thissilentstar

I have owned a 92 3.0 4runner for about 2 months now. I changed the spark plugs, fuel filter, pcv valve, air filter, thermostat, O2 sensor. Cleaned throttle body.

Anyways, it has gotten colder since I bought it, and sometimes have to give it some gas when starting in the mornings. I let it run for about a minute, then drive 10 min. to work. Here is my problem... when I press the gas the rpm's drop-the car almost stalls, it hesitates and then will go. It does this at all the stoplights. I think it just does that when it is cold, but I have only been driving it a few miles everyday.

There is also a lot of oil underneath the car, and dripping so there are about 4 different spots on the cement after parking it. I added 1/2 a quart of oil about a month ago, and checked the oil a few days ago--and it is still right where it should be. So maybe some sort of slow leak?? I am not sure where it is coming from, but could be that one of the valve gasket needs to be replaced. I don't know if they leak that slowly or if there is something else that can leak oil. Not sure! There is also NO oil pressure. Once in a while the gauge will go up slightly, but nothing worth mentioning.

I understand it could be quite a few seperate issues. I am just wondering if the oil pressure, leak, and the stumbling/hesitation could be all related. No codes are being thrown.

If it is just doing it when it is cold, could that just be a coolant temp sensor or something? or TPS?


How do I clean the oil off, so I can watch and figure out where the leak is coming from?

I think that is it, if someone has any advice let me know. I told someone that I would have some pics of the 4runner up, but I never was able to take any. (it has been very cold..!)


Thanks a lot for any suggestions or help! I have searched quite a bit for this on the forums. So I have quite a few places to start, but just wondered if these things could be related at all. I know there is a lot of info in the forums about all these issues separately, so feel free to say "they are not related!" and I will just use the stuff already posted. (I realize it is annoying reposting the same things over and over again-)

toytech76

Your ISC valve may be the culprit for your bad running when cold. Does it run ok when the eng warms up completely? Does the eng warm up all the way? I think that issue may affect your oil press reading. If its barely running it wont read much pressure. To get a true reading on your pressure you need to hook an actual psi gauge to the port your sender is screwed into. Make sure your oil level is correct. If your leak is from your valve cover gaskets, adjust your valves while you have them off. Also replace the rear cam plugs as they leak just as much. Get a good degreaser and spray the eng and underside then wash it off with a power washer, taking care not to get water in the dist or anywhere it shouldnt go

thissilentstar

Yeah, it only stumbles when it is cold. When it gets up to temp, it works fine. It's just wierd, cause the rpm's drop almost like the fuel pump shuts off for a second and then comes back on. It does not jerk or anything though. I searched a bit and found out about cleaning the isv or whatever it is called. I am sure that is a good thing to do, even if it is not the problem. And it may not be-- it idles fine, and when I press the gas when in park--rpms go up just fine. Nice and strong. We'll keep figuring it out. I have not changed the rotor, cap, or spark plug wires. Could a bad rotor do that? Just curious, thanks for getting back to me-

thissilentstar

So.. I bought some sea foam and that seemed to make my situation worse. Stumbles--almost stalls at stoplights. I replaced the cap and rotor the other day, just for the sake of doing it.

I also took off the oil cap and there was no vacum there at all, idle did not change either...

Took off the spark plugs---oil and almost fouled after only 2 months!


Here is my normal day with it...

Starts right up (even better since the sea foam). Idles fine (although it has developed a slight knock since the sea foarm). I can rev it and the rpms go up, seems to have power.

I put it in gear to do my 10 minute drive to work. Drive until the first stoplight about 100 yards away. Stop and turn right. When I press the gas the car seems to almost shut off, the rpms drop and then they slowly come back up and I start to move. But I move very slowly!!

It is like this all the way to work, but as it gets heated up, it starts to run better, accelerate better, and does not stumble anymore by the time I get to work.

Gas mileage has gone down so much! like 100 miles to a 16 gallon tank.


Could this have to do with bad rings or a valve gasket leaking? Then when the engine gets warmer, the rings expand enough to allow better compression--and so then it runs great? Or could it be some sort of fuel pressure thing, where it is not getting enough fuel until it builds up pressure as I drive? When I replaced the fuel filter a few weeks ago, barely any gas came out of the line. When I have done this on other vehicles I ended up covered in gas!!

Any help would be great! I am going to buy a compression tester, test them warm, then test them again when it is cold to see the difference. And also do a leak down test while I am at that. Should I sea foam it again even though it made it worse last time--- seems like it needs more treatments if it just got worse last time.

nate V

you can use GUNK to clean the oil off your engine to see where it is leaking from.

It could be that you are burning a lot of oil is the smoke blue?
If its leaking too much it wont allow the crank case t build up pressure. also check your oil level.

thissilentstar

Oil level is fine, and those spots that were showing up underneath on the cement are gone. I am not too concerned about the oil thing unless some sort of leaky gasket could be the cause of no power. Or if my rings are bad that would be the cause. When the car gets warm, then it is fine--- would the rings expand enough by then that there is enough compression?