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2G Need some serious help. Timing belt slipped off?

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ChristianPastor

Probationary Member
15
7
May 28, 2022
Superior, Wisconsin
Hello all,

Got a unique issue here that I need advice on. My coworker has a 1997 eclipse turbo. We were in the parking lot at work, looking over the engine and BS'ing as car guys do. We somehow notice the belt on the cam sprockets seemed "not as tight as it should be" and I accidentally pulled it off!

For how easy it seemed to come off, it was a bear to get back on. We were trying everything. We moved with difficulty one of the cam gears (closest to the windshield) A tiny bit in an attempt to get it back on with no luck. Stupid I know.

We finally got it back on. The car doesn't start now. Obviously I suspected the timing was off. I looked up the correct timing for the cam gears. We have both dowel pins in the 12 O'clock position and the timing marks facing each other. The strange part is the mark on the one cam sprocket moves once the belt is put on and the engine turned over (again the cam gear closest to the windshield). I noticed upon taking the belt off again that when lined up, the sprocket in question has a bit of play (2 or 3 teeth worth in a clockwise direction from the 9 o'clock position but not counterclockwise which then causes the mark to be of from the correct 3 and 9 O'clock position which causes the timing marks to not line up again when trying to turn the motor over. Basically the one sprocket goes to the 10 o'clock position. Can we set the sprocket back to say just below the 9 o'clock position so that it "settles" to the correct 9 o'clock position once the belt is back on and the engine turned over?

Am I over thinking this or? I know nothing about these cars which is the problem. I just hope nothing got ruined in the process of being stupid. Thank you for any advice you may have.
 
I don't think that's totally unreasonable. The labor rate might be $100/hr. Here's the process from memory:
1. Remove accessory belts.
2. Raise the left front wheel and take it off.
3. Remove the plastic splash shield.
4. Support the front of the engine and remove the front engine mount. (Timing belt goes around it.) You can skip this step if keeping the old timing belt -- only recommended if brand new.
5. Remove the crank pulley and vibration damper.
6. Remove all three pieces of the timing belt cover.
7. Remove the timing belt.
8. Unless it is new the #2 toothed belt that drives the upper balance shaft should be removed/replaced. If this belt fails it can take out the timing belt ...
9. Check out the timing belt tensioner. Since the timing belt slipped off easily, it is at least suspect. Minimum would be badly out of adjustment. If in doubt replace it, ditto the idler pulley. The tensioner also requires adjustment but I don't remember those steps -- 10 years since I did that job.

Consider also replacing the water pump (not a big job) and the oil pump (bigger job) at this time.

Now you can replace the timing belt itself. This involves correctly positioning the crank sprocket, both camshaft gears, and the oil pump sprocket and you must remove a plug in the block to be sure about the oil pump sprocket -- it drives the lower balance shaft via 2:1 reduction and no outside mark assures correct placement of that shaft.

When you get the belt on and everything's tight turn the engine over a couple times and be sure the marks are still correct as it's easy to make a mistake and be off a tooth due to slack in the belt.

Then reverse all the above. 14 hours for a skilled mechanic? Wouldn't surprise me a bit. Personally I'd set aside a week of part time work and I'd call myself mid-grade skilled.

THE ABOVE IS FROM MEMORY -- Look it up in the book for the real info! The shop manual is online here.

Since reading your story I have tried the experiment on both my 4g63 cars. I cannot slide the timing belt off the pulley on either one, in fact I can't even get it against the timing cover. So I think that tensioner was pretty far off and that your friend's engine was not far from flipping a loop of belt over a tooth on the exhaust cam. That leads to a sudden loss of power and is your last warning that the timing belt area needs attention.
I really appreciate your info! I too suspect the tensioner was not in good shape. I should have the rebuilt head by this week and I already have all the gaskets, tensioner, and a new belt. I'm going to follow the vfaq step by step. Taking my time, and double checking everything, I should do ok.
 
In 1995 I billed 600 for this job as an amateur mechanic. This included parts and the water pump. 1400 is probably just the belt, not r and r head.
Ok an update. Got the head back from Rix and put it all back together. Timing was easy. Head went on no issues. I have idle surging issues. Can't find a vacuum leak ANYWHERE. Gaskets have been checked and all good. Car runs good at higher rpm. No codes thrown. Constantly surges between 900--1600 rpm. Car in gear idles at 1250ish. My assumption is air entering from somewhere but no idea how to proceed. Do you have any suggestions? Thank you in advance. You guys are a wealth of knowledge.
 
Ok an update. Got the head back from Rix and put it all back together. Timing was easy. Head went on no issues. I have idle surging issues. Can't find a vacuum leak ANYWHERE. Gaskets have been checked and all good. Car runs good at higher rpm. No codes thrown. Constantly surges between 900--1600 rpm. Car in gear idles at 1250ish. My assumption is air entering from somewhere but no idea how to proceed. Do you have any suggestions? Thank you in advance. You guys are a wealth of knowledge.

Glad to see you're making progress with this!

The obvious question is: Did it idle correctly before? If so then, yes, an air leak is likely. The ECM will cut off fuel on idle that goes above 1500 so that's what's causing the surging.

Have you gone over it all with a can of starting fluid looking for the leak? You probably had the TB off; the joint to the plenum is especially problematic if you've got a bad gasket or the wrong one. Or if a flange is warped. If it leaks along the bottom starter fluid may not find it; try a mechanics stethoscope looking for a whistle or other wrong sound.

Any chance the throttle cable isn't adjusted right and is holding the throttle open a little? If both of those are okay take a screwdriver (either type works) and crank the BISS screw in counting turns until it bottoms. If that's over about 2 turns it was too far open and you should see if the idle can be brought under control using that adjustment. About 1-1/2 is normal I think.

Try clamping the various vacuum hoses.
 
Check the injector seals also since they can be a problem when messed with.

A boost leak test maybe an easy way to find a leak if you have access to the tools to do it. I’m sure you don’t want to spend any more money making a tool, so the above suggestions might be better.
 
Ok an update. Got the head back from Rix and put it all back together. Timing was easy. Head went on no issues. I have idle surging issues. Can't find a vacuum leak ANYWHERE. Gaskets have been checked and all good. Car runs good at higher rpm. No codes thrown. Constantly surges between 900--1600 rpm. Car in gear idles at 1250ish. My assumption is air entering from somewhere but no idea how to proceed. Do you have any suggestions? Thank you in advance. You guys are a wealth of knowledge.
Did you at least try setting idle per the manual?
 
No I didn't. My ignorance is showing here. I didn't know I had to reset the idle. Would you kindly point me in the right direction?
Did you at least try setting idle per the manual?

Check the injector seals also since they can be a problem when messed with.

A boost leak test maybe an easy way to find a leak if you have access to the tools to do it. I’m sure you don’t want to spend any more money making a tool, so the above suggestions might be better.
Thank you I will check again.

Glad to see you're making progress with this!

The obvious question is: Did it idle correctly before? If so then, yes, an air leak is likely. The ECM will cut off fuel on idle that goes above 1500 so that's what's causing the surging.

Have you gone over it all with a can of starting fluid looking for the leak? You probably had the TB off; the joint to the plenum is especially problematic if you've got a bad gasket or the wrong one. Or if a flange is warped. If it leaks along the bottom starter fluid may not find it; try a mechanics stethoscope looking for a whistle or other wrong sound.

Any chance the throttle cable isn't adjusted right and is holding the throttle open a little? If both of those are okay take a screwdriver (either type works) and crank the BISS screw in counting turns until it bottoms. If that's over about 2 turns it was too far open and you should see if the idle can be brought under control using that adjustment. About 1-1/2 is normal I think.

Try clamping the various vacuum hoses.
Yeah I scoured the car with starting fluid. Every single gasket connection but I see how I wouldn't be able to tell necessarily on the very bottom. I'm going to check out that joint that you mentioned that tends to be problematic and get back to you. And yes it did idle okay before so it's obviously something that I did on the install. It's just driving me crazy. Thank you for all your help so far, I really appreciate it;
 
Glad to see you're making progress with this!

The obvious question is: Did it idle correctly before? If so then, yes, an air leak is likely. The ECM will cut off fuel on idle that goes above 1500 so that's what's causing the surging.

Have you gone over it all with a can of starting fluid looking for the leak? You probably had the TB off; the joint to the plenum is especially problematic if you've got a bad gasket or the wrong one. Or if a flange is warped. If it leaks along the bottom starter fluid may not find it; try a mechanics stethoscope looking for a whistle or other wrong sound.

Any chance the throttle cable isn't adjusted right and is holding the throttle open a little? If both of those are okay take a screwdriver (either type works) and crank the BISS screw in counting turns until it bottoms. If that's over about 2 turns it was too far open and you should see if the idle can be brought under control using that adjustment. About 1-1/2 is normal I think.

Try clamping the various vacuum hoses.
Ok. The idle changes when the fuel injector o-rings were sprayed with starting fluid. Looks like I know where to start. Hopefully that's all it is. The car was running super rich/black smoke out of the exhaust and crappy surging idle.

Check the injector seals also since they can be a problem when messed with.

A boost leak test maybe an easy way to find a leak if you have access to the tools to do it. I’m sure you don’t want to spend any more money making a tool, so the above suggestions might be better.
They are leaking! Thank you. I shall replace the seals
 
Ok. The idle changes when the fuel injector o-rings were sprayed with starting fluid. Looks like I know where to start. Hopefully that's all it is. The car was running super rich/black smoke out of the exhaust and crappy surging idle.


They are leaking! Thank you. I shall replace the seals

Of course the problem can't really be the 0-rings. They're up at the fuel rail and under fuel pressure. Your problem will be the rectangular cross section seals at the lower end which is under vacuum. These are subject to engine heat, they can crumble, pick up 'junk' when injectors are removed/replaced, etc.
 
Of course the problem can't really be the 0-rings. They're up at the fuel rail and under fuel pressure. Your problem will be the rectangular cross section seals at the lower end which is under vacuum. These are subject to engine heat, they can crumble, pick up 'junk' when injectors are removed/replaced, etc.
That's what I meant. Thank you for your help with all my questions.
 
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