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Last efforts before calling the hook...'95 C2, won't start after engine R&R.

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Last efforts before calling the hook...'95 C2, won't start after engine R&R.

 
Old 01-11-2012, 01:25 AM
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TravisB
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Default Last efforts before calling the hook...'95 C2, won't start after engine R&R.

Posting this in a new thread in case someone has an answer but isn't following the time lapse thread..not sure if this is excessive posting or not, but figured I would give it a shot before I admit my very first defeat at a car project..

Long story short, dropped the engine/trans over the holidays to install a clutch/LWF and do the 90k service, seals, etc. Things go well other than some broken bolts. Get it back together, hook it all up, and I don't get much of anything. The fun in my Time Lapse thread starts on post 67 (https://rennlist.com/forums/993-foru...e-lapse-5.html). Here's a quick recap:

- Timing has been checked, checked, and checked again (https://rennlist.com/forums/9172268-post112.html)
- Tried a new DME, as well as a jumper
- All electronics connected
- ISV was cleaned
- Injectors were rebuilt, seem to be spraying ok
- Ignition leads were checked for proper resistance, seem to be getting a good spark
- Cylinder head temp sensor tested ok
- Crank sensor clearance in spec at .80mm
- Checked a few grounds, they all check out
- Hand over the MAF while cranking shows reasonable vacuum
- Have tried starter fluid, reinstalling old plugs, turning over with plugs removed, etc etc.

And here is the best I've been able to get out of the thing:


Bueller...?
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Old 01-11-2012, 03:22 AM
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you need Steve Weiner to chime in , give him a call 503-244-0990
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Old 01-11-2012, 09:27 AM
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Been following, and thinking, gotta be painful!

I remember a story of a new batch of flywheels that did not have the proper trigger in it.

Agree with Mike, sounds like a big vacuum leak, but it should still sputter a little.
Here is an idea to check for a big leak, never had to try: Shop vac on intake. When you turn the vac on, you may hear the sucking around the manifold. Just a wild idea.

Back in school the instructor of automechanics class said "when an issue comes up with a no start, it is probably what you added" What new parts went in?

Crazy ideas, but we are getting desperate to help!
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Old 01-11-2012, 10:20 AM
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Been following and scratching my head. It may be crazy, but the only thing out of place I have noticed was in the photo where you showed the distributor. There was a vacuum line stuck on the bolt on the fan housing. Did this line find it's proper home? Probably a stupid question, but that is all all got at the moment.
Good luck with it.

Emerald
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Old 01-11-2012, 10:58 AM
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hey Travis, I just caught up with your other thread late yesterday...
Sorry you are going through this and wish there was something I could do.

Mike J gave some great advice along the way.
Covered the possibilities pretty well, short of being there to see/test in person

I wish I were there! I really enjoy solving problems and this is certainly a good one.
As others have said, it will be something odd/silly in the end.
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Old 01-11-2012, 11:13 AM
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Are you certain the DME is getting a good RPM signal from the flywheel sensor? The workshop manual gives a test procedure that IIRC you can do using just a volt-ohm meter. Definitely worth checking. For that matter, you should also do every other test there that doesn't require an o-scope. I did the RPM sensor test, and I recall the voltage was a little off from what the manual said to expect, but the test proved its point.

And try to restrain yourself from checking/replacing things you haven't messed with. E.g. it's highly unlikely that your DME would just suddenly fail. Focus on the things you've monkeyed with. You'll get through it.
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Old 01-11-2012, 11:19 AM
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Is everything stock (ECU, ignition, intake etc.)?

If your timing is right, you get spark and fuel you should be able to start the engine, unless the maps are wrong. But since it is stock ECU, that can be ruled out.
Check the intake air temperature sensor. If it is not connected (or broken) your ECU will think it is -40dgr celcius outside and will spray too much fuel and the engine will not start. This has happened to me before.
Is your MAF in working order?
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Old 01-11-2012, 11:19 AM
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And as for the vacuum leak idea, you can stop by Home Depot and get some pvc pipe & rubber parts. And get a tire inflator valve from pep boys. Remove airbox, install your big cap, pressurize, and listen for leaks. Once you pressurize, it'll take several seconds for all the air to escape. If it can't hold any pressure you'll know you have a problem.
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Old 01-11-2012, 11:25 AM
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If the timing was off a little, I think the mixture would ignite but just at the wrong time. You would clearly hear that, which is not the case (at least on the video)
BUT if the timing was off 180-degrees, you'd just push the unignited mixture out of the cylinders into the exhaust and it would not ignite at all... just a thought

Edit: And I say, don't call the Hook! Finish what you started. It will not only pump up your ego (as you didn't give up) but you will most probably also learn something new about these engines.
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Old 01-11-2012, 11:54 AM
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Originally Posted by TheOtherEric View Post
Are you certain the DME is getting a good RPM signal from the flywheel sensor? The workshop manual gives a test procedure that IIRC you can do using just a volt-ohm meter. Definitely worth checking. For that matter, you should also do every other test there that doesn't require an o-scope. I did the RPM sensor test, and I recall the voltage was a little off from what the manual said to expect, but the test proved its point.

And try to restrain yourself from checking/replacing things you haven't messed with. E.g. it's highly unlikely that your DME would just suddenly fail. Focus on the things you've monkeyed with. You'll get through it.
+993 on this. You should get a very small AC voltage when cranking from the flywheel reference sensor. It's easy to check at the DME conector...or even easier at the connector tree on the engine.

Did you set the gap to 1mm between the sensor and the flywheel?
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Old 01-11-2012, 11:58 AM
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There is a difference in behavior if there is a vacuum leak/excessive fuel and timing when failing to start.

With a leak, you crank, the engine catches but then dies (or even stumbles a bit if the leak is small enough). With excessive fuel, it catches , roar, then dies and you will smell fuel.

With timing, it doesn't even catch at all, just crank and crank until you let go of the key and it just stop cranking.
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Old 01-11-2012, 12:00 PM
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A couple of random thoughts....

1. Is there gas in the tank? Fuel pump working?
2. Is everything properly grounded?
3. Did you disconnect the battery? That dumps the memory on the ECU. When I did my LWF swap, the car ran like crap until the ECU re-learned everything. I had to crank it for a while and then the idle was really, really low until I warmed up the engine by driving it around for a bit.

Good luck.
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Old 01-11-2012, 12:47 PM
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Default Everyone is pulling for you...

Let me start by disclosing that I did a very similar project a couple of summers back but am by no means a an expert. You have our best folks chiming in here.

I have been following your thread from the 30,000 ft level. So I am not real close to the details.

If this were my dilemma ... here is what I would do.

1. fuel to the cylinder. Pull a plug or 2, crank the engine for 10 sec or so and see if they are wet. Preferably check the plugs on the intake side. I think they upper plugs...ugh. Not wet then you have a fuel issue.

2. Spark. Make sure the plug is actually firing. Take a couple out. crank the starter and check for a spark on the grounded plug. No spark then ignition issue. 2 man operation.

3. Timing. My biggest fear. I did not mess with mine. If you have 1 and 2 above and the timing is close the engine should at least fire. I did not hear combustion in your video. Check the wires. Are they going to the right plug. There are 12 wires and it is easy to mess the routing up. If you messed with the guts of your distributor I can't offer any assistance.

Stick with it. Be vigilant and good luck!

Bob-
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Old 01-11-2012, 01:13 PM
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Originally Posted by techman1 View Post
Been following, and thinking, gotta be painful!

I remember a story of a new batch of flywheels that did not have the proper trigger in it.

Agree with Mike, sounds like a big vacuum leak, but it should still sputter a little.
Here is an idea to check for a big leak, never had to try: Shop vac on intake. When you turn the vac on, you may hear the sucking around the manifold. Just a wild idea.

Back in school the instructor of automechanics class said "when an issue comes up with a no start, it is probably what you added" What new parts went in?

Crazy ideas, but we are getting desperate to help!

Yes, this has been frustrating! In the back of my mind, I've been worried about the flywheel being the issue. Do the teeth look correct on this? I don't recall there being any skipped teeth either, I guess I didn't compare the old one to this very closely before I installed it.

And the thing with the vacuum leak is..I've been all over this engine, and I can't find a single disconnected thing, loose connection, etc. I don't know what could be just loose and cause enough of a leak to not start. Everything on the intake has been checked several times.




Originally Posted by e3photo View Post
Been following and scratching my head. It may be crazy, but the only thing out of place I have noticed was in the photo where you showed the distributor. There was a vacuum line stuck on the bolt on the fan housing. Did this line find it's proper home? Probably a stupid question, but that is all all got at the moment.
Good luck with it.

Emerald

That's a vacuum line that goes to the heater blower stuff. I've got it plugged up..


Originally Posted by MarkD View Post
hey Travis, I just caught up with your other thread late yesterday...
Sorry you are going through this and wish there was something I could do.

Mike J gave some great advice along the way.
Covered the possibilities pretty well, short of being there to see/test in person

I wish I were there! I really enjoy solving problems and this is certainly a good one.
As others have said, it will be something odd/silly in the end.

Yes, I cannot thank all of you guys enough! This place has been an invaluable source of information and help. I am both irritated and curious what this problem is..


Originally Posted by TheOtherEric View Post
Are you certain the DME is getting a good RPM signal from the flywheel sensor? The workshop manual gives a test procedure that IIRC you can do using just a volt-ohm meter. Definitely worth checking. For that matter, you should also do every other test there that doesn't require an o-scope. I did the RPM sensor test, and I recall the voltage was a little off from what the manual said to expect, but the test proved its point.

And try to restrain yourself from checking/replacing things you haven't messed with. E.g. it's highly unlikely that your DME would just suddenly fail. Focus on the things you've monkeyed with. You'll get through it.

The tach sometimes jumps a bit as I am cranking it, so it's getting some sort of signal. I don't have the workshop manuals though..


Originally Posted by Juha G View Post
Is everything stock (ECU, ignition, intake etc.)?

If your timing is right, you get spark and fuel you should be able to start the engine, unless the maps are wrong. But since it is stock ECU, that can be ruled out.
Check the intake air temperature sensor. If it is not connected (or broken) your ECU will think it is -40dgr celcius outside and will spray too much fuel and the engine will not start. This has happened to me before.
Is your MAF in working order?

It might be chipped. There's some conflicting information between the previous owner and the shop that maintained it; PO says the aftermarket chip went bad, and the shop says the DME itself is what went. I haven't looked inside to see what's what, but I am leaning towards the shop's story (that, and the receipt for ~$1600 worth of DME replacement!).

IAT is connected. I'm told it should start even if the MAF is bad..wouldn't run well, but it would run. I've tried starting it with the MAF connected and disconnected..


Originally Posted by Juha G View Post
If the timing was off a little, I think the mixture would ignite but just at the wrong time. You would clearly hear that, which is not the case (at least on the video)
BUT if the timing was off 180-degrees, you'd just push the unignited mixture out of the cylinders into the exhaust and it would not ignite at all... just a thought

Edit: And I say, don't call the Hook! Finish what you started. It will not only pump up your ego (as you didn't give up) but you will most probably also learn something new about these engines.

Yes, I agree, it seems like it HAS to be timing related...but I've checked and re-checked so many times, if there is something wrong I am just not seeing it. I found some pictures from before the tear down and at least for cylinders 1-3, the plug routing matches what I have now. Half the engine should run at least!

As much as I'd like to stick with it, it's my only car..and at $250/wk, this rental car thing isn't precisely cheap. Need to cut my losses at some point.


Originally Posted by TheOtherEric View Post
And as for the vacuum leak idea, you can stop by Home Depot and get some pvc pipe & rubber parts. And get a tire inflator valve from pep boys. Remove airbox, install your big cap, pressurize, and listen for leaks. Once you pressurize, it'll take several seconds for all the air to escape. If it can't hold any pressure you'll know you have a problem.

I've got something like this in mind, if I can find my freaking vacuum pump..


Originally Posted by axl911 View Post
+993 on this. You should get a very small AC voltage when cranking from the flywheel reference sensor. It's easy to check at the DME conector...or even easier at the connector tree on the engine.

Did you set the gap to 1mm between the sensor and the flywheel?

Gap was .80mm, spec is 1.0mm +/- .2mm. I'm tempted to try resetting it out to 1.0mm, but I will have to check for the voltage. That's one thing I've been wanting to test but wasn't sure what to look for with a multimeter..


Originally Posted by tonypai View Post
A couple of random thoughts....

1. Is there gas in the tank? Fuel pump working?
2. Is everything properly grounded?
3. Did you disconnect the battery? That dumps the memory on the ECU. When I did my LWF swap, the car ran like crap until the ECU re-learned everything. I had to crank it for a while and then the idle was really, really low until I warmed up the engine by driving it around for a bit.

Good luck.

Yes, I've got a half tank of gas, and with the DME jumper in place the fuel pump is audible. When I checked to make sure the injectors sprayed, I tried it both with the jumper and a relay, the guy helping me said the spray looked the same for both.

I have checked the grounds at the engine harness, starter and at the battery, everything checks out. I did have the battery disconnected, but we're talking probably several minutes of cumulative cranking time here..
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Old 01-11-2012, 01:37 PM
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Travis, the flywheel looks normal... sorry.

I was wondering if the sensor might have been bumped at some point (after you checked it) but I think Mike already asked about that.
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