1996 Collector Edition Corvette

[MostMint]

I can hear the injectors clicking alright, but not particularly through the intake. I'll get the videos uploaded somewhere when I have a chance.

[wxo]

No need to bother with the video. I'm hoping to do a startup test this afternoon. I will report what I find.

[wxo]

Nothing to find! Another disappointing day. I was ready for some forward progress, but it was not meant to be. Silvia would not start! Starter spins, got fuel pressure, no codes thrown, spark coming out of the coil, but no success. I'll get the shop manual out and follow the diagnostic charts to see what I can find.

[Maverick]

Is there some way, short of an oscilloscope, to assess the strength of the spark? In the beginning, it offered to start then would fire weakly on one cyl sometimes. Made me think maybe the spark wasn't what it should be.

[Basement Paul]

I would go back to what I touched since last time it ran. Mostly focusing near the Optispark IMO. Has to be something simple like a loose wire, ground, or something not snapped on all the way.

-BP

[wxo]

Unfortunately, I touched the timing chain and and sprockets and everything that's layered on top of that that makes it run. The last time I took it apart, it ran even with dirty connectors, but I got codes to identify the ones to check and correct. Of course I'm suspicious of the Opti-Spark especially with a good healthy spark out of the coil. Also, I'd like to check and verify the cam timing. Even though I believe I got the chain and sprockets installed correctly, (since it's my third time in there) there's always a chance I flubbed something. I need to figure out how to check this timing without pulling things apart again. The LT1's/LT4's don't have a balancer mark and timing tab where you can use a timing light. There must be some way to do it, but that's where I need to dive into the Service Manual. There's more learning to do in Silvia's school of the LT4.

[wxo]

Well, Silvia moved out of the garage today under her own power. It surely feels good to say that.
The noise that I've been chasing for 6 months turns out to be normal sound of injectors funneled out of the intake. The "crank no-start" issue was my fault. I had installed the timing chain wrong. The other gear noise I mentioned was a defective timing set from Cloyes. Once I put the old timing set back on, the gear noise disappeared. Inspecting the gear teeth on the Cloyes camshaft sprocket which drives the water pump shaft, I can see that the wear pattern is visible only half way across each tooth, hence the whining. I am in the process of negotiating with Summit Race for a refund.

The only thing left now is a P00336 Crank position sensor problem. I've been monkeying with the connector for a while to eliminate the problem, but it has just now reared it's ugly head again. I have a new connector coming tomorrow. If that doesn't fix it, I'll get a new sensor.

[MostMint]

Good news.

I was quite surprised how loud the injectors are on mine with the ticking.

[wxo]

I decided to replace the CKP sensor first, then do the connector if needed. I have an ACDelco branded one coming tomorrow from Amazon. Again, nothing is ever easy with this car. I had to jack up the engine to be able to get enough space for my hand down near the sensor. The old one is out now and it is some off-brand Chinese thing. This is not to say that the ACDelco crank position sensor will be any better, but it might be. Now I wonder if the bogging issue I've been covering up with higher fuel pressure may be caused by this wonky sensor. Wishful thinking?? We can always hope.

[wxo]

Got the new crank sensor installed on Saturday. I had to jack up the engine to get it out. It appears to have eliminated the P00336 related to the crank sensor, but had no effect on the bog/hesitation. I also installed a new/better fuel pressure gauge so that I can more accurately adjust the fuel pressure.

[wxo]

I put a new MAP sensor in her yesterday in hopes of solving this hesitation/bog, but, no joy. I still had to set the fuel pressure to 60psi to get it to run mostly without bogging, but it's still not all the way to the point where I think it should be in responding to the accelerator. My next move is to attach my AFR gauge to get a better understanding of what's going on.

[Maverick]

This has to be a mystery for the records. You're going to feel SOOOO good when you solve it.

[wxo]

Yes, but in the mean time it's drivable and fun as long as I'm careful not to stall it like I did this morning with a car right behind me on an up-slope at a stop sign.

[wxo]

Hooking up the AFR gauge may not work unless I install another bung and that, like everything else, could be difficult. I was thinking I could remove one of the H2O sensors and replace it with the wide band sensor, but I don't know if that will allow the engine to run normally on one H2O sensor and at the same time record accurate AFR info. The answer might be PCM dependent.

[Basement Paul]

Since it's a '96, and thus OBD2, if you have the right scanner, I'm thinking it already knows the air fuel stats and should tell you while the car is running.

-BP