90 Camry with shaky idle - Toyota Nation Forum : Toyota Car and Truck Forums

jthafe · 05-09-2005, 11:20 AM

I have a 90 Camry with a 3SFE engine. At idle the engine kind of shakes a little. I can't seem to nail down a cause. I don't just want to start replacing sensors because I know I could end up replacing them all and still not cure the ailment. Also, when in reverse, the engine seems really low on torque. It doesn't like to back up hills at all. I adjusted the idle speed up a little and the engine seems to run much smoother, but once it warms up it starts to run rough again. It's almost like the engine is having trouble breathing or struggling to get fuel. It can be really slow off the line, but once I get it up to a decent RPM it takes off and the problem just goes away.

This is starting to drive me nuts as I'm sure you can imagine. I thought the problem might be in the distributor so I had a close look at it and the coil casing was cracked pretty badly. I replaced it and it ran better but the idle wasn't affected no I just don't have moisture problems. I've replaced the cap, plug wires and plugs too and no affect. I did notice that the #4 plug tube had oil in it. I have no idea how it got in there. The plug didn't appear to be fould so I don't think it got in through the cylinder. Can the tubes crack? I'm sure that the oil could be the problem by interupting the firing of the plug since oil doesn't conduct very well and once I get it up to a good RPM the missing cylinder could be masked. If it is the tube, what can I do short of replacing the head. The DOHC heads are not cheap. I was going to check again today to see if oil managed to make it back in the tube and if so try to seal the plug in with something that can handle the heat and pressure.

Any ideas or advice is welcome.

Mike Gerber · 05-09-2005, 02:28 PM

Remove the spark plug from that cylinder and clean up the oil down there again. Then reinsert the spark plug. Now pull all the plug wires off the plugs. This will expose the large hex nuts that hold the cam cover on. (I believe they are 32MM but I am not sure on the generation 2.) They also screw the spark plug tubes into the head. Tighten them to spec. I'm not sure what the spec is for a 90, so get a manual and check. This is a common problem told to me by an ex Toyota tech. I had the same problem on my 94 (generation 3) and tightening those nuts to spec cured the problem of the oil in the spark plug wells.

As far as the rough idle, I would start by cleaning out the throttle body. Do a search for "throttle body cleaning" on this site. There are a few good articles available with some very specific pictures. Make sure you clean the back side of the butterfly valve inside there and also where the butterfly valve meets the inside of the throttle body when it is in it's idle position. Clean all 360 degrees of where the valve contacts the inside of the throttle body.

Mike

jthafe · 05-09-2005, 03:43 PM

Thanks I'll take it apart as soon as I get out of this dungeon. I thought the tubes were integral to the head. I didn't know they could be removed.

As for the throttle body, also a good idea. When I start the car the engine runs just fine and then once it warms up it begins to idle rough and shake almost like an older engine that needed the choke adjusted. Could the Throttle Position Sensor be bad or need its terminals cleaned off?

jthafe · 05-09-2005, 03:44 PM

Forgot to ask, can the ISC affect idle too?

DavesterJr · 05-10-2005, 07:55 AM

My 89 has the rough idle too.I just got it less than a month ago and I'm still working on fixing everything.Runs alot better than it did when I first got it.

jthafe · 05-10-2005, 01:43 PM

Does anyone know the spec for tightening the spark plug tubes on a 90 Camry with a 3S-FE DOHC 4 cyl. engine? The only manual I have to go by is a Hanes and it's sorely insufficient. It doesn't even talk about the spark plug tubes except to say that you have to remove the nuts to take the Cam-Shaft cover off.

atobe · 05-10-2005, 01:46 PM

it's suppose to be 25ft/lb but it feels not that tight.. i used 35 and it works too

jthafe · 05-10-2005, 01:50 PM

Thanks atobe! How did you do it? I was going to use two of the nuts, tighten then against each other and then torque the tube down.

Mike Gerber · 05-10-2005, 07:19 PM

jthafe,

35 foot lbs seems too high to me. My generation 3, with the slightly bigger 5SFE engine, was 27 foot lbs. I would go with around 20 lbs, maybe the 25 lbs someone else suggested. Also, you don't need to use 2 nuts. Just tighten them down with the valve cover still on. Do it in 3 equal passes with a torque wrench. Say 8 foot lbs on the first pass, then 16, and then 25. If 25 seems too tight, then stop at say 20 foot lbs. You don't want to crack the cam cover as someone else on this forum did. Do it in this rotation; spark plug tube nuts 1-3-2-4; with 1 being the one closest to the passenger fender. The spark plug tubes should also tighten down when you do this; at least that was my experience. After doing this, drive around for about 1000 miles and then check for oil down there again. If no oil is present, you have fixed the problem.

Mike

88 LE · 05-11-2005, 04:31 AM

Quote:

Originally Posted by jthafe

Thanks I'll take it apart as soon as I get out of this dungeon. I thought the tubes were integral to the head. I didn't know they could be removed.

The spark plug tubes screw into the head. They require a special tool to remove.

Quote:

Does any one know the spec for tightening the spark plug tubes for a 90 Camry?

17 ft. lbs.

Your tighten the 4 nuts that hold down the valve cover, not the spark plug tubes.

You need a 30mm socket.

P.S. Don't double post. I've merged your 2 threads together.

jthafe · 05-11-2005, 10:42 AM

Thanks everyone. I appreciate the advice. I'll get on it as soon as work and weather cooperate.

Mike Gerber · 06-24-2005, 03:39 PM

jthafe,

Did you ever solve your problem?

Mike