Ok, this may be kinda long. I recently posted problems that I had when trying to retime my engine after I replaced the timing belt, and all components. The engine is running great with or without boost. The only thing is it idles a little low sometimes, and it sounds like there is a little rattling noise coming from the tranny. The engine, and tranny have 93, 000 miles on them. I checked the tranny fluid today to make sure it was not low, and when I did tranny fluid came spuing out so I know its not low. By the way it is a manual tranny. When I rev the car it doesn't make any noise when at normal operating temp. So, is it possible to slightly bend a valve when trying to start the engine after I timed it when it was out of time. The engine has never idled like this before. I did a compression check of all 4 cylinders, and all the cylinders read about 170-175psi. The idle on my tachometer reads a good idle, but every once in a while the car will shake and vibrate a little, so maybe its not even the idle???????????Any info or experience greatly appreciated.

Are all your motor mounts tight?

You could always do a cylinder leak down test to see if you bent a valve, however, I doubt you did.

well I will check all my motor mounts, but I did torque them down to spec when I put everything back together. Also, I have never done a leak down test so I guess I could. Is it described in the haynes manual?

another question: Is it possible to have the cam timing just a little out? I took off the valve cover, and made sure the hole in each cam was facing up. Then I did the timing as normal. The engine pulls nice and hard with boost, and everything seems fine, except for the vibration that seems to get better the longer the car runs. From the exhaust note the idle just isn't as smooth as it used to be.

Could be a million things but lets rule out some obvious.

Its not your timing, if timing was your issue it would do it all the time. Judging by your compression, its not a bent valve, your fine there.

Here are a few things to do that should be done regardless of issue or not. Clean your Throttlebody real good. This includes the IAC port and the backside of the throttle plates. This should be done with every tune up and its commonly overlooked. I like to use a can of carb cleaner and old toothbrush. When you put the toothbrush back into your mouth it gives you a tingly sensation.

How low is low? I need some numbers?

When this happens, if your heat on? defroster on? a/c on?

Do you notice the idle changes when the fans kick on?

Do you feel the RPM's raise when you turn the steering wheel?

HOw old is the o2?


Most of these cars do have the small tiny variences in idle, its normal at the electrical items click on and off. We will see if we cant limit it though without replacing the alternator.

ok, the throttle body was bored out and is clean as well as the iac. I scanned for cel's with my obd 2 scanner, and came up with 0403, and 0140. So, my front o2 sensor is brand new, however the rear 02 sensor is old, and it threw a cel once before. I know what the cel's mean so im going to replace the real 02 sensor, and probably just plug the egr up without any vac lines attached since I did the egr block off mod. After I get her back together, and running again I will post the results. Thanks again.

Your rear o2 wont cause that issue.

If the ECU keeps trying to test the EGR setup then yes it can cause that issue.

YOu didnt answer any of my questions....how are we supposed to help if your not going to try?

ok star turbo, yes my throttle body is clean. The idle problem that im having is with nothing electrical on such as lights etc. Also, when the one fan I have connected kicks on it does play with the idle a little but not much, and I do not have the ac, heat, or anything else on when the car is idling. One of the cel's I got I believe says that the o2 sensor bank 1 sensor 2 is not responding? Also, I don't believe when I turn the steering wheel it effects the idle. I believe that has answered all your questions. Thanks.

Also, I forgot that specifically my idle hasn't went any lower than probably about 700rpm I think.

700 is semi normal for an older car.

If your idle doesnt change when you turn the wheel you have a problem with the power steering pump sensor or the ECU is not able to raise idle when it needs to. That needs to be looked into as well. This lower idle may also be attributed to that as well as the EGR issue.

The EGR issue is easy to test. Disconnect the wiring from the EGR solinoid. Now the ECU cant open the EGR to constantly test it. I doubt this is the issue but its easy to test for so why not.

The power steering pump issue, you need to check the connector on the power steering pump, there is a one wire sensor that needs to be connected.

Now going back to your Fan, if this idle anomoly is happening when the fan kicks on, its normal. 150rpm drop to 700 when the fan kicks on is what all of my cars do in the summer. it doesnt hold at 700 but it drops during the fan's startup load.

Terry

Terry, I didnt mention it, but I no longer have power steering pump on the car. I removed it due to the way my turbo is setup. So, the connector is not attached to the pump, but this hasn't been an issue until now. Also, I didn't have the egr connected because I did the egr block off mod as stated earlier. Im about to put my obx wastegate back on because the damn bolt inside the wastegate keeps backing out causing the valve to open and let exhaust escape so I had to locktite the bolt hopefully this works. After I get this done im going to fire the car back up with the egr attached, and see what happens.

Nah, leave the EGR off.....that solves that issue. power steering removed.....solves that issue as well.


Ok the next thing I want to to look into.....the 55mm TB! These can be an issue at times. if you have one available, install the factory TB and see if the problem goes away. I will explain later.

Since you brought up your timng issue and resolved it. When you changed out the timing did you reset the ECU? If you did, have you given the ecu time to learn the idle. In other words hwo long has it been with this issue? Few days or a week? ECU learning should resolve in 24 hours or so.

Well, the idle does seem a little better now. And no I don't have a factory Throttle body available to swap them out. Also, I did have the battery disconnected to reset the ecu. I only drove it for about 20 mins last night, but when I got back home it did seem like the idle was a little better. Specifically, the idle isn't always bad, but I would notice at say a stop sign I would stop and the idle would go up a little bit, then down to maybe at the lowest 600, but would come back up with somewhat of a rough idle but the needle looked to be at 800rpm. Also, one other question could my throw out bearing be causing any kind of weird idle? I think it may be starting to go bad because when the car is cold there is a rattle noise coming from the tranny the engine sounds fine.

Originally posted by Star Turbo Talon
Nah, leave the EGR off.....that solves that issue.

Sorry to butt in on this and i may be wrong but i thought with the egr block off kit you were supposed to leave the solenoid connected right? Or did you mean keeping the egr line off of the intake Terry?

EGR block off you remove the egr valve and plug the head. Remove the line from the Intake and plug that too.

Ya thats what i thought. Thanks