1996 Collector Edition Corvette

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Maverick
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Re: 1996 Collector Edition Corvette

Post by Maverick »

Ah, the pleasure of doing it yourself and knowing it would never be done as well by a hired mechanic. Great work!!
Maverick
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MostMint
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Re: 1996 Collector Edition Corvette

Post by MostMint »

the injectors that came out of my C4 had rust stacked up on the fuel supply side. Once they dried out I tapped them on the bench and the rust came out like salt out of a salt shaker.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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wxo
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Re: 1996 Collector Edition Corvette

Post by wxo »

MostMint wrote:the injectors that came out of my C4 had rust stacked up on the fuel supply side. Once they dried out I tapped them on the bench and the rust came out like salt out of a salt shaker.
Were they usable after that?
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MostMint
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Re: 1996 Collector Edition Corvette

Post by MostMint »

I never tried them. I was just thinking if you are using those old injectors for line testing you might be introducing some rust into the return lines.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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wxo
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Re: 1996 Collector Edition Corvette

Post by wxo »

Excellent point! By using the old injectors, I was thinking I could to avoid contaminating the new injectors during the flushing process. But, I wouldn't want to add contaminants from the injectors back into the clean return line.
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wxo
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Re: 1996 Collector Edition Corvette

Post by wxo »

Yesterday was another tangible step toward startup. I cleaned out the fuel tank one last time and installed the fuel pump hanger assembly. I left the fuel return line unattached and added an extension to an external container to allow a flush of clean fuel through the system. This is to prevent any remaining contaminants from going back into the tank.
IMG_3655.JPG
Finally, I added a couple of gallons of fuel.

Next I turned my attention to the fuel rail. As I began to install the new Accel injectors, I noticed a difference in the clip location between the Accels and the originals.
IMG_3652.JPG
Not sure how to proceed, I emailed my injection specialist friend, Rich Jensen, for guidance.
Rich said:
Here are four different injectors that have been commonly used on the TPI and LT1/4 engines. 
The one on the far left is the TPI injector from 1988. The second is the LT1/4 style, the third is an Accel and the forth is a Bosch 24lb/hr. injector.  You can see there is a slight difference in the clip position but they all will work.
DSC09152 smaller.jpg
I think I should be able to get enough done today to attempt a startup. With this being an OBD2 car, I wonder how all the necessary sensors survived the three years in storage. Stay tuned...
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wxo
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Re: 1996 Collector Edition Corvette

Post by wxo »

Today I cleaned the intake bores for the injectors, set the assembled fuel rail in place and bolted it all down.
IMG_3659.JPG
The fuel system is finished. I was ready to pump some fuel through the system according to plan, but when I turned the key, the dash lit up, but I didn't hear the fuel pump run. I checked for fuel pressure at the schrader valve and there was none. I did no further troubleshooting. I hope this is some misunderstanding on my part on how this should work. I don't even want to think about a new fuel pump that doesn't work.

I'm not happy about how that went down, but I went ahead and worked on some other stuff. I was going to change the serpentine belt, but when I took a close look at it and the pulleys, I decided to wait until this thing is running. I reasoned that it would be better to let the old belt clean off the pulleys while it's running. I may have to take further action to clean them manually. I don't look forward to that.
IMG_3660.JPG
I also removed the intake ducting so that I could check out the MAF sensor. It looked clean but the throttle body did not. It was really cruddy, so I proceeded to get the blades and barrels back into good running condition again.

All that's left is the fuel system flush (if I can figure out how to get the fuel pump to run) followed by the first startup attempt.
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MostMint
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Re: 1996 Collector Edition Corvette

Post by MostMint »

the fuel system has no way of knowing the pressure in the system, the pump only runs for a couple seconds when you put the key in the run position (about 90% sure of this).

So here are a couple options:

1) get someone to turn the key to on while you are standing in the back listening for the pump to cycle - if you hear it you know it has power and should be good. From there you can crank it over for 30 seconds. If there is no power check the fuse first - who knows if that water froze up the old pump and when power was put to it maybe the fuse went. Also check the power wire at the plug with a meter or test light.

2) on the 89 I can make the fuel pump run by putting power to one of the contact points in the diagnostic port. I got this info from the service manual. Since yours is OBD2 the port is different but maybe you can find it on the internet somewhere or get a factory service manual

3) wire up something to put power to the pump directly from the plug
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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wxo
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It runs...sorta...

Post by wxo »

Andy, after exhausting several options, I went to option 3. I ran a jumper to the fuel pump from my truck's battery and the fuel pump took off. It did some squealing at first, but that went away after a while.
Now that fuel was flowing out of the return hose, I let it run for a short time and shut it off to check the bucket. A good amount of debris had come out of the system. I repeated this two more times and each time the debris was less. The third time, I saw a few specks of dirt and called it done. I was very pleased to know that the new fuel pump works.

This success now prodded me on to try a startup. After snapping on the injector connectors and hooking up the return line I hopped in and turned the key. https://youtu.be/mcL572Tn83k For some reason the VATS security decided to stop me from stealing it, so I went away to calm down and think. Knowing that it takes about 4 minutes to reset itself, I came back later and it let me in. I'm not sure what to make of it. I'll think about it some other time.

It appeared to me that the Vette always tried to start, but then shut down right away. I had seen this symptom discussed in the startup troubleshooting document. It pointed directly to the oil pressure sensor/fuel pump switch. So I jumpered the fuel pump terminals in the connector of the oil pressure sensor and, BAM, the fuel pump started again. Since the pump was already running, I decided to try to start it again. It started right up, but there was a load knock from deep in the engine, pulleys were squealing and smoke was coming up from places where I had applied penetrating oil. I let it run for a while and the knocking gradually got less and less, but it was still there when I decided to shut it down. During the run, I tried to feed it some gas pedal, but it would stumble each time. The old serpentine belt cleaned off a significant amount of rust from the pulleys. I think I'll leave the old belt on there for a while or until it gives up and breaks. I also checked for Trouble Codes and there were none. So that was it for today. I came in and ordered a new oil pressure switch from Ecklers Corvettes.
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MostMint
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Re: 1996 Collector Edition Corvette

Post by MostMint »

The VATS is a pain in the neck. You will have to read up on how to fix if you choose to keep it. There is a module you can buy that (as I recall) can replicate the signal from the VATS and send it to the ECU - this is what we use.

We didn't have the chip in the key so before we discovered this nifty little bypass module we had to figure out the resistance (one of 16) and used a rheostat to replicate that for the first start up. Kurt did the sleuthing looking up the resistances and setting the rheostat and repeat until you find the right one.

Glad to hear it fired up. I've had trouble with lifters sticking on cars that sit for a long time. Once you get on top of the other problems and it runs decent you can let it warm up and see if that helps.

As far as the inability to take fuel this is probably due to the MAF being dirty, or maybe the throttle position sensor. If it's like my car it will run without the MAF so you can at least unplug it and see if that changes anything.

Also there were problems with the Optispark ignition though yours is second gen of that so maybe they were fixed by then?
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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MostMint
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Re: 1996 Collector Edition Corvette

Post by MostMint »

Also,

I had some nasty problems with the car idling but would stall out when you tried to give it gas. Mine turned out to be low fuel pressure caused by a bad ground. I had removed a ground wire on the B pillar for cage fabrication and forgot about it. Pump would run but not make enough pressure. So maybe you have some kind of issue with fuel pressure.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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wxo
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Re: 1996 Collector Edition Corvette

Post by wxo »

My VATS key has been working fine until today. Assuming the VATS security system was working well, a couple of weeks ago, I measured the resistance across the key and ordered a blank from eBay so that I would have a spare key. It arrived today. I hope today's incident was just a glitch.

The I don't think the problem is a dirty Mass Airflow sensor. I looked at it yesterday and it was pretty clean. Just for good measure I sprayed some MAF cleaner into it. The problem may be spark plug wires. I have been ignoring them hoping it wouldn't come back to bite me. If the roughness doesn't smooth out, I may have to tackle them next.

You are right about the opti-spark. GM has corrected their cooling problem in the later years. I think I should be OK there.

I will probably not run the engine much until I get the oil pressure switch from Ecklers. It might be a week or so until I get it.
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GMJohnny
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Re: 1996 Collector Edition Corvette

Post by GMJohnny »

As I read about your VATS issue, I’m reminded of my 97 LeSabre that had an issue with it. The
solution was to wire a resistor in a wire under the dash that perpetually gave the car the resistance
it wanted to start. The chip’s ability to contact in the tumbler was a non-factor after I did this modification.
My LT-1 station wagon had an issue with starting once. It would crank but not fire until you used
starting fluid. Then it would run fine. That issue turned out to be an oil pressure relay. I found it bizarre
that the car had this on it, but basically the relay would provide power while the oil pressure was low
at start up. Once the car was running and oil pressure was up, the relay wouldn’t be required.
I’m not certain either of these will help you, but I figured I’d chime in in case they helped. This
thread is more interesting than the evening news! Keep going!

GM
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wxo
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Re: 1996 Collector Edition Corvette

Post by wxo »

GM,
I would like to keep the VATS operational if possible. This is going to be a driver and I like the security concept as long it does not become a PITA.
We will see.

The oil pressure sensor in this car has a switch integrated into it. The switch completes the circuit to allow the fuel pump to run as long as the oil pressure is sufficient. When I tried to start the Vette, it would catch and immediately die. If you watch in the video and filter out all the horn honking and chaos, you will see that that's exactly what happened. When I attached a jumper across this switch to close the circuit, I was able to verify that the switch was not working correctly because the fuel pump started up immediately with the jumper attached. This kept the fuel pump running to allow the engine to start.

I'm buying so many parts for this thing, by the time Carlisle comes around, I won't have anything to buy. The latest thing to arrive at my house was this
IMG_3671.JPG
For the console. I just couldn't resist. I know this crowd would understand. :mrgreen:
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wxo
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The rise and fall

Post by wxo »

When I got up this morning, I just couldn't resist going out to the garage and starting her up one more time. Before I did, though, I looked all around for a vacuum leak and I found a big one. It was a major hose in the EGR system which I had forgotten to connect after I worked on the spark plugs.
So I put my jumper on the oil pressure sensor to get the fuel pump going and hit the key. She started right up, but the knocking was still there although greatly diminished. Once at operating temp, here's the videos. Be sure to watch them back to back to get the full effect. https://youtu.be/fOvdAW_BsUE.
Then, to quote Paul Harvey, "here's the rest of the story": https://youtu.be/Vbck-kV2ToU
IMG_3678.JPG
New heater hoses are on the way. The anti-freeze that ran out looked like it had been in there for decades. I plan to install the new heater hoses and possibly perform some kind of flushing process before installing fresh radiator hoses and filling with Dex-Cool. A new thermostat probably wouldn't hurt either.
As an aside, here's a tip on how to stop a pesky leak from the AC low side port:
IMG_3680.JPG
I've never seen this done before.
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