1999 sl2 no start-now

[mhorning]

Daughter has a 1999 SL2 that started dying, the only code was for the EGR (valve and low flow, as I remember) took it off and cleaned it and ended up replacing it. After a couple of days it when stated it would rev to 2k RPM or so and then fall back, idle real rough and eventually die. IT would die at stoplights unless she rode the gas to keep idle high. She drove it the other day and when she went back to it it would not start. It has fuel pressure and spark- what the (&*%!? I have changed the CPS (what a pain that was, why in the name of Zeus's butthole did they put it underneath and behind the starter) and have tried WOT as well as pulling plugs to make sure it wasn't just a flooding issue. The ECTS has been changed about 3 months ago (although I'm not sure that would cause a no start). I have cleaned the intake and shot starting fluid in there and it still won't start, although it almost feels like it tries to fire one in awhile. I can smell the ether and unburned gas so I'm sure itthe manifold is clear and the injectors are pulsing (will veriy with a meter) . What the heck else could this be? The PCM? Even so I would think that if I had fuel and spark I'd at least feel it kicking while turning over and try to run? I'm at such a loss

[fdryer]

If you tried starting fluid and fuel isn't an issue, intermittent spark may be the problem. A spark test is needed. Simply removing and cleaning the coils and ignition control module may restore full spark.

[mhorning]

Also already did that. Was concerned weak spark was the issue. Cleaned both and has tested the ICM and both coil packs tested good.

[billr]

Trying the starting-fluid is a useful test, but if the engine won't start that way you have to repeat the test after disabling fuel. If the engine is flooded, starting fluid may not help. (Holding WOT may not prevent flooding) Pull the plugs. let the cylinders and plugs air-out, then retry starting it with starting-fluid after pulling fuses/relays for the pump and injectors. While the plugs are out, check compression. It's nice to know the basic engine is OK, and cranking for the compression test will help to "air-out" the cylinders.

[mhorning]

I have had the plugs out and cranked it with the fuses pulled for the fuel pump and injectors. I cranked it 20 seconds on 3 minutes off about 15 times. Put a shot of ether in each plug hole and put new NGK plugs in (I had cleaned the old ones, but for $3@ I thought it was worth the try). After replacing plugs I cranked and It would fire and back fire intermittently with the WOT. If I let the throttle go to home it won't even fire, so it acts like it's flooded but after all of the cranking I would think that would have cleared. I pulled the plugs and they weren't wet so they shouldn't be shorting. The only think I can think of a this point is that somehow something is blocking the intake. I forgot to mention the firing and back firing occurred with the EGR valve pulled so I could see what (if anything) was hitting the exhaust. I would have thought with spark and a shot of starting fluid that it would fire at least a couple of times each cylinder but it doesn't, it's quite irractic. I gave a bad tank of gas a thought but with the ether in the intake even if it was not the best it still should have fired. God, I miss the days of an engine running with spark/compression/fuel and not a bunch of computer controlled crap. I keep wondering bout the PCM- anything that it might do that would allow spark but the cylinder not to fire? The revving and dying- are they related to this or just a coincidence and not a precursor to the no start?

[billr]

Did you take compression readings? Where does it seem to back-fire, out the exhaust or out the intake manifold? You might try the starting-fluid again, but spraying into the intake just before cranking, not into the plug holes before installing plugs (normal fueling still disabled). Have you checked the timing chain, for tightness at least?

[mhorning]

I'll have to go to Autozone and borrow a compression tester. I did find that I had somehow gotten the firing order screwed up and had 2 of them reversed, so that took care of the backfiring (it was doing both exhaust and intake) but still only wants to fire one or two cylinders for every 20 seconds of cranking. Compression is probably ok on 2 of the cylinders based on me stupidly leaving the plugs on top of the heads (because they are such a pain to get out if your sockets doesn't hold them tight enough to pull them up and out) and I launched 2 of them out of head and across yard with the compression. I haven't checked the chain- I'm not even sure where it's at on this one. Doesn't take too log of working on this to miss my truck and all of the room in the engine compartment.

While cranking at one point I had a big wad of black ooze come out of the EGR valve hole. I can't tell if it is oil or petro based so I'll have to do the comp test to rule out a ring having given up and the blow by dampening the firing of the cylinder. I would expect that the others would fire though, even in that situation. I'm thinking there is still something in the intake, I know she cranked it until the battery was dead so if she did have some watery gas in it she may have loaded the thing down so much that is still hasn't dried out enough (it's been a week).

I took a hair dryer and put in in the opening of the intake with it held at WOT and cranked it several times hoping to hurry the drying out along and that seemed to cause it try to fire more ofter so I'm thinking it's still in a flooded condition (flooded with what I don't know). Would spraying intake cleaner or ether into the intake hurry that along or make it worse at this point? I need to get it running and get my daughter back in it before she gets too attached to my truck and I never see it again.

[fdryer]

1-When you leave the egr valve off, you're allowing more air into the intake manifold so this would either work immediately for a normal engine (revving to rpm limits) or create more problems as you're having. Leave the egr valve connected or make a temporary blocking gasket with the valve holding the gasket in place. Allowing the intake port of the egr valve to pull in fresh air simply leans out whatever fuel/air mixture is being injected.

2-When flooding is suspected at any time, removing spark plugs are the first thing to do to see evidence of flooding; soaked or wet plugs. Did you see this or not? Only a few starting attempts without the engine firing up and removing plugs is more than sufficient to show wet or dry plugs.

Wet plugs dry off quickly. Flooded engines dry out by simply using the starter (with plugs removed) to run the engine as excess fuel is blown out each cylinder is one or two short bursts of starter operation. With no compression, engines spin up quickly. A spark test can be done at this time to verify spark before putting plugs back into the engine. With the engine free of excess fuel, a start should occur. If not, hold pedal to the floor on subsequent starts. This presumes flooding is still occurring otherwise a no fuel issue, leaned out mixture or spark should be considered.

If a lean condition is found, no flooding occurring, the coolant sensor may be faulty. The majority of coolant sensor failures occur with rich or flooding mixtures. A few have failed by running leaned fuel mixtures with backfiring into the intake manifold and flames coming out the throttle body. Replacing a faulty coolant sensor corrects these two conditions.

[mhorning]

So I took Billr's advice and pulled the valve cover to check the chain tightness and lo and behold the Cam gears are pretty shot. I wouldn't have guessed that it was a timing issue on one with less than 150K. What's the normal life of the timing components? Daughter swears she never ran it low on oil, though don't know about before I bought it. I probably wouldn't have thought to check those either, but when I pulled the cover I was inspecting the valves for a stuck valve and noticed that the intake and exhaust on cyl 3 valves were both open at the same time- not good. I gave the engine a crank and the spot the exhaust was in the chain just slipped around the gears. So now the question is does she have a failing tensioner? I dread the thought of re-timing this thing just because of the lack of clearance between the front of the engine and the side of the vehicle. Can you do this without pulling the engine. If I were to assume (I know dangerous) that the gears on the Crankshaft and the chain were OK is is possible to set the timing without having to get to the crankshaft? If I could set TDC and replace those 2 cam gears to make sure it would still run OK that'd be better. Is there a clearance issue on this engine? Are we OK or is there a valve head sticking out of one of the pistons? The Exhaust cam is the one slipping, I assume that the intake is still close to being correct on the timing.

Thanks for all of the help-like I said I'd never have checked that, it just seemed like the way it was running and then wouldn't start that something electrical had failed. So now my question is: "Is it possible that this thing had jumped a single tooth and that was what was causing it to die and idle erratically and then it finally gave up and lost timing as she was starting it?

[cdxhizors]

Originally Posted by mhorning

So I took Billr's advice and pulled the valve cover to check the chain tightness and lo and behold the Cam gears are pretty shot. I wouldn't have guessed that it was a timing issue on one with less than 150K. What's the normal life of the timing components? Daughter swears she never ran it low on oil, though don't know about before I bought it. I probably wouldn't have thought to check those either, but when I pulled the cover I was inspecting the valves for a stuck valve and noticed that the intake and exhaust on cyl 3 valves were both open at the same time- not good. I gave the engine a crank and the spot the exhaust was in the chain just slipped around the gears. So now the question is does she have a failing tensioner? I dread the thought of re-timing this thing just because of the lack of clearance between the front of the engine and the side of the vehicle. Can you do this without pulling the engine. If I were to assume (I know dangerous) that the gears on the Crankshaft and the chain were OK is is possible to set the timing without having to get to the crankshaft? If I could set TDC and replace those 2 cam gears to make sure it would still run OK that'd be better. Is there a clearance issue on this engine? Are we OK or is there a valve head sticking out of one of the pistons? The Exhaust cam is the one slipping, I assume that the intake is still close to being correct on the timing.

Thanks for all of the help-like I said I'd never have checked that, it just seemed like the way it was running and then wouldn't start that something electrical had failed. So now my question is: "Is it possible that this thing had jumped a single tooth and that was what was causing it to die and idle erratically and then it finally gave up and lost timing as she was starting it?

Changing it in the car is doable..hard part is getting the cover back on without smearing the rtv(since there is no gasket you use rtv all over the cover) raising the motor and lowering it helps to wiggle stuff free and get to bolts.

[mhorning]

So what are my chances that there was no damage done? The point at which it failed was 180* from intake and being that far out there is a chance that something made contact. Is there someway to see if there is a bent valve without pulling the head?

[Steve44]

Something like this could be useful:

http://www.amazon.com/gp/product/B00...E7FQ4WCQVVJCAF

[mhorning]

Originally Posted by Steve44

Something like this could be useful:

I acually have inspection camera (I'm a telecommunications field engineer, though not a mechanic) and hadn't thought of that. Can you see the valves if you use one of these on this engine. I've never tried that and wasn't sure you could get it focused on the valve area.

[mhorning]

So I fixed the timing issue and now it will start and run, however it won't idle and when you throttle up it surges like the it's cutting out like the key switch is being turned on and off rapidly. Still no codes so I'm not sure where to go from here.

[fdryer]

Run a compression test as this can tell you a lot more than guessing if valves were bent from missed timing. Good compression counts on both valves closing and sealing with piston rings providing the other seal. Burned exhaust valves or damaged valves from mistiming will simply show compression well below 100 psi. Good compression, 180 psi. Most engines are interference type - pistons and valves overlap and precisely synchronized like gears to never hit it each other unless mechanical mistiming occurs...........

[mhorning]

I ran a compression test and the results were well above 100~ They were 165, 180, 185, 190.

The idle and rev problem started before it "died" so I don't know if it is related to any of the other problems or not. I think I'll try blocking the EGR valve and see if that makes a difference. As I said the only codes I ever got were for EGR valve and EGR low flow. I cleaned the EGR twice and then ended up replacing it with one from a none yard (which the 1st one I got was also bad) so it could still be bad, but not setting a code. I cleaned the EGR ports and valve with brake cleaner as recommended by the guy at O'Reilly's. Any other suggestions?

Oh I pulled the head because I figured I'd have a bent valve at the least (or worse given my luck) and astonishinly becuae the gear on the exaust cam failed with ALL valves closed none of them ever made contact with a piston. If the gear had slipped even just a couple of teeth and made another revolution I suspect I would have had a bent valve or a piston with a hole in it.