Please help me out here!
Drifting
Joined: May 2005
Posts: 1,629
Likes: 4
From: Somers CT
Did you get bit ? 
Pulling wires on an HEI is not a real good idea IMO because the HEI has enough power to jump inside the cap which can put a permanent carbon track on the inside of the cap. If you dont have an infra red heat gun try taking a crayon and touching the manifold at each exhaust outlet and watch the difference in the heat,or use whatever method you can think of (spit works also
). All your trying to do is find the cylinder that is not producing as much heat as the rest.
Pulling wires on an HEI is not a real good idea IMO because the HEI has enough power to jump inside the cap which can put a permanent carbon track on the inside of the cap. If you dont have an infra red heat gun try taking a crayon and touching the manifold at each exhaust outlet and watch the difference in the heat,or use whatever method you can think of (spit works also). All your trying to do is find the cylinder that is not producing as much heat as the rest.
Drifting
Joined: Feb 2005
Posts: 1,738
Likes: 2
From: San diego ca
Do this: Open your hood tonight after dark...start engine and look under hood and check if your spark plug wires are arcing....that may be the issue....(and you should replace the EGR in any case..)
BTW: Got your PM...great hearing from you....maybe we need another C3 clinic....remember this one...???
Just noticed you are now up in Winchester...otherwise I'd drop by and help you out....
Rich
BTW: Got your PM...great hearing from you....maybe we need another C3 clinic....remember this one...???
Just noticed you are now up in Winchester...otherwise I'd drop by and help you out....
Rich
1st thing I'd do is pull all the plugs, get a small cardboard box and punch 8 holes in the bottom with a screwdriver - label them 1-8 with odd on one side and even on the other.
Insert the plugs into their respective holes with the working end facing up, when you have the plugs in you can get a good idea of whats going on in your engine by closely examining your plugs.
Examine your plugs and then we can go from there.
A leaky EGR could give you a vacuum leak however egr shouldnt operate at idle anyway so thats not likely it. even less likely if youve replaced it and its still a problem
BTW your car uses a positive backpressure EGR which will not hold vaccuum if the car isnt running.A simple search for a replacement EGR shows that its a positive backpressure type.
The positive back pressure EGR valve can be identified by the letter "P" stamped next to the part number and date code. A back pressure valve is easy to spot because its pintle shaft is much thicker than the single diaphragm type. This is so because the shaft is hollow. The hollow design allows exhaust gases to flow into the shaft and push up on it. When positive back pressure in the exhaust system is sufficient, the shaft raises up and seals the built-in control valve. Once the control valve is closed, it allows applied vacuum to pull up on the diaphragm. Without back pressure to lift the hollow shaft and close the control valve opening, the EGR valve will not hold vacuum. It is bled off to the atmosphere. This design thus modulates EGR flow by modulating the applied vacuum. As engine load increases, so does engine back pressure, which causes the control valve inside the EGR to trap vacuum and open up. To test this valve, bring the engine up to 2,000 rpms to create back pressure, then apply vacuum. EGR should open and cause a 100 rpm drop or more.
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
Ha Ha, I think we saved your life that day Enrique, I seem to recall your brakes didnt work, or barely worked.
1st thing I'd do is pull all the plugs, get a small cardboard box and punch 8 holes in the bottom with a screwdriver - label them 1-8 with odd on one side and even on the other.
Insert the plugs into their respective holes with the working end facing up, when you have the plugs in you can get a good idea of whats going on in your engine by closely examining your plugs.
Examine your plugs and then we can go from there.
A leaky EGR could give you a vacuum leak however egr shouldnt operate at idle anyway so thats not likely it. even less likely if youve replaced it and its still a problemBTW your car uses a positive backpressure EGR which will not hold vaccuum if the car isnt running.
A simple search for a replacement EGR shows that its a positive backpressure type.
1st thing I'd do is pull all the plugs, get a small cardboard box and punch 8 holes in the bottom with a screwdriver - label them 1-8 with odd on one side and even on the other.
Insert the plugs into their respective holes with the working end facing up, when you have the plugs in you can get a good idea of whats going on in your engine by closely examining your plugs.
Examine your plugs and then we can go from there.
A leaky EGR could give you a vacuum leak however egr shouldnt operate at idle anyway so thats not likely it. even less likely if youve replaced it and its still a problem
BTW your car uses a positive backpressure EGR which will not hold vaccuum if the car isnt running.A simple search for a replacement EGR shows that its a positive backpressure type.
Here are the Video's from that day......
The u-joint...
The test drive..
Last edited by rihwoods; May 15, 2009 at 11:01 PM.
Thread Starter
Racer
Joined: Feb 2007
Posts: 290
Likes: 0
From: Winchester CA
Thanks a bunch guys! I will be looking into my hood with all lights off to see if current is jumping around. Then I will remove all spark plugs making sure to label them on a cardboard. I'll post pics of them.
I really want to ditch the factory routing of the plug wires. I would like to replace them and run them along the top edge of the valve covers with wire looms. Is this something I should do? My Vette has the stainless steel shorty headers with air injection tubes.
Thanks again!
C3
I really want to ditch the factory routing of the plug wires.
I would like to replace them and run them along the top edge of the valve covers with wire looms. Is this something I should do? My Vette has the stainless steel shorty headers with air injection tubes.Thanks again!
C3
Thread Starter
Racer
Joined: Feb 2007
Posts: 290
Likes: 0
From: Winchester CA
Well, here's an update. Dave (Birdsmith) came over today and we did a compression test on each cylinder. Here are the results:
#1 = 0 compression
#3 = 120 psi
#5 = 135 psi
#7 = 130 psi
#2 = 140 psi
#4 = 125 psi
#6 = 125 psi
#8 = 130 psi
After the compression test we took the valve cover off from the driver side and cranked the engine. We watched the rockers and they all moved up and down including the two at cylinder #1.
Is it time to pull this engine? It's a California 305 (LG4 computer controlled carburetor E4ME). Can I put in a bigger engine and still pass smog in California as long as slap on all the emmission crap on the replacement? Has anyone done this swap in California? Would I have to reuse the carburetor, distributor, and cam or can I go with aftermarket parts to put on a replacement engine? I want to make sure I know this important information before putting in a bigger engine with aftermarket carburetor, distributor and cam.
What do my fellow Corvette owners suggest...
Thank you,
C3
#1 = 0 compression
#3 = 120 psi
#5 = 135 psi
#7 = 130 psi
#2 = 140 psi
#4 = 125 psi
#6 = 125 psi
#8 = 130 psi
After the compression test we took the valve cover off from the driver side and cranked the engine. We watched the rockers and they all moved up and down including the two at cylinder #1.
Is it time to pull this engine? It's a California 305 (LG4 computer controlled carburetor E4ME). Can I put in a bigger engine and still pass smog in California as long as slap on all the emmission crap on the replacement? Has anyone done this swap in California? Would I have to reuse the carburetor, distributor, and cam or can I go with aftermarket parts to put on a replacement engine? I want to make sure I know this important information before putting in a bigger engine with aftermarket carburetor, distributor and cam.
What do my fellow Corvette owners suggest...
Thank you,
C3
Pro
Joined: Jun 2000
Posts: 664
Likes: 3
From: Denham Springs Louisiana
I haven't had to deal with the California stuff so hopefully someone will chime in.
As far as the 305, pull the intake and heads. you probably just need gaskets. You don't need to pull the motor and you can do the whole job start to finish pretty quick. (~30mins?) I would just check the heads by cleaning them and laying them across a flat piece of glass. Poor man's way to check for warpage. Or a local head shop can freshen ur heads up for fairly inexpensive.
By the way how much horsepower do you want? lol
As far as the 305, pull the intake and heads. you probably just need gaskets. You don't need to pull the motor and you can do the whole job start to finish pretty quick. (~30mins?) I would just check the heads by cleaning them and laying them across a flat piece of glass. Poor man's way to check for warpage. Or a local head shop can freshen ur heads up for fairly inexpensive.
By the way how much horsepower do you want? lol
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Drifting
Joined: May 2005
Posts: 1,629
Likes: 4
From: Somers CT
Pull the heads and inspect the valves, you probably have a burned valve. If the bottom end is in at least reasonable condition you can have the valve reground and the rest of the head inspected and if good you can reinstall them. No need to replace the engine for a simple burned valve, I'd pull the engine down and take a look.
Thread Starter
Racer
Joined: Feb 2007
Posts: 290
Likes: 0
From: Winchester CA
Hello fellow corvette enthusiasts,
I finally had the extra time away from work to continue with my mysterious engine problems. I recently removed the left cylinder head, and found a piece of the outer edge of piston #1 (no compression at this cylinder when tested 4 months ago) broken off!
I'm pretty sure now why I was having issues.
I've decided that I want to pull the engine out and replace with a crate, but not with another 305, oh no no no no no. I would like some guidance as to what my options are out there. I live in California, and I'm subjected to smog tests (visual and sniffer) every two years. The vette has the computer just like the 81's out there. What can I get for more umph and still pass smog? I'm very excited about taken on this project as I'm pretty much starting from scratch for engine options.
Thanks in advance!
I finally had the extra time away from work to continue with my mysterious engine problems. I recently removed the left cylinder head, and found a piece of the outer edge of piston #1 (no compression at this cylinder when tested 4 months ago) broken off!
I'm pretty sure now why I was having issues.I've decided that I want to pull the engine out and replace with a crate, but not with another 305, oh no no no no no. I would like some guidance as to what my options are out there. I live in California, and I'm subjected to smog tests (visual and sniffer) every two years. The vette has the computer just like the 81's out there. What can I get for more umph and still pass smog? I'm very excited about taken on this project as I'm pretty much starting from scratch for engine options.
Thanks in advance!
Drifting
Joined: Feb 2005
Posts: 1,738
Likes: 2
From: San diego ca
You can install any other small block you want in there and no smog tech would be able to tell the difference, assuming of course you dont plaster 350 stickers all over it
Your '80 doesnt have to pass anything more stringent than my 78 according to this so I wouldnt hesitate to get a new motor in there.
Things to remember are,
1.you wont be able to run Vortech heads - they dont have heat crossovers (AFAIK) and thus will make your EGR not function so watch out for crates with vortech heads.
2.1 pc rear seal motors have a different bolt pattern on the crank - you will not be able to reuse your flexplate, these are inexpensive though so I wouldnt let that worry you.
For conversation purposes this motor would be a good starting point...its got more power than what you have now, but lets face it, is still a bit of a dog.
Your '80 doesnt have to pass anything more stringent than my 78 according to this so I wouldnt hesitate to get a new motor in there.
Things to remember are,
1.you wont be able to run Vortech heads - they dont have heat crossovers (AFAIK) and thus will make your EGR not function so watch out for crates with vortech heads.
2.1 pc rear seal motors have a different bolt pattern on the crank - you will not be able to reuse your flexplate, these are inexpensive though so I wouldnt let that worry you.
For conversation purposes this motor would be a good starting point...its got more power than what you have now, but lets face it, is still a bit of a dog.
Last edited by fauxrs2; Sep 14, 2009 at 09:59 AM.