect when it is cold. But once it warms up, it seems like something gets to hot or a sensor is bad so it restricts the motor to only rev up to 2,500 rpm. We have checked all sensors and believe all the grounds are correct. Could this have something to do with the coil packs? Or any other ideas?

Because it governs at this low rpm, the car only goes up to about 60 miles per hour. Its really weird because other than the governing/cutting out, the car runs perfect!

We are so confused and really need help!

[projektvertx]

Is the car throwing any codes??

Has the throttle body ever been cleaned in it's lifetime? Maybe the throttle plate movement is restricted?

[showsol94]

I dont think it would be the throttle body because it revs just fine before it turns warm. Isnt there a cold start phase in the camry where it delivers more fuel at first then cuts back when warm? Could it be injectors?

Code thrown was the cam position sensor

[projektvertx]

Cam position sensor has a direct link to proper fuel injector operation. A bad cam sensor could cause injectors to operate slightly off (but not the other way around). I would start by testing that sensor. You could also pull out the front 3 injectors and take a look at them.

[Jason.MZW20]

Originally Posted by showsol94

Code thrown was the cam position sensor

That puts the ECU in extreme limp mode because it's an integral part of the ignition and fuel injection system. If the ECU couldn't compensate, it'd stop all ignition and injection.

FYI, the resistance of the sensor changes from cold to hot, so it's possible it's in spec when cold, and out of spec when hot.

[showsol94]

How would I test this sensor? We let the car warm up to where it messes up, shut it off, tookthe sensor off, cooled off the sensor, then put it back on the car and started it really fast to see if it worked for a second while it was still cooled down. but it didnt fix it

Any pointers on how to check?

[projektvertx]

Originally Posted by Jason.MZW20

That puts the ECU in extreme limp mode because it's an integral part of the ignition and fuel injection system. If the ECU couldn't compensate, it'd stop all ignition and injection.

I thought cam sensor just determines injector firing order no?

FYI, the resistance of the sensor changes from cold to hot, so it's possible it's in spec when cold, and out of spec when hot.

Interesting, I didn't know it had 2 modes, althought it does make sense...

[Jason.MZW20]

Originally Posted by projektvertx

I thought cam sensor just determines injector firing order no?

Mainly it does, but the ECU needs the signal because the 1MZ uses electric/direct ignition. At least the crankshaft position sensor is there as a backup. When the sensor fails, the ECU moves to asynchronous injection (worse than batch fire), so all injectors fire to ensure the engine can still run.

Usually the distributor houses the cam position sensor.

[showsol94]

how can i test this?

[Jason.MZW20]

Originally Posted by showsol94

How would I test this sensor? We let the car warm up to where it messes up, shut it off, tookthe sensor off, cooled off the sensor, then put it back on the car and started it really fast to see if it worked for a second while it was still cooled down. but it didnt fix it

Any pointers on how to check?

Measure the resistance (Ohms) of the sensor's terminals with a multimeter. I'll give you the values.

Denso made cam position sensor:

Cold - 835-1400 ohm
Hot - 1,060-1645 ohm

Wabash made cam position sensor:

Cold - 1,690-2,560 ohm
Hot - 2,145-3,010 ohm

The ECU is calibrated to accept both since they use different functional values.

[projektvertx]

Originally Posted by Jason.MZW20

Mainly it does, but the ECU needs the signal because the 1MZ uses electric/direct ignition. At least the crankshaft position sensor is there as a backup. When the sensor fails, the ECU moves to asynchronous injection (worse than batch fire), so all injectors fire to ensure the engine can still run.

Usually the distributor houses the cam position sensor.

I ought to sit down with you and 73sport one day so you can dispense yor full wisdom to me

So one more (maybe noob) question: Wouldn't the engine run better in this scenario if it relied on the crank sensor instead of going into asynchronous injection? I mean, crank sensor measures with cylinder 1 is at TDC no? Or have I forgotten my basic principles here

[showsol94]

which does a stock camry have? denso or wabash?

[abew330]

^^^^^^^^ take it off to find the P/N

[showsol94]

I just took the sensor off and the only print is on the metal party and it says...

"TOYOTA
90929-05013
029600-0262
12027"

Also, sorry to sound annoying, but how do you test the ohms?

[73sport]

With an Ohms eater. . . j/k

Commonly refered to has a hand held volt meter, DMM (digital multimeter). They measure DC volts, AC volts (RMS), Diode break down voltage, Current nad sometimes even temperature.

The meter has test leads and you set it ohms, verify your test leads when open read infinite ohms and when the leads touch read Zero ohms or at least less than 2 - 3 ohms. Subtract the the shorted # number from your actual test and/or use the Zero function if the meter has it. Also, your body and other materials are conductive so YOU as living being can effect the measurement by touching the leads with your fingers.

Buy one, learn how to use and you'll find all kinds of uses for it.

http://www.google.com/search?hl=en&s...AAAKoEBU_QxidJ