Ok, little back-story - little over a week ago the car died on me at idle. Towed it home. Wouldn't start back up no mater what I did. I just replaced the plug wires and starter (been meaning to anyway - unrealated). Still won't fire up.
I'm thinking the opti is dead but whats worrying me is that when I try to start it - when I turn the key over it sounds like it just bearly wants to but then doesn't and then smoke belows out of the throttle body (I have a Clear LS1 style lid so it was very clear to see). Why the hell would it smoke out of the intake manifold? Is there something much more major going on inside the engine at this point than the opti?

 

Its probably just smoke from the gas...Did you scan for any codes?Check the ICM,Coil,are you getting full spark?If its Slow cranking charge up the battery.

 

Battery was on the charger before start up - had 12.8 volts when I tried. I'm going to test the coil and the ICM tonight using the sticky at the top of this forum. I'm hoping the smoke is just something simple like gas but what if it's not....

 

Scan it. Erratic signals from the optical cam position sensor could cause the engine to fire with an intake valve open. The cam position signals set trouble codes, but don't turn on the SES light.

Have you checked the fuel pressure? The Aeromotive LT1 AFPR's are know to fail frequently.

 

I have a cheap little scanner but it doesn't show any issues.

Funny you mention fuel pressure... I thought the thing sounded weird the last few weeks. Obviously the car won't start so I can't remember what the psi was at running or idle (had it set to 42) but when I turn the car to on engine off, it spikes to 35ish and drops to 0. It shouldn't drop to 0 should it?

 

Usually smoke backwards on an engine that does not fire indicates a flooding condition. The large amount of fuel doesn't ignite like it should and just billows out the intake. This is usually caused by a faulty ignition. At that point it's a good idea to replace cap, rotor, wires, plugs, coil and O2s.

If you want an idea of what I'm talking about, pull the cap off the opti and look at the contacts inside.

 

I swapped out the Aeromotive unit with a stock FPR and the fuel pressure seems to be acting better. Key on engine off it goes to 42psi and holds like it should. However - the car still won't fire. I'm going to take a break and wait for the heat of the day to cool off then go out there with my multimeter and test the signals to see if the problem is ignition (coil, ICM, opti, etc.) I'm not about to start buying a bunch of parts until I know whats the weak link.

 

your fp shouldn't drop to 0... pull the fuel rail and see if you have a leaking injector when you turn the key on. this may be causing the flooding

 

If you re-read what he posted, it only dropped to "0" on shutoff with the Aeromotive AFPR. With the stock FPR back in, it goes to "42psi and holds". Would appear he has already found the source of the fuel pressure loss on shutoff.

 

Yes, fuel presure is not the concern any longer. It's probably ignition realted. Probably going opti shopping soon. grrrrrr

That brings up an interesting question - where do you go to get a GM opti these days? I know most went threw that thepartsladi on ebay but she screwed everyone then disappeared (you should read her feedback - lots of angry people). I heard she changed her name to thepartspros or soemthing but thats not there anymore either... If this does happen to be an opti issue I don't want to drop 5 bills on an MSD unit that has only so so reviews. I also am not going to cheep out with one of those $150 ebay or CMS units either. Every "what opti should I get" post on here always points to one conculsion - OEM. So where is the best place to get them now?

 

If the problem was with the optical cam position sensor in the Opti, you would have codes present. If its a problem with the cap/rotor, like the rotor falling off, there are no codes. But you can check that out simply by pulling the cap. I'd check things out before assuming its the Opti and investing upwards of $400 in a new one. A faulty ICM would set a code. A parts store can test it for you. Simple to measure the resistance of the coil. Do some testing before spending money.

 

I'm going to. That sticky up top and shoebox's site are awsome when it comes to this. I'm not the type to waste money (Aeromotive FPR aside :-/ ) - just wanted to ask the question as a preimtive strike.