Poor Engine Idle & Running Issues

[Nastyleggyss]

So, I have recently finished a install of a TD04 and 06-07 tmic in my 230k mile 92 leggy ss.

While replacing some gaskets i decided to pull the motor and install the turbo and top mount, with a act flywheel also.

My problem is this.
Initially during warm up the car ran with a high idle. After warm up it then proceeded to drop down to 200ish rpms, so then since i made such a large change with the car i decided to turn up the idle. It seems to be running pretty rich(better than the alternative). It idles flawlessly. But as soon as you try to go anywhere it seems to fall on its ass and not accelerate. It actually goes faster in reverse than forward gears.

My thoughts could be old gas, or maybe i screwed up the fuel lines.... which would be odd because it seemed to throttle up fine during warm up.

Any other ideas?

[PhyrraM]

Assuming you've already checked the mechanical stuff (timing belt/vacuum leaks/etc) the first things to check are the throttle position sensor/idle switch adjustment and coolant temperature sensor. Those have the biggest effect on drivability.

Also because of the age of these cars, many times disturbing the cam/crank/knock sensor plugs causes problems....they get really brittle and break (sometimes unseen) when the engine is removed.

[Nastyleggyss]

I did replace the knock sensor before pulling the motor. I think the wire of that was pretty sketchy. On the car side of the plug anyway.

[Nastyleggyss]

Wouldn't anything like that throw a code? I was surprised that there was no cel on after a while.

[Legacy777]

How did you adjust the idle? You really shouldn't mess with the stop screws on the throttle body as that can throw it out of calibration with the TPS.

Sometimes the lightweight flywheels will cause some poor idling. I would recommend double checking to make sure you don't have any vacuum leaks.

Sometimes you will get a code....and sometimes you won't. The older ECU's are not as good in performing diagnostics.

[wtdash]

Hi,
Just to double-check the car ran perfectly fine b4 the upgrades, correct?

What gaskets were replaced?

Nothing you added would affect the idle, etc - BUT if you now have a vacuum leak due to either a hose not connected or cracked, you'll have issues.

If you read thru the numerous posts on here from people who've done the TD04/TMIC upgrade many had vac line issues.

GL,
Td

[Nastyleggyss]

I did use the stop screw. I'll adjust it back and see what happens after that. And I'll pop the intercooler off and check the wires. If anything it has to have less vacuum leaks now. I drove it for like 15k without a hose clamp on the old plastic tube from the turbo to the tb. I made sure all the hoses fit snug and had decent clamps. I just recently replaces vc gaskets, turbo gaskets, pan, and was going to do rear main, but found it was the little plastic cover with screws behind the flywheel. It did run good before the swaps. Although it was throwing numerous codes and sat for a bit apart and before.

[Nastyleggyss]

Just drove it around after adding some fresh 91 oct.

Accelerates fine. Drives good. Brake pedal doesn't hit till the floor, although I'm sure that's nothing to do with my issue.

After warm up, the car still stalls after 3000-3500 rpms and won't go after that. Can hear the turbo spool and whatnot but she is dead in the water in terms of accelerating. I really think it may have something to do with the knock sensor and wiring. Any other ideas?

[wtdash]

If KS is an issue it should throw a CEL. But I do know what you mean about the wiring as I've had replace 2 of them (search on here for microphone wire) due to the wiring just wearing out @ the plug.

TD

[Legacy777]

Do you know how to use a multimeter to check wiring resistance? I would recommend checking the knock sensor's wiring from the engine to the ECU to make sure it's good.

Also, since what you've described sounds like it runs ok when cold, but doesn't when hot; temperature related issues can sometimes be caused by the coolant temp sensor. Do you know how old yours is?

[Nastyleggyss]

I don't! Could ya help me with some simple directions?

In regards the the temp sensor, I have no idea. Is that under the tb by the ks?

[Legacy777]

Here are some links with some general info on how to use a multimeter

http://youtu.be/zb7WHaL_dz8

http://www.sciencebuddies.org/science-f ... rial.shtml

Yes, the temp sensor near the knock sensor

http://main.experiencetherave.com/subar ... P_5115.JPG

A better view here (it's the one with the brown connector).

http://main.experiencetherave.com/subar ... G_4027.JPG

[Nastyleggyss]

Well I bought a ks and coolant sensor. Tomorrow or Sunday I'm going to check some things.

[Nastyleggyss]

Started her up today and she threw a code. The cel was knock sensor so I just put mine in. After warm up it still won't accelerate after 3750rpms now. The cel is gone.

I have a coolant temp sensor that I'll be putting in also now. The car is very warm and fans are not coming on, but when the cars being driven it should be cooling still. I'm lost. Can the computer shut it down if the temp sensor is bad and sending incorrect info?

[Legacy777]

If the coolant temp sensor is sending bad data to the ECU, the engine could run very poorly. I would suggest putting the new coolant temp sensor in and see how that affects things.

[Nastyleggyss]

No change. Now I'm just throwing new parts at a car for no reason.

[Nastyleggyss]

I'm out of ideas. Now what? I'm letting it sit with the battery terminals off to clear the memory, then I'll check again.

I have no idea what else it could be. There is no way there is a vacuum leak, good sensors, no cels, runs good before warm up.

The only thing I can think of is that there is straight water instead of coolant in it, and there is no way that's doing anything that could cause this.

[Nastyleggyss]

Bad ground on the little black sensor that mounts behind the intercooler?

[Legacy777]

Ok, here's what I recommend you do; download the factory manual from me (if you haven't already done so) and run through the diagnostic & troubleshooting section (2-7). If you can get a code to come up with the active diagnostic check with the green connectors that would be helpful, but you may not get a code. Have you used a multimeter to check the wiring resistance of the knock sensor or some of the other various sensors?

http://www.main.experiencetherave.com/s ... and_Elect/

[Nastyleggyss]

Did the active diagnostic and got codes for maf and injector 3. Still slowly dies after warming up until it doesn't have power to move the car. Flooding!? Won't rev over 3000rpms. Odd. Help please?

[Legacy777]

Refresh my memory, but have you cleared the codes and see if those same codes come back?

Have you checked the resistance of the injector? It should be around 11-12 ohms.

I'd start with that, and maybe swapping in another injector to see if it clears that code. If it does, then I'd also look at another MAF or cleaning it if you haven't (only use MAF cleaner)

[Nastyleggyss]

I checked and got those after clearing the codes, but I can clear it again. I'll check the ohms

[Nastyleggyss]

Well, just checked injectors. All between 11.8-12.1ohms. All good. Took vacuum line from turbo and ran it to the wg and same issues. Threw code for atmospheric because of it. Have codes 22, 23, 45 and 49 now. Maybe going back to stock will have to happen. Idk

[Legacy777]

The codes you listed that came up, did those come up with the black diagnostic connectors or with the green connectors using the active diagnostic mode?

[Nastyleggyss]

The maf and injector code came up with the green wires. The rest all came up with the black. Knock sensor and some others with the black. Does anyone know a thread with pictures for the knock sensor rewire. Mine ohmed out all over the place so I'm going to try running a new one. Does 3core mic wire work?