This may be a long post. Mostly because I just want to be as detailed as possible. So if someone takes the time to read it. I truly appreciate you and your time. Oh, and I'm not the best at spelling or grammar. So please, no hating lol. About 6 months ago I bought a 1996 Camaro Z28 LT1. I've had 2 94 Z28 and a 85 with the small block 355. The 94s I bought, one was pretty much stock, and I didn't do much to it but tear it up. I was young. The other I got with a few mods already done to it. But never did much myself. The 85 was easy to work on. Just wanted something a little newer. The 96 Z28 was released when I was 12yo. From the first time I saw it I fell in love with the car. Always wanted one. Just never found the right circumstances. Well. I finally found one in good shape with lots of character I felt like. Nothing really done it it. New seats and rims. But no scratches or cracks or anything like that. I bought it from a small car lot out of 7 points texas. Drove it home with no issues. Shes not my daily driver. So I didn't drive her for a few more days. A couple of days later I drove her again. She had trouble cranking, missed horribly when driving. Ran for about 10 minutes and died. Wouldn't start until she cooled down for about 15 minutes. Then after that she still ran bad. I went and talked to the car lot. They seemed like stand up guys. So I listened when the recommended a repair shop in town. Took it there. The guys said it was my optispark, and I needed new rear shocks, 2 new tie rods, and bushings. I let him do the work. Picked her up. She drove better. But would still dies after about 10 to 15 minutes of driving. Then starts back up and doesn't die until I let it set for a couple of hours again. So this went on for a few weeks. Then one day she died a 2nd about 30 minutes after the first time it died. And wouldn't start back up. The car has 150000 miles on it. And the original fuel pump. A buddy told me to replace the pump. So I did. Car still wouldn't start. At the time I didn't know much about LT1 reverse flow motors. And I didn't trust anyone to work on it anymore. So I done a ton of research. Bout 300 hours worth to be honest. Started going threw my motor. Found out my ICM was bad and my coil had cracks in it. Replaced those. And it ran again for a few days. Then I noticed one day I had water running under it when I parked. Oh, and it was still dying after about 10 minutes only to restart and not do it again until it set for awhile. So I let her cool down and took her home. She didn't over heat on the way home. But I did figure out my temperature gauge wasn't showing the proper temp. When it got hot it never went above about half way on the gage. I flushed the radiator. And the water was horrible. So I started digging into the motor again. Found out the water pump was full of calcium or some kind of white build up. The blade on it was real wobbly. So I got a new water pump. Also a new thermastat, belt, starter, temp gage sensor, harmonic balancer, all of these OEM parts, and done a radiator flush. A buddy of mine that's worked on a few LT1s of his own helped me pull the optispark apart. And it still had moisture in it. But not in the eye area. He said with it being so new and the eye dry, to just clean it out, spray some silicone in it. And use it again. So I did all this. Put it back together. Oh, I also cleaned the throttle body and intake. The top chamber of the throttle body was horribly dirty! I started her. She drove good for about 15 minutes. Dies again. So I set there like I always did. Waited 10 minutes, wouldn't start, 20 minutes, wouldn't start, after about a hour of this I started checking for fuel and spark. I wasn't getting fuel. I jumped the fuel pump. And it had pressure at this point. So I tried starting her with the fuel pump jumped. Still no start. So I had a buddy take her back home. With this virus going on. Works been slow. I own my own small AC biz. So I started thinking I might as well rebuild the hole motor. There was a few oil leaks I had found i wanted to fix Anyway. So I have the motor all ready to be pulled now. Everything unhooked, I'll be pulling her out here in about 2 hours. My questions are, what parts should I replace or rebuild? And what brands? Or would a rebuild kit be my best option? If so what kind. I'm going to put some sort of long tube header on it, a cam most likely and exhaust, Which would be the best to go with? Price conscious options of course lol. Just in case my first LT1 build doesn't go well and until this virus stuff ends and work gets back to booming. Ot until it hits 90° here in Texas. People can't live without AC in Texas. And if I do these what sort of other parts should I buy with them? I haven't done a full engine rebuild in almost 10 years. So I don't want to miss anything. I have a buddy that going to help me put her back together. But hes more of a truck guy. And doesn't have much knowledge on LT1 proformance parts and so on. Also if I do get the rebuild kit. Should I get the top or the bottom end kits? Or both? Or should I buy the parts not in a kit. I know some of this is hard to answer without seeing what the inside of my motor looks like. But I'll have some pics of that up tonight or tomorrow sometime. Also, and this is huge for me. What's the dying after a few minutes all about? I've read through about 150 different forums and pretty much everyone says something different. From heats issues, to my MAF, to my passlock system ( which I have already bypassed by the way, Use a resistor and it worked great so far) and many more. Also when the car hits about 110 it starts to cut out. Not like a governor cut out. But a miss or something. It's a 6 speed manual transmission btw. I have already purchased a cold air intake, a oil level sensor ( my old one was leaking, and 10.5 mm proformance plug wires. I also have on my list to order transmission mount, tstat housing, pilot bearing, throttle body injection gasket, both coolant and vacuum hoses, spark plugs, timing chain kit, oil pan( the old one looks horrible), throttle body gasket kit, oil pump, AIR/smog check vavle, EGR vavle, rear main seal, going to test my injectors and replace as needed ( or would bigger injectors be better?), and most likely my fuel real. Is all this over kill yall think? If so what parts should I not buy, or if I do, what brands? I know if I seen someone asking all these questions I'd tell them to go to a shop and get it done. But in my experience you can't trust most of them guys, and everytime I use one it always backfires on me. I'd rather do it myself. and if it blows up. Least I learned quite a bit about my motor, and I can do it over again. That's the great thing about muscle cars lol. I've had a few people tell me to do a LS swap. Honestly, I've spent the past month watching 100s of hours of videos and 100s of hours reading about the LT1. I've bought the rebuild manuals, and so on. And dont want to learn the LS at the moment. Plus I want to keep her original for the most part? So this is where I stand. I'll post a few pics I've taken of her when I was tearing her down to do the water pump. Shes kinda dirty in the pictures. It was raining like crazy the week I done all this and I live on a country road. Oh also when I took the original water pump and so on off. I found out the shop I let do the optispark didn't put new water pump gaskets on it, or tell me about the oil leaks, or the broken bolts he broke that hold my water pump and AIR bracket on. And much to much to list really. So again any help would be greatly appreciated! And if you live in Texas, Oklahoma, or Arkansas I can hook you up with some AC or heating work sometime, im the only 5 star rated AC company in my area lol. Thanks for the read guys... and gals! Yall have a great day and stay safe out there!

 

Based on moderating this site for 20+ years, and recognizing the limited number of truly active/knowledgeable members here currently, I think you will get more responses if you break that single paragraph into smaller paragraphs, organized by subject. Numbering the paragraphs will allow people to respond to a specific subject without having to rely on quoting a specific portion of the above message.

 

Seems like the main problem is the stalling after running for 10-15 minutes. I see you have replaced many parts, but at any point did you do any diagnostic work like checking the fuel pressure and scanning for codes? Did you have the ICM tested before replacing it?

When the shop replaced the Opti, what brand is it? There are only a couple sources that are reliable. Most of them are cheap Chines rip-offs that can fail right out of the box. Is the “vent” system correctly hooked p to the Opti? That was added starting with the 1995’s and should help prevent moisture buildup.

Ditto with the fuel pump replacement - what brand? Again the market is flooded with crappy Chinese counterfeit copies of name brand pumps.

A lot of oil under the top cover of the throttle body can be the result of a clogged PCV valve - have you replaced the PCV valve? It can also be caused by excessive piston ring blowby, in excess of what the PCV system can handle. Pressure builds in the crankcase, and is relieved by the vapor reversing flow in the line that runs from the passenger side of the throttle body o the passenger side valve cover. The crankcase vapor,, loaded with entrained oil ends up on top of the throttle body, and drips down in front of the blades, ending up inside the intake manifold, and getting all the way to the combustion chambers.

When you replaced the thermostat, did you get one SPECIFICALLY for the LT1 engine? Most parts shops will give you one for an earlier SBC, and that's not correct. When working on the cooling system, have you always done the correct air bleed procedure to get the air out of the reverse flow system?

 

Thanks for the info! I'll start breaking my questions down more a little at a time. I was afraid it might be to long and folks lose interest. Sorry about the late response! I was in a horrible service area for a couple of days.

Yes sir, I had the fuel pressure checked, I bought me a code scanner and it's not throwing any codes. Or at least it wasn't when I replace the coil and icm. But a buddy of mine said something may be wrong with my PCM. So that's next on my list. I've been looking into the 411 pcm and doing away with the opti. I took the icm up to Auto zone. and they told me it was bad. So I bought a new one for 100 bucks. Only to fine the same 9ne for 20$ online! Lol

The optispark spark he got was a duralast gold from auto zone. It has a lifetime warranty it says But if it's cheap I'd rather purchase a better one. That duralast one was 160 tho. From what I've seen in diagrams. The optispark vents seem to have been right But both hoses were very loose. He should have replaced the hose also. I honestly don't know what kind of fuel pump was put in. A buddy done that while I was working out of town. I had never cut a hole for a pump before. and didn't want to tear up my car. I know he purchased it off Amazon.

I have not replaced the PCV vavle yet. But I will definitely add that to my list. When I got back home last night I went out and started taking the motor apart. The heads and bottom of my intake had about a inch of slug on it. It was horrible! So that makes since now. Thanks for the quick lesson on that. That's great info!

when I replaced the thermostat I got a 160° one. I told the guy to make sure it was for a reverse flow LT1 motor. he assured me it was. I pulled up some picks online of others And it looked the same. I think some had put the wrong one in before me. Because it was a little different from the one I took off of it. Yes sir, I did the air bleed procedure. It was honestly my first time doing it. so I watched a video on how to do it. Pretty sure I have it down.

The rest of the motor is all apart now to. Besides the lower end. Heads off and everything. My driver said head has the back bolt stuck in it. I can't get it off the head. I didn't even notice it was pulling the head off the block until Ihad it about a inch up. Hopefully i didn't bend it. I'm going to take it to a machine shop and get it checked tho.

I didn't notice the 2nd post was you also until I had replied to the first one. Thanks for all the info! I'll differently start breaking them down more. I'll try to upload some pics. My wifi and service is horrible when I live. So I didn't get to the other day. Have a great day! And thanks a bunch!!!

 

Shoebox website has a wealth of info on our cars:

4th Gen LT1 F-Body Tech Aids

Thermostat photos:

http://shbox.com/1/tstat.jpg

Useful book:


Useful article:

https://www.enginebuildermag.com/199...-lt1-engine-2/

 

Awesome! I'm on shoebox quite a bit. But haven't seen the other. I talked to my buddy and he said he just changed the motor on my pump. I just pulled it out and her didn't seal back the box around it. And it's a China one it looks like. Which is why I'm learning about all this myself. So I'm just going to order a new one. Also got on torqueheads website. Someone on FB suggested them and they have the delete kit for the optispark so I'm bout to order the kit from them and a new fuel pump and fuel module. Sorry to ask you so many questions. but do you have any suggestions for the fuel pump? Like what brand? And should I get the hole assembly? Thanks again!

 

The motor is the pump. Everything else is part of the “sending” unit. The plastic case (bucket) is critical to keeping the pump running. Interesting reading from Racetronix explaining why the bucket it critical.

https://www.racetronix.biz/product.asp?ic=fpa-003a

 

Thanks again for all your help. I read that article you sent me earlier explaining the difference between the parts and the years. You ever need any AC advice let me know.