Engine Problem - Advice Needed
Instructor
Joined: Aug 2004
Posts: 204
Likes: 16
From: Holly Springs NC
same here
Originally Posted by SKYCOP1
For what it's worth, I had a 350 that rounded the lobe off the cam in a short time, pulled the valve cover off and there it was you could see it while the engine was running. The rocker arm on the intake side was quivering moving ever so slightly.
Gook Luck in your hunt
Tom
Gook Luck in your hunt
Tom
Thread Starter
Drifting
Joined: Mar 2003
Posts: 1,608
Likes: 3
From: Canberra AUSTRALIA
St. Jude Donor '05-'06
Originally Posted by 75blackray
my car had a miss in the number 8 cylinder when i first got it. Couldn't find out what it was. Ended up being that lobe on the camshaft. It could be possible that is whats going on.
I have my fingers crossed it is not this.
wcinxs,
I am getting back on the engine analyser tonight. Guess we will see what is going on. Fingers crossed for a vaccum leak.
Thanks again guys,
Pete
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Originally Posted by stingry
wcinxs,
I am getting back on the engine analyser tonight. Guess we will see what is going on. Fingers crossed for a vaccum leak.
Thanks again guys,
Pete
I am getting back on the engine analyser tonight. Guess we will see what is going on. Fingers crossed for a vaccum leak.
Thanks again guys,
Pete
Melting Slicks
Joined: Jan 2004
Posts: 2,527
Likes: 1
From: St. Petersburg, Fl///Columbus, Ohio
Keep us Posted!!!! I've got 4 Techs (myself Included) at University Chevy in Tallahassee guessing what's wrong with your car!!!!! If you don't have it figured out by Monday your welcome to bring it here!!!
For what it's worth were guessing is a plug, wire or cap with one vote for a wiped lobe in your distributer
For what it's worth were guessing is a plug, wire or cap with one vote for a wiped lobe in your distributer
Last edited by jcswm; Nov 19, 2004 at 04:17 PM.
Instructor
Joined: Dec 2002
Posts: 242
Likes: 0
From: Port Orchard Washington
With a large vacuum leak through the headlight fitting, when the intake valve opens and the cylinder descends, the vacuum is not pulled through the carb, causing very limited residual vapor residing in the runner from the fitting to the valve to be pulled in. Atomized fuel is required for internal combustion, vapor won't support. The dilution is so great that any mixture pulled in to the cylinder won't fire at all. Vapor will build in the exhaust causing a fuel smell. Because of its location (#8) I suspect the headlights first and not a valve or spark issue.
It is a quicker check to pull the line and cap while running then pull a plug.
Although I could be totally hosed. But my experience says no.
It is a quicker check to pull the line and cap while running then pull a plug.
Although I could be totally hosed. But my experience says no.
Thread Starter
Drifting
Joined: Mar 2003
Posts: 1,608
Likes: 3
From: Canberra AUSTRALIA
St. Jude Donor '05-'06
Originally Posted by Missileman
With a large vacuum leak through the headlight fitting, when the intake valve opens and the cylinder descends, the vacuum is not pulled through the carb, causing very limited residual vapor residing in the runner from the fitting to the valve to be pulled in. Atomized fuel is required for internal combustion, vapor won't support. The dilution is so great that any mixture pulled in to the cylinder won't fire at all. Vapor will build in the exhaust causing a fuel smell. Because of its location (#8) I suspect the headlights first and not a valve or spark issue.
It is a quicker check to pull the line and cap while running then pull a plug.
Although I could be totally hosed. But my experience says no.
It is a quicker check to pull the line and cap while running then pull a plug.
Although I could be totally hosed. But my experience says no.
Missileman,
You are right...but JCSWM is also right also. Talk about a mixed bag of problems and I am still not there.
BOTH Headlight relay valves leak like taps. Put smoke back on and looked up front. Poured out. Blocked the vaccum fitting which is on top of #8 and it was noticeably smoother. I also suspect there may be a minor leak in the brake booster (which is new Cardone rebuild) but will check with a Minvac next week. Temp in manifold changed from 100-150 degrees difference to about 50-80 degrees difference.
The new AC DELCO Distributor Cap and Rotor were rubbing ie rotor trip was gouging the cap contacts???? On the sun engine analyzer the spark was all over the place. I put the old rotor in first and it improved, put the old cap back on it got better again. After engine balance test it is now randomly showing other cylinders failing. Wierd eh!
I still have to test it with new leads (forgot to take them to the workshop with car) and try a different plug. Also need to test the booster as stated. I may change its pickup to position on the base of the carb so it is not beating up on #8 by itself.
Thanks for you help so far guys.
I am off to Suuth Georgia corvettes tomorrow to put it on the dyno. Hopefully some of those guys will have some thoughts as well.
Thread Starter
Drifting
Joined: Mar 2003
Posts: 1,608
Likes: 3
From: Canberra AUSTRALIA
St. Jude Donor '05-'06
Originally Posted by jcswm
Keep us Posted!!!! I've got 4 Techs (myself Included) at University Chevy in Tallahassee guessing what's wrong with your car!!!!! If you don't have it figured out by Monday your welcome to bring it here!!!
For what it's worth were guessing is a plug, wire or cap with one vote for a wiped lobe in your distributer
For what it's worth were guessing is a plug, wire or cap with one vote for a wiped lobe in your distributer
I may just take you guys up on your offer in the near future. Let me see how I go on the weekend at the dyno. Any of you guys going up to Moultrie? If so my cell is 850 819 2035. We should be there around 11am and staying till about 2pm. Then we are off to SOuth Georgia Corvette in Thomastown.
If I don't sort it out this weekend it will be out of commission for a couple of weeks because Pinky is rebuilding my coulmn starting next week and I am also puling my steering box.
Thread Starter
Drifting
Joined: Mar 2003
Posts: 1,608
Likes: 3
From: Canberra AUSTRALIA
St. Jude Donor '05-'06
Originally Posted by wcsinx
I really doubt that's what it is. Please before you yank out any hair, just pull out the spark plug, plug it back into the boot, ground it anywhere (just let it sit on the edge of the plug hole), then crank the engine a few times. If you don't get a bright blue (very obvious) spark, then you know where the problem is.
Will do it in the morning though.
Pete
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Thread Starter
Drifting
Joined: Mar 2003
Posts: 1,608
Likes: 3
From: Canberra AUSTRALIA
St. Jude Donor '05-'06
JSWM, Missileman, WCSINX
Originally Posted by jcswm
YES, I'll be at the swap meet!!!! but we will get there around 9-9:30.... I'll try to remember to call you If we're still there at 11
I didn't get there till about 11AM. Not a lot of vette stuff but got some handy hardware (screws and stuff) and a storage compartment trim.
We dynoed the car today at South Georgia Corvette. It is definetly a vaccum issue sucking air into #8. At 5000 RPM the engine is 0.4% leaner on the right side then the left. I was wrong with my quoting of rich/lean before. It was 22% at idle whcih is lean. My little knowledge of fuel/air made me think this is rich.
The engine still turned 226 HP at 4600 RPM and 290 FT/LBS at 2500 RPM.Absolutely screamed. The faster it revved the smoother it got.
Not sure if the dyno shut down because my tires were not rated higher or not. I thought that HP kept going up with RPM.
Is running a tad rich so I need to get the carb slightly tweaked.
Its off the road for a couple of weeks till I get my steering sorted, wheels powdercoated and do some more of my interior. I will also fix the vaccum leak in the meantinme.
Thanks again for your help.
You to MISSILEMAN and WCSINX. Will let you know results after I get the vaccum all sorted.
Cheers,
Pete
