Hello fellas! It's been a while.

My buddy just picked up a non-running procharged LT1. Being that it is not my car, I will try to give as much info as I can. It's currently in a regular service shop off to the side, and the guys there are screwing with it when they get the time. When my friend bought the car, it would crank for days but would not fire. The guys in the shop immediately pulled all the procharger ducting out, took out the water pump, and changed the optispark module. They reported that the vehicle "shot flames out of the throttle body when we tried to start it afterwards." They pulled a plug, and said it was black and covered in gas. They also said that the vehicle "had weak spark, not enough to start the car."

Unfortunately my friend didn't just bring the car home so we could check everything from step 1 instead of ripping everything off the car and jumping into the middle. I have no idea if the car has fuel pressure, if the injectors are pulsing, if the ignition coil module is good, if the harnesses are getting the correct power, or even if the cam dowel pin was installed correctly into the opti spark. We plan on going over all of this tomorrow, and seeing if the computer stored any codes. Also worth noting, the secondary fuel pump for the procharger has been disconnected during all of this.

EDIT: also worth noting, I just realized when the shop ordered a new optispark, they received a vented one. This car is a 93, would a newer vented-style opti even work? The car previously had an MSD distributor on it, which I'm pretty sure comes with a different harness.

So, as far as the mechanics say:

• Dumping fuel/fouled plugs
• Shooting flames out of TB
• New opti unit
• Weak spark

If anyone has any input that would be much appreciated, as I have never owned an LT1 vehicle.

Thanks!

 

If you don't have it, go back to the repair shop and retrieve the MSD opti, it's one of the better units still available and MSD has a rebuild service for it. A vented opti won't work on a '93 unless it was converted to the later timing cover and longer camshaft dowel pin. To avoid pumping too much fuel into the engine while troubleshooting the ignition maybe pull the fuse on the fuel pump. Check for spark with a timing light on one of the plug wires without pulling the spark plug, this way you'll check the ignition energy under the load of cylinder pressure. With a weak coil it'll give a spark to a plug outside the cylinder but won't have enough energy to jump the gap under cyl pressure. Once you get the ign straightened out then add fuel and change the fuel contaminated oil.

 

What brand opti did you replace the MSD with? ^Like he said MSD will rebuild it for $137 tops....I had it done to a used one I bought that had a high RPM misfire, took about 3 weeks though. A new coil is cheap and quick to change out, I would avoid the MSD "blaster" coils though, I had one of those go bad.

 

Hey again fellas. Thanks for the replies. I saw last night that the MSD opti is adjustable, and has the screw on the top to adjust timing. When we went back this morning, it appeared that the old opti (the one I thought was an MSD) was just a factory style opti with an MSD cap. The cap was siliconed on. Red, MSD logo on it, and had the lower vent tube. Backside was that of a stock 93 spline driven opti.

Now for some updated info:

• Fuel pressure: Turning key to ON and engine OFF, the pressure was at 25 psi. Cranked the motor, and it shot up to 47 psi and held steady for the next 10 minutes until the shop manager popped the gauge off. I checked the vacuum line that runs from the fuel pressure regulator to the intake manifold, and it was bone dry. Injectors are "assumed" to be alright as the pressure did not slow bleed during those 10 minutes, but you know what they say when you assume. The mechanics said that the injector plugs were all pulsing correctly after installing the new opti, which they did not before.

• Spark: I was not present for this, but they said it has spark at the plug wire (plug side) as well as the coil, but like i said - I wasn't there to see it so I can't comment on how strong the spark looked. When I showed up today, they were replacing the plugs. They replaced all of them but the #5 and #6, because they said they could not get to them without removing the headers and just wanted to see if it would start.

• Compression: Unknown as they "couldn't get to the cylinders with the headers installed."

The new guy hooked up the plug wires, and they tried to start it. Nothing - as it cranked you were able to hear it pushing out air (almost like it was sneezing) on one of the cylinder strokes or something. It was also spraying oil out of the dipstick tube, the level was said to be normal. Turned out the guy hooked the wires up wrong, so they went through them again and redid them. Tried to fire it again, nothing changed - sounded exactly the same. This is all with oil that smells like gas, by the way. Next, we noticed on the scan tool that the coolant temp sensor was reading -30* , so we found that the wiring was a bit loose. With the temp sensor unplugged, and holding the wiring so it would show 82* (room temp) they tried to fire it again - still nothing. This was the sensor that plugs into the water pump. I also noticed that the sensor that is in the drivers side cylinder head was unplugged too. Not sure if that one is needed for the car to run. The only other abnormal reading on the scan tool was the oil temp, which showed in the negatives as well. Lastly, I hopped in and pressed the pedal to the floor, as I've read that will cut the fuel supply on startup. I turned the key, and it cranked without making the "sneezing" sound, but they said it shot a flame out of the throttle body.

As it is not my shop, I can't really tell anyone what to do. But they are leaving the car outside for the weekend, and my friend and I are going to dig into it a bit further ourselves.

Questions:

1. Is it possible to install a 93 opti incorrectly? (as far as lining it up goes, and screwing up timing)

2. The car was procharged and owned by a 20 year old. Could he have been beating the **** out of it and the timing chain jumped/stripped the gears?

3. Is there still fuel in the cylinders? They said the cylinders were full of fuel and the old plugs were fouled, so they simply removed the old plugs and put in new ones, continuously cranking the car trying to start it, while it's presumably dumping more fuel in. I'd say it was cranked over another 10 times today for at least 5-10 seconds each time.

4. How would I go about getting the rest of the fuel out of the cylinders?

5. Is it possible that the current coil is on it's way out and isn't strong enough to start the car, but still shows spark at the plug wire?

6. Could the two old plugs that were left in be an issue?

I think that's it for now. I think my friend and I may take the water pump and balancer back off to check that the opti is installed correctly & cleanly. They left old wires stuck in there and crap because they were "stuck" and "just wanted to see if it would run."

Thanks again everyone, any help is much appreciated.

 

The spline drive opti can be indexed wrong during the install as the master spline is very small and can be forced into the wrong spline by knuckleheads. As to the oil spraying out the dipstick tube, this could be from the level being way too high from fuel dilution or the stock Hyper pistons could be ruined from the boost. Stock shortblocks don't live under boost for long.
You might want to do a compression test to see what condition the cylinders are in. If th compression is extremely low the engine won't start.

 

Thank you for the quick reply. We're going to go grab some fresh oil now and see how much drains out. What do you think my next move should be? Pull the opti and check that it's lined up right, or pull off the headers and do a compression test? No idea how it is to take headers off an LT1. Maybe I can just unbolt them and stuff them down out of the way.

By the way, the opti unit they put in is a "Cardone."

 

Change the oil. Maybe check the compression on #1 since it's easy and any other cyl you can get at without pulling the headers. To check the opti you'll have to pull the WP and balancer.

 

Is this thing tuned at all for the mods or just a basket case with no records of whats been done? Sounds like a nightmare trying to sort out all that on a 93 car with their unique PCM once it's been heavily modded like this....I hope you friend got a good deal! That 20 year old kid may have tried something shady and sold it with a known blown engine since LT1s generally don't last long on it stock.

 

Just got back home. When we showed up, the shop manager already took the water pump back off and bought a new opti (an additional unit) to rule out the first one he ordered being faulty. So at least I don't have to do that LOL. I pointed out the guide in the spline, and he installed the new opti and hooked up the plug wires. The old oil smelt horribly like gasoline, there was definitely more "oil" in there than there should have been. Once the new oil and filter were in, the car sounded TONS better while cranking. It slightly sputtered 3 or 4 times but still wouldn't turn over. The shop manager was watching the scan tool while cranking and said that the RPM value remained at 0 the entire time. At this point it was past closing time for them and they called it a day. Unfortunately I can't stay in their shop and keep playing, lol. I think one of them left something to hold the TB blades open overnight - I guess to dry out any remaining fuel.

I have no idea. This is the second time my friend has bought a vehicle from the 20 year old, and the kid had this Camaro running with the procharger for at least a year that I know of. There's videos of it running and you can distinctly hear the procharger. The car has 77k miles and he got it for less than half of what the procharger even costs.

Tomorrow is another day I suppose. I believe I heard the mechanics saying that the next step (for them) would be removing the timing cover and checking that everything is aligned properly. They should probably do a compression test first, but I'm also a young kid and they don't want to hear what I have to say.

 

Side question: does the rotor need to be positioned any particular way before putting the opti on? Or is that what the guide is for on the shaft?

 

LT1's were such a limited time run and so exclusive, no one but LT1 experts really, know how to work on them. I just recently had the exact same issue as your friend.. I had installed my opti wrong... Go ahead and find top dead center on cylinder #1, turn your cam dowel pin to where it's at 9 o'clock, install the opti, plug wires etc, and it should fire right up!

 

If this works, I'll have to send you some strippers.

How do I go about finding top dead center with the timing cover on? Also, how would I turn the cam if the balancer is off? Can I line up the opti into the shaft and just turn it that way?

Thanks a bunch!

 

^^^^What He said... Plus I will ask What Coils on it??? If its an MSD Blaster Throw it in the Trash & put an A/C Delco coil on it!!! My new rebuilt S10 I put in My S10 acted kinda like your sayin & I pulled the TR55s Everyone told Me to install & cross referenced the stock plugs & ended up grabbin R44LTS A/C Delco plugs & gapped those to .040 because the NGK TR5 plugs had the screw on caps & I dont want those on My ride!!! I also had a Stock Coil & put it on too Bam Fired right up!!! Put the MSD coil on & same ****!!! I threw it in the trash... It might work if I would install the 6AL box LoL But that box will be for the 396 Nitrous build Hope My Ramblin Helps a little...

 

I had my girlfriend bump the key to just hit the starter, while I had my finger on the spark plug hole on cylinder #1 till it blew it off the hole. There's other ways, this is the quickest. If the timing chain is correct then the cam dowel pin should already be at 9 o'clock. And there's a certain slot on the opti the dowel pin needs to go inside, trust me I've made this mistake.

I went ahead and fired the motor up for like half a second just to see if it would even fire. Don't do this much or over a few seconds, as there's no water pump on.
After all this, just take your time. Make sure all your plug wires are routed correctly, take your time installing gaskets.. Last thing you'd wanna do after all this is see a drip coming from the waterpump jackets.
PM me if you need any help
EDIT: sorry forgot this was a 93.... Ignore the picture

 

The coil looks factory or a factory replacement.

In other news.. *drum roll* My friend just messaged me, the mechanic said the timing marks under the cover were completely off. We're gonna head over in a few!

Again, thank you guys.

 

So, I walk in the shop, and the mechanic said "The timing was 180* off! it wasn't even close. We just put it in the right spot." I look down, and see they have the dots lined up at 6 and 12 o'clock. So I look at him and say, "So you have cylinder 6 at TDC then?" He looked at me like I was crazy and replied, "No, number one is at TDC." I informed him that for the 6 and 12 o'clock positioning of the dots, #6 has to be TDC, and for 12 and 12 on the dots, it needs #1 at TDC. He pulled me inside and showed me the AllData shop manual, which shows them at 6 and 12, but does not state which cylinder is at TDC. After nearly everyone in the shop disagreeing with me, they googled it and said.. "We have to put it back to the way it was."

So, the timing was already correct to begin with. He said before he took the timing cover off he tried to start it again and was getting 10 degrees timing advance while cranking. My opinion, is that the plugs got fouled again during all the screwing around after they were put in. Monday they are going to switch the timing back, remove the headers and plugs, and go from there.

I'll leave my opinions to myself, as you never know who's reading.

That poor car.