Losing power

Hello, just joined today. I heard about this 4runners.com is a great source of information. Well, I have 1994, 4runner, auto, 3.0L, loaded. My runner was running great but lately, it seems like its losing its power in the freeway. I pushed the accelerator all the way down to the floor and it can only go to 60MPH. Also, going up it slows down to 45MPH and the RPM is about 4500. Any idea?

 

When was the last full tuneup and fluid change done?

 

Just replaced the plugs, wires, rotor and cap recently. I'm in the process of replacing the the transmission fluid/filter. But, I'm having a hard time taking the transmission fluid pan. Took all the bolts but still the pan won't come off.

 

Maybe the gasket melted to the trans? Not too experienced with autos, but would suggest taking a screwdriver and giving it a little pry. It is possible that someone used rtv in there and if that is the case a little prying will be necessary. Just don't scratch the mating surfaces

 

Not sure on the old 4runners but Toyota likes to use FIPG (Form in Place Gaskets). They are like RTV, but personally I'd try to find the Toyota one because RTV can be hard to get a perfect seal if you haven't use it before. If you're good with it, should be fine.

Also, check a few other things.

Throttle Body, clean that out.
Air Filter, check for restriction.
Fuel Filters / Pumps.
Spark plugs / wires / distributor. (oops you already said this)

Typically engines need Spark, Compression, and Fuel. It's usually one of the three. I count airflow in the compression part, and recently my sister in laws 2003 camry with 300,000 miles was idling rough, dying at low rpms (traffic lights), and it ended up being the thottle body was so nasty that the butterfly wasn't closing or opening right. Cleaned it, and off they went.

 

Thanks for the input. Air/fuel filters were replaced early this year. I'll check the throttle body.

 

Make sure you clean with the correct chemicals. Crc throttle body and intake cleaner works pretty well. Used it on my buddies tacoma and it did the job. Going to be using it on mine later today probably

 

Guys, thanks a lot. I pry the pan with a screwdriver and it is off now. However, I encountered another problem, I can't take the pan all the way out due to the cross bar. Do I have to take the cross bar out? Need some advice.

 

I had 2nd gen way back in the day. I had similar symptoms on mine and when I took it in they said all the injectors were drawing in dirt from somewhere and getting clogged. If I remember right they replaced all the injectors and fuel rail. That was 12 years and about 3000 beers ago so I'm not 100% sure if remember that all correctly though... good luck!

 

I have no clue on the cross bar since mine is manual, but it does sound like it needs to be pulled off. Should just be 4 bolts so its an easy removal.

Only 3000?

 

I'd pull the cross bar. You want to clean that pan out well, and the only way to do it right would be to have access to it on the ground. Just note which screws go where, and if you can't find a manual to note how much torque to put back on the screws when re-installing, then google it. Don't get all paranoid about it, but I want to keep things bolted on while I'm driving I use a good bit of blue thread locker, or anti-seize depending on what I want and what the manual calls for.

 

Thank you all for your good comments. I got the cross bar out and cleaning the pan now. I'll change the trans filter and I'll go for a test drive after. I'll let you know the outcome.

 

Any update on this? How are things doing?

 

It took me a while to put everything back. To summarize all the work that I did, new plugs/wires/cap/rotor. Cleaned the the throttle body. Replaced the MAF and transmission filter/fluid. I conclude that the problem is still there. I don't see/feel any improvements. It is very slow on acceleration. Just a slight inclined road, it is very slow and gas pedal is all the way down and the 4000RPM. Appreciate any suggestion?

 

I'm swinging wildly a bit here but have you checked the compression?

 

I didn't the compression test yet. I'll do that this week-end. In the mean time, I'll put some injector cleaner and see if it will help. The fuel filter that I have in there now, maybe it has 5,000 miles. So I think fuel filter is still OK.

 

You got a lot of tailpipe smoke? Does your oil in your dipstick look milky? Are you having to refill any fluid regularly, like coolant?

 

^^Head gasket??

 

He hasn't responded, just basically yes, I'm asking him to check it. Hopefully that's not the case, but he's checked most everything else.

 

Hi, sorry for the late reply. No, I didn't add coolant for a long time and I always check the coolant. I changed the engine oil lately. When I drained the oil, it was just old oil, it wasn't milky. The head gasket was changed when 4runners had a recall couple years ago. I don't notice black smoke coming from tail pipe. Next move, will check the compression test this week-end like fajitas21 suggested. Some one told me, maybe the igniter is bad. Is '94 4runner has an igniter? Thanks.

 

I honestly don't know, I don't want to give you mis-information so hopefully someone else can pop in.

 

Any ideas/recommendations/comments would be appreciated. Thanks.

 

Did you try the compression test this weekend? Any results? Any particular cylinders not as good as the others?

 

Hi fajitas21, I don't have a compression tester, so my friend will do it on the 2nd week of September. Is 170 - 180 psi is suppose to read?

 

That's probably in the neighborhood. From what I understand it's more relevant if all 4 or 6 cylinders read near the same PSI, regardless of it. For example if 1, 3 and 4 were at 150, 165, and 158 (respectively), and #2 was at 125, that's not good. The 150 - 165 isn't too bad because it's clumped up, but that 125 being so far off is a sign of a ring not sealing well.