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Discussion Starter · #1 ·
So I noticed that my Rav is struggling up hill. It accelerates quite slow as well on flat ground but when at highway speeds seems fine until I encounter an incline. Once on an incline, with the pedal to the floor, it won't go past 4000rpm. I also did the basic transmission tests, such as checking to make sure it shifts at correct rpm and down shifts and O/D works...

So far the things I have done/replaced (When I bought it in the spring):

-New Fuel filter
-Changed transmission fluid and cleaned suction screen
-Set throttle position sensor and throttle cable
-replaced EGR VSV
-replaced sparkplugs
-Changed engine oil and filter
-Changed diff and transfer oil
-New Vacuum lines
-Installed 3" Ram Air (the problem existed before this)


I noticed that if the car is nice and warm and I turn it off and try to start it right away, it will die unless I give it a tap on the gas. (maybe unrelated but wondering if it's a potential fuel delivery problem)

Any ideas?
 

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Try a fuel pump pressure check AND a fuel pump pressure leak down check.
 

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Discussion Starter · #3 ·
Try a fuel pump pressure check AND a fuel pump pressure leak down check.
Fuel pressure check:
-50psi with fuel pump on.
-50psi with engine at idle
-Leak check held at 46psi after 5min dropped to 45 psi at 6min and 44psi after 7min...

Seems to check ok. I'm going to do "Throttle body - On vehicle inspection."
 

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I'm having the same exact problem with mine that I just got. I think it's the CAT, but not sure. Keep us posted on your results, and I'll do the same!
 

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Muscle Hamster, Where did you hook up the fuel pressure gauge, to do your test? These cars have no schrader valve, so I don't know where to attach the pressure gauge? I would like to test mine, and see what kind of readings I get. I will post them here, so we can compare are results.

Also have you checked the color of your plugs? This will tell you if it's running Lean or Rich!
 

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Discussion Starter · #7 ·
So I cleaned the throttle, no luck but it did solve the problem of my rav not starting properly after shutting it off. (cleaned IAC valve). So I think I have an exhaust leak but I dont have the time or money at the moment to venture into that can of worms. Any one know where I can get a better exhaust manifold? does the one from the "perfomance" version of the engine fit?

Other than the exhaust leak it might be a problem with the transmission...
 

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Discussion Starter · #8 ·
Muscle Hamster, Where did you hook up the fuel pressure gauge, to do your test? These cars have no schrader valve, so I don't know where to attach the pressure gauge? I would like to test mine, and see what kind of readings I get. I will post them here, so we can compare are results.


Also have you checked the color of your plugs? This will tell you if it's running Lean or Rich!

If you look behind your air box, under the relay box, there is a fuel filter. Rent a fuel pressure test kit from your local auto parts store, remove the banjo bolt from the top of the filter (off-set open ended wrenchs help in this) and use the m12×1.25 extended banjo fitting from the kit and plug into the fuel filter. You may need new copper gaskets (i re-used mine).

My plugs were slightly on the hot side but I'm not to worried. I could use a new wire and cap set though ?
 

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'99 RAV4.1, 3MZ-FE, E250F 4x4, Torsen Dif
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Possibilities:

Throttle Position Sensor. Measure the output voltage and make sure it ramps along with your throttle position between 4v min at idle and 5v max at wide open throttle volts. A faulty TPS could definitely cause this. without TPS correlation the ECU will compensate for slow changes, but that fast change it seems almost unrecoverable. The transfer from idle vacuum to 0 vacuum so quickly with faulty TPS input will confuse the computer more quickly than it can accommodate for.

https://youtu.be/cPkk6md3Sy0

The Manifold Absolute Pressure (MAP) sensor is used by the Powertrain Control Module (PCM) or on out engines the ECU for engine load input. The PCM uses this input, as well as others, to calculate the correct amount of fuel to inject into the cylinders.

The MAP sensor measures the absolute pressure inside the intake manifold of the engine. At sea level, atmospheric pressure is about 14.7 psi (pounds per square inch). When the engine is off, the absolute pressure inside the intake equals atmospheric pressure, so the MAP will indicate about 14.7 psi. At a perfect vacuum, the MAP sensor will read 0 psi. When the engine is running, the downward motion of the pistons create a vacuum inside the intake manifold (For the purposes of engine control, when a technician says vacuum, what they are really saying is pressure that is less than atmospheric pressure). With a running engine, intake manifold vacuum usually runs around 18 - 20 “Hg (inches of mercury). At 20 “Hg, the MAP sensor will indicate about 5 psi. This is because the MAP sensor measures “absolute” pressure, based on a perfect vacuum, rather than atmospheric pressure.

1. Excessive fuel consumption

A MAP sensor that measures high intake manifold pressure indicates high engine load to the PCM. This results in an increase of fuel being injected into the engine. This, in turn, decreases your overall fuel economy. It also increases the amount of hydrocarbon and carbon monoxide emissions from your vehicle to the surrounding atmosphere. Hydrocarbons and carbon monoxide are some of the chemical components of smog.

2. Lack of power

A MAP sensor that measures low intake manifold pressure indicates low engine load to the PCM. The PCM responds by reducing the amount of fuel being injected into the engine. While you may notice an increase in fuel economy, you will also notice that your engine isn’t as powerful as it was before. By reducing the fuel into the engine, combustion chamber temperatures are increased. This increases the amount of NOx (oxides of nitrogen) production within the engine. NOx is also a chemical component of smog.

Cam Position Sensor:

1. Vehicle does not drive like it used to. If your vehicle idles roughly, stalls frequently, has a drop in engine power, stumbles frequently, has reduced gas mileage, or accelerates slowly, these are all signs your camshaft position sensor could be failing. If you have any of these symptoms, it could mean the camshaft position sensor needs to be replaced by a professional mechanic as soon as possible. It needs to be completed before the engine cuts out and dies while you are driving, or does not start at all.

2. Check Engine Light comes on. The Check Engine Light will come on once the camshaft position sensor starts to go bad. Since this light can come on for many different reasons, it is best to have the vehicle thoroughly inspected by a professional. The mechanic will scan the ECM and see what error codes are being shown to diagnose the problem quickly. If you ignore the Check Engine Light, it can lead to serious engine problems, such as the engine failing.

3. Vehicle will not start. If the other problems are ignored, eventually the vehicle will not start. As the camshaft position sensor weakens, the signal it transmits to the vehicle’s ECM also weakens. Eventually, the signal will weaken so much the signal will switch off, and so will the engine. This can happen while the vehicle is parked, or while you are driving. The latter can be a dangerous situation.

As soon as you notice your vehicle does not drive like it used to, the Check Engine Light is on, or the vehicle will not start properly, the sensor may need to be replaced. This problem should not be ignored because eventually the engine will stop working entirely.

https://youtu.be/hvaFBlFzFD0

Spark plugs, coil, spark plug wiring.

There are other issues but many you have already addressed. If any of this helps let me know.
 

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Discussion Starter · #11 ·
No, I don't think it's an engine performance issue, if it is, it has to do with the exhaust system because everything else checks out. There is a strange whistle coming from the rail pipe if i rev it up to around 5500-6000 rpm.

I also tried shifting manually and it seems to perform better but when in "D" I noticed it doesn't give me power when I demand it. If I put the pedal to the floor it will shift at 4000rpm'ish for each gear and will not go higher than that. Seems like it kicks into overdrive intermittently as well. (i did check all the cable rigging and it's in limits)...
 

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Discussion Starter · #12 ·
Bazinga!

So when I bought the rav I rigged the throttle according to the maintenance manual. Now I got talking with my boss at work and he suggested the kick-down cable... After discussion we came to a conclusion that because the cable is old, it probably stretched, so the dimensions called out for in the toyota manual are now out the window.

So I tightened the cable (the one connected to the upper part of the cable cam assembly). I just made sure there was no slack and it wasn't pulling on the cable cam.

Before you test drive make sure the engine (and transmission) are warm. because it's old and only shifts correctly when warm.

The acceleration issues are corrected and the rav goes into overdrive whem power is needed.

I still need to do another fluid change and install an aftermarket cooler for the transmission (A540H). This should take care of some of the minor issues that are plauging my rav.

Hope this helps...
 

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Thanks for the update! But I'm not sure what you mean by cable cam assembly?? Where's that located? Pics would be great if you have some. Also what maintenance manual are you using??
 

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So basically, you just tighten the throttle cable? What do I need to do to tighten it?

Its hard to believe that just tightening the throttle cable gave you more power up hills???
 

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Discussion Starter · #16 ·
So basically, you just tighten the throttle cable? What do I need to do to tighten it?

Its hard to believe that just tightening the throttle cable gave you more power up hills???
That's what I thought! But they call it the throttle cable in the manual but if you follow the cable from the throttle it's the one that comes out of the black box by the drivers side fender. The other cable (the one that you can adjust with the two nuts on it) is actually your kickdown cable. So what's happening (roughly) is when you put your foot to the floor your car is shifting through gears as it would if you are cruising down the road because O/D is not engaging giving you a lower gear as demanded by your foot. It just stays in a high gear.

I might be speaking out of my ass because I haven't done all the research to back up what I've said... been to busy lately.
 

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So, which cable do I need to adjust? The throttle cable, coming from the black box, or the kick down cable?

If it's the throttle cable, where do I just it at? Near the throttle, or at the black box??

Should there be any slack, or just tighten it until it's taught??
 

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So, which cable do I need to adjust? The throttle cable, coming from the black box, or the kick down cable?

If it's the throttle cable, where do I just it at? Near the throttle, or at the black box??

Should there be any slack, or just tighten it until it's taught??
As far as I know all cables should be taught, without pulling.

I had a similar issue, but I guess it was not the same. I can downshift out of od just fine.
My issue was I had no power pulling hills, even small ones. I would have to floor it in order to downshift and keep speed. If I was even able to keep speed. The way I fixed after a few years, a few dollars, and quite frankly... giving up on it all together, was cleaning my grounds and replacing the main fuses (3 of them) on the positive cable (where it bolts onto the battery). I know it sounds weird, but it worked. I did all of the things he did, and lots more. This also included removing the alternator and wire brushing the parts that touch the engine so it grounds well and can produce more voltage.
I have a post on the front page '7mpg plus with oil change and premium fuel'. Go to last page and read what all I did if your issue is the same as mine. It still isn't perfect, but it is darn close.
 

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Thanks Needa for the post! It sounds like I have a similar problem. Just so I'm clear, are you saying, that by cleaning the grounds and changing the fuses, you improved your spark, which in turn improved your power?? My spark plugs are white as a ghost, which means they are running lean, which leads me to believe that they are getting plenty of spark. Am I looking at this the wrong way? The car ideals fine and runs good over all, but it really sucks when I hit the slightest hill and it loses power just like yours did. I plan on doing what you said you did, it can't hurt. What all grounds did you clean, and what do you think really made the difference, the grounds or the fuses?

Also, Did you clean the throttler body or the Idle Air Control (IAC) or change the TPS or MAP sensor? If so did any of that help?

BTW. I read your other post, 7mpg plus. but it left me a little confused with all the things you did, It wasn't clear about what helped and what didn't help!
 

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Thanks Needa for the post! It sounds like I have a similar problem. Just so I'm clear, are you saying, that by cleaning the grounds and changing the fuses, you improved your spark, which in turn improved your power?? My spark plugs are white as a ghost, which means they are running lean, which leads me to believe that they are getting plenty of spark. Am I looking at this the wrong way? The car ideals fine and runs good over all, but it really sucks when I hit the slightest hill and it loses power just like yours did. I plan on doing what you said you did, it can't hurt. What all grounds did you clean, and what do you think really made the difference, the grounds or the fuses?

BTW. I read your other post, 7mpg plus. but it left me a little confused with all the things you did, It wasn't clear about what helped and what didn't help!
My plugs always looked great also. It's more than just the spark. It's everything. I really don't know how to explain it. I just know that the day I noticed my alternator bolt had backed out was the day I had hope. Like I said it still isn't perfect. But I have gone through full tanks of gas, in a row, going cross country without having get out of cruise control, put my foot down, turn ignition off and on, hit the ect button, pump the gas pedal a million times a minute. My windows even roll up and down as if they were brand new from time to time. And my battery turns over as if it were brand new also.

Added a second ground from battery to firewall. (long time ago. helped, but not really. Still good to do this though)
Added a ground from the battery to the alternator mounting bolt. This required me to buy a longer bolt. This originally was a wire that I added at the same time as the other and was originally going from battery to the block, screwed into the engine lift bracket in between the plugs and the alternator. I moved it to the alternator because.... well just because.
I cleaned the ground terminals on the throttle body, transmission, and the main ground. Pretty much any thick ground wire I could find.
I wire brushed where the alternator touches the motor.
I replaced the main fuse that I blew. (still need to replace the other two. Quite possible this will be the final fix. ill let you know. Plan on doing it wednesday).

I did so much other stuff that was suggested on here. That 7 mpg post is not the only one. And none of it helped. I always thought it did. But it ultimately was just one of those times the car wanted to run right.

The biggest difference, or at least when I was able to go multiple tanks was when I replaced the middle fuse on the battery. Fixing the grounds would guarantee me at least half a tank of decent driving. I would say I have issues one out of every four tanks. I also try my best to put chevron, phillips 66, centex, or valero gas in. I had good luck with sheets in the northeast. I seem to run best on those. Shell is good too, but not great. I don't worry about higher octanes anymore either.

I know your pain. So I'm happy to help with anything I can.
 
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