HELP!

[puma]

Some of you may remember me and some of you may not, but I have been attempting to restore an '87 palmero grey starion for quite some time now. I have rebuilt the engine and throttle body and it runs!!

 

But,... I still am having some issues (of course), and I need help bad because at this point I am totally lost...

 

I know the car is running rich and I thought it was because I had bad mixture screw in the throttle body... then I thought maybe its because I need to replace the water temp. gadge which would impede the car from recognizing its temp so it dumps more fuel... ( right?) but after replacing such parts its still running rich...

 

I need help and I am not sure where to begin...

 

Help?

 

-Dani

[JustPaus_88TSi]

Long time no see.

 

 

You're definately on the right track.

 

Why do you think it's rich? Watery eyes while driving, very poor fuel mileage, gas droplets from exhaust, fouling sparkplugs FAST etc.?

 

How can extra fuel find its way into the motor?

 

A faulty CTS(coolant temp sensor) that doesn't tell the ECU that the motor is warm enough for closed loop operation. You mentioned something to this effect, but might've traveled down the wrong path when you mentioned the temp gauge in the same context. The temp gauge has it's own sensor, seperate from the ECU specific temp sensor. In short, you might've been "right there" but replaced the wrong sensor.

 

I'll have to find the picture that labels each sensor on the intake manifold, so we can find out which one exactly you replaced. There's a couple quick ways to find out if the ECU's CTS is bad.

a. Check the ECU's error codes with a simple 12V LED and two alligator clips(look like roach clips). The parts can be found at any radioshack for under $3. Also, the link for checking the error codes: LINK!

b. Unplug the connector from the CTS and jump the two terminals with a 300ohm(I think that's the value used) resistor. Once "jumped" with the resistor, this will tell the ECU that the motor is warm. If it drives better, then there ya go.

c. Refer to the FSM(factory service manual) for troubleshooting the CTS.. It'll tell you to test the resistance of the unit while cold(76* or whatever) and again while it's at roughly 180*. The FSM tells you to remove the CTS, heat some water to 180* or whatever and then test it. I wouldn't bother with all that, you can just drive your car around a bit until it gets up to it's normal temp range, go back home(park the car, motor off), pull the CTS connector and test the sensor that way.

 

 

 

 

Other things can make you run real rich. Such as leaky injectors, weak spark, bad FPR and a faulty MAS.

 

But let's knock one thing down at a time, makes it easier.

[puma]

A faulty CTS(coolant temp sensor) that doesn't tell the ECU that the motor is warm enough for closed loop operation. You mentioned something to this effect, but might've traveled down the wrong path when you mentioned the temp gauge in the same context. The temp gauge has it's own sensor, seperate from the ECU specific temp sensor. In short, you might've been "right there" but replaced the wrong sensor.

 

I'll have to find the picture that labels each sensor on the intake manifold, so we can find out which one exactly you replaced. There's a couple quick ways to find out if the ECU's CTS is bad.

a. Check the ECU's error codes with a simple 12V LED and two alligator clips(look like roach clips). The parts can be found at any radioshack for under $3. Also, the link for checking the error codes: LINK!

 

I figure its running rich by the smell its emitting since I got it running again. Though it runs, it does not run well... It also has trouble idling. With my very limited knowledge I am just grabbing at straws at this point... but hey, at least I am on the right track.

 

So, I when I get off of work tonight I will check the ECU error codes and go from there.

 

Thanks for the help and kindness as always its greatly appreciated.

-Dani

[Dcrasta]

Try this.

 

On the mixer you have a black and a green (or blue) injector. Disconnect the 'green' injector and start the car. Does it start? If not you have the wrong injector connected to the 'primary' injector circuit. It should idle and rev(drive) up to about 3-4k rpms with the green injector unhooked.

[Wolf87Conquest]

Your post stated a new rebuild.

You might not have the timing correct, it should be 10 degrees before TDC.

I'd also check vac lines..good condition and hooked up correctly.

Does the advance work properly inside the distrib? Vac advance as well?

How long since the oxygen sensor was replaced?

Injectors leak? Hooked up correctly? (black near fender is primary, blue or green towards engine is secondary)

Fuel return lines clear?

Check FPR for proper function.

The coolant temp sensor for the ECU is the one on the intake close to the oil dipstick...it stands straight up.

The one near the thrmostat housing is for the temp guage and seperate from coolant temp sensor.

[Lusion972]

Your lucky, I'm running broke

[mikec]

Hey Dani, glad to hear you're still in the StarQuest scene.

 

Running rich comes from many sources as you can see from the other replies.

* Leaking fuel injector(s)

 

* Leaking fuel pressure regulator - any gas in the small vac hose at the bottom of it? If so, the regulator is bad.

 

* Fuel return hose from regulator back to gas tank is pinched, blocked, or otherwise restricted. That prevents the fuel pressure regulator from doing its job.

 

* ECU coolant temp sensor (the 2 pronged one on the intake manifold near the oil dipstick) reads too much resistance on a warmed-up engine... keeping the ECU in choke mode. And as Wolf87Conquest noted, it's a different sensor than the stuff that drives your dash temp gauge. On a warmed-up engine it should read under 300 ohms if it's working right. A 220 to 270 ohm resistor from Radio Shack can be stuffed into the connector instead of the sensor as a quick test.

 

* Bad or incorrect airflow sensor. The StarQuest one has two plastic bypass tubes as part of it - both tubes should be wide open. Other Mitsu cars had smaller tubes or one/both tubes blocked.

 

* Air leaks anywhere between the air filter lid and the throttle body. Any air that gets through is "unmetered" by the airflow sensor so the ECU commands the wrong amount of fuel. That can lead to misfires (too little fuel to actually burn right... so you get unburned gas in the exhaust) or too much gas if the turbo is spinning pretty quickly, blasting air out a leak. That air being pumped out was measured by the airflow sensor so the ECU figures that much air went into the engine so the ECU commands that much fuel too. With the engine idling, you can spray the air hoses, connectors, intercooler, intake manifold, manifold gasket, etc. with spray carb cleaner. If you hear ANY change in the idle (better or worse) you've found a leak. While testing a newly rebuilt engine, you can undo the various vac hoses/pipes going to/from the throttle body, intake manifold, etc. on the 87-later cars. Plug every opening and plug the hose too. You don't need any of them to get a proper idle. Don't drive this way though.

 

* Mis-adjusted valve or jet valve clearances. These will cause low readings on a compression check.

 

* Mis-timed main engine timing chain. This causes the camshaft (and thus the valves) to be out of sync with the crankshaft. Use a big wrench to turn the engine crankshaft pully bolt (clockwise only as you face the front of the engine) until the timing notch on the rear-most pully lip lines up with the "T" on the timing cover. Now pop the valve cover off and look at the camshaft sprocket - look for the roll/shear pin that ties the sprocket to the camshaft. It should be at 12 o'clock or slightly before (counterclockwise) if the chain is installed correctly.

 

Is the lid on your airbox tight to the canister? That made a big difference years ago when we added those little clips. There is also a cork gasket between the lid and the airflow sensor itself; if it's bad the airflow sensor doesn't work right.

 

mike c.

[puma]

So I go out to check my CTS and discovered that there was need to test it because the wires were not attached to it... So I figure that was the problem. I uninstalled the piece and took it into the dealership which I will get on Monday. Hopefully this will be one of my last problems.

[puma]

Your post stated a new rebuild.

You might not have the timing correct, it should be 10 degrees before TDC.

 

We actually thought this was the issue for awhile, but the timing is correct.

 

I'd also check vac lines..good condition and hooked up correctly.

 

They are in good condition as that has all been replaced, but I did have some hosing eliminated... and so to best of knowledge all the hosing is fine.

 

Does the advance work properly inside the distrib? Vac advance as well?

 

This is something that I am not sure of and will check when I install the new CTS.

 

How long since the oxygen sensor was replaced?

 

Replaced it when I rebuilt the engine so it is brand new.

 

Injectors leak? Hooked up correctly? (black near fender is primary, blue or green towards engine is secondary)

 

Injectors are not leaking and are properly hooked up.

[puma]

Hey Dani, glad to hear you're still in the StarQuest scene.

 

Is the lid on your airbox tight to the canister? That made a big difference years ago when we added those little clips. There is also a cork gasket between the lid and the airflow sensor itself; if it's bad the airflow sensor doesn't work right.

 

mike c.

 

That is actually the first thing I checked when I attempted to start it. I found that its hosing wasn't even connected as well as not having the clips we put on it a couple years ago. I am sure I am going to be finding a lot of these types of problems.