C2 1965 Engine Miss - Page 2 - CorvetteForum - Chevrolet Corvette Forum Discussion

Notices
C1 & C2 Corvettes General C1 Corvette & C2 Corvette Discussion, Technical Info, Performance Upgrades, Project Builds, Restorations

[C2] 1965 Engine Miss

Old 10-08-2018, 04:58 PM
  #21  
rnixon
CF Senior Member
 
rnixon's Avatar
 
Member Since: Feb 2015
Location: Agawam MA.
Posts: 118
Thanks: 0
Thanked 10 Times in 7 Posts
Default

Originally Posted by 59BlueSilver View Post


Yes, it seems to.
If your motor runs strong at wide open throttle, and what you are experiencing at a normal cruising speed ,can be described as almost imperceptible , only felt by the driver, the passenger unaware of anything abnormal. If that's an accurate description,if while driving you're not always sure yourself it's there and sometimes have to concentrate on it to feel it, then there is a good chance there is a restriction in one of the main carburetor jets
Something as small in length and diameter as a human eyelash, is enough to cause the exact condition described above

Last edited by rnixon; 10-08-2018 at 05:00 PM.
rnixon is offline  
Old 10-08-2018, 07:01 PM
  #22  
DansYellow66
CF Senior Member
 
DansYellow66's Avatar
 
Member Since: Jan 2003
Location: Central Arkansas
Posts: 10,092
Thanked 562 Times in 504 Posts
Default

Originally Posted by Little red 63 View Post


I have a Carter/Edelbrock on mine so I can just turn the two screws on the front of the car to Richen it up some and that is what I did. As others have said by looking at your plugs it does appear you are a little bit Lean.
That will only richen up the idle (and possibly a bit on the transition circuit). It won't richen (or lean out) the primary or secondary systems.
DansYellow66 is offline  
Old 10-08-2018, 07:46 PM
  #23  
tbarb
CF Senior Member
 
Member Since: May 2014
Posts: 2,133
Thanked 205 Times in 195 Posts
Default

What type of carburetor is on the engine, does it have threaded air bleeds. How long have you been experiencing this surge condition and what rpm does this usually occur.

Raising the float level will start the main circuit sooner that may be why you noticed a change.
tbarb is offline  
Old 10-11-2018, 04:12 PM
  #24  
59BlueSilver
CF Senior Member
Thread Starter
 
59BlueSilver's Avatar
 
Member Since: Apr 2013
Location: Arlington TX
Posts: 2,484
Thanked 115 Times in 99 Posts
Default

I pulled and plugged the dist. Hose, couldnít really tell if there was much of a change. What does that mean? Itís noticeable in all speed and rpm except full acceleration, more noticeable at a steady, low end range.
The carb is a Holley 4779-9.
59BlueSilver is offline  
Old 10-11-2018, 04:29 PM
  #25  
59BlueSilver
CF Senior Member
Thread Starter
 
59BlueSilver's Avatar
 
Member Since: Apr 2013
Location: Arlington TX
Posts: 2,484
Thanked 115 Times in 99 Posts
Default


Number 2

Number 3

Number 4

Number 5

Number 6

Number 7

Number 8
59BlueSilver is offline  
Old 10-11-2018, 06:45 PM
  #26  
59BlueSilver
CF Senior Member
Thread Starter
 
59BlueSilver's Avatar
 
Member Since: Apr 2013
Location: Arlington TX
Posts: 2,484
Thanked 115 Times in 99 Posts
Default

Update! Went for another drive, it’s really a lot more noticeable at 40mph, 1500 rpm. Same whether dist. Is plugged or unplugged.
59BlueSilver is offline  
Old 10-11-2018, 06:50 PM
  #27  
DansYellow66
CF Senior Member
 
DansYellow66's Avatar
 
Member Since: Jan 2003
Location: Central Arkansas
Posts: 10,092
Thanked 562 Times in 504 Posts
Default

Ehh - probably could use some new plugs although that may not be the direct cause of your missing issue. I would check it in the dark for spark plug wire leaks. Do you have points still in the distributor - although I don't think burnt points or mis-gapped points would behave as you are describing? Also, do you have any idea what the timing is set at?
DansYellow66 is offline  
Old 10-11-2018, 06:55 PM
  #28  
59BlueSilver
CF Senior Member
Thread Starter
 
59BlueSilver's Avatar
 
Member Since: Apr 2013
Location: Arlington TX
Posts: 2,484
Thanked 115 Times in 99 Posts
Default

Originally Posted by DansYellow66 View Post
Ehh - probably could use some new plugs although that may not be the direct cause of your missing issue. I would check it in the dark for spark plug wire leaks. Do you have points still in the distributor - although I don't think burnt points or mis-gapped points would behave as you are describing? Also, do you have any idea what the timing is set at?
No, itís HEI. The timing is set at 12 deg. Tonight Iíll check the wires.
59BlueSilver is offline  
Old 10-11-2018, 06:59 PM
  #29  
MikeM
CF Senior Member
 
Member Since: Mar 2003
Location: Greenville, Indiana
Posts: 21,788
Thanked 707 Times in 604 Posts
Default

I'd put a new set of plugs in that plug and see if that miss goes away. Next step is to find out why your new set of plugs will shortly look like the ones in your pictures.
MikeM is online now  
Old 10-11-2018, 08:37 PM
  #30  
59BlueSilver
CF Senior Member
Thread Starter
 
59BlueSilver's Avatar
 
Member Since: Apr 2013
Location: Arlington TX
Posts: 2,484
Thanked 115 Times in 99 Posts
Default

Originally Posted by DansYellow66 View Post
Ehh - probably could use some new plugs although that may not be the direct cause of your missing issue. I would check it in the dark for spark plug wire leaks. Do you have points still in the distributor - although I don't think burnt points or mis-gapped points would behave as you are describing? Also, do you have any idea what the timing is set at?
Just got back from checking, absolutely no leaks at all, even at 2000 rpm.
59BlueSilver is offline  
Old 10-11-2018, 08:40 PM
  #31  
59BlueSilver
CF Senior Member
Thread Starter
 
59BlueSilver's Avatar
 
Member Since: Apr 2013
Location: Arlington TX
Posts: 2,484
Thanked 115 Times in 99 Posts
Default

Originally Posted by MikeM View Post
I'd put a new set of plugs in that plug and see if that miss goes away. Next step is to find out why your new set of plugs will shortly look like the ones in your pictures.
i can try a new set of plugs, but I donít think I need new wires (see post). Have we eliminated the carburetor?
59BlueSilver is offline  
Old 10-12-2018, 07:15 AM
  #32  
MikeM
CF Senior Member
 
Member Since: Mar 2003
Location: Greenville, Indiana
Posts: 21,788
Thanked 707 Times in 604 Posts
Default

Originally Posted by 59BlueSilver View Post


i can try a new set of plugs, but I donít think I need new wires (see post). Have we eliminated the carburetor?

Is that the same set of plugs shown in your first photos? Maybe it's just the camera angle and lighting? In general, it looks like the tips are burning hot/clean with heavy deposits on the ground electrode?

Doesn't look like a carburetor problem to me. Looks like oil to me on some of them but maybe an expert has a better slant on things.
MikeM is online now  
Old 10-12-2018, 07:44 AM
  #33  
Tiros
CF Senior Member
 
Tiros's Avatar
 
Member Since: Jun 2005
Location: Somewhere in NJ
Posts: 429
Thanked 25 Times in 24 Posts
Default

Originally Posted by 59BlueSilver View Post
I installed new spark plugs last year, they still look good. And a new HEI module last spring. It probably could use new spark plug wires though.

Leaking HV is not the only failure mode possible wrt plug wires. What about the cap and rotor too? Looks to me like some holes aren't getting full spark. If it was a fuel problem wouldn't all the plugs look more or less the same? A compression test would not hurt.

Last edited by Tiros; 10-12-2018 at 07:46 AM.
Tiros is offline  
Old 10-12-2018, 08:03 AM
  #34  
Frankie the Fink
CF Senior Member
Support Corvetteforum!
 
Frankie the Fink's Avatar
 
Member Since: Aug 2007
Location: Orlando Metro Area Florida
Posts: 44,446
Thanked 2,724 Times in 2,214 Posts
Default

MikeM called it..... Those plugs are clearly "hot" enough to burn through some cruddy build up....the tips of the electrodes are clean but the rear of the top electrode is cruddy in almost all cylinders, along with the ring at the top of the threads. Something is going on....here are the plugs from my 61 - note the difference..



Last edited by Frankie the Fink; 10-12-2018 at 08:03 AM.
Frankie the Fink is online now  
Old 10-12-2018, 09:03 AM
  #35  
DSR
CF Senior Member
 
Member Since: Jun 2006
Location: Durham ON
Posts: 900
Thanks: 0
Thanked 24 Times in 22 Posts
Default

Originally Posted by 59BlueSilver View Post


I installed new spark plugs last year, they still look good. And a new HEI module last spring. It probably could use new spark plug wires though.

Don't overlook the wires. After chancing down a miss with my motor last year, it turned out to be 3 of the wires were not making a good connection at the spark plugs. A new set of wires fixed the miss.
DSR is offline  
Old 10-12-2018, 09:20 AM
  #36  
59BlueSilver
CF Senior Member
Thread Starter
 
59BlueSilver's Avatar
 
Member Since: Apr 2013
Location: Arlington TX
Posts: 2,484
Thanked 115 Times in 99 Posts
Default

Originally Posted by Tiros View Post
Leaking HV is not the only failure mode possible wrt plug wires. What about the cap and rotor too? Looks to me like some holes aren't getting full spark. If it was a fuel problem wouldn't all the plugs look more or less the same? A compression test would not hurt.
I ran it when I pulled the plugs. Here are the results.
Cylinder Compression Test
#1 - 140, #2 - 152, #3 - 145, #4 - 143, #5 - 140, #6 - 145, #7 - 146, #8 - 140

59BlueSilver is offline  
Old 10-14-2018, 11:13 AM
  #37  
Kelly Burnside
CF Senior Member
 
Member Since: Jan 2003
Location: Screw you guys, I'm going home.... Homeless in Ohio
Posts: 3,110
Thanks: 0
Thanked 1 Time in 1 Post
Default

Originally Posted by 59BlueSilver View Post
Running along at about 60 mph, I feel the car jerking or a miss (don’t know the technical name) ever so slightly. It was worse until I adjusted the front Holley float but it still does it. How can I tell if it’s electrical or fuel related?

Update! Went for another drive, it’s really a lot more noticeable at 40mph, 1500 rpm. Same whether dist. Is plugged or unplugged.
Let me give you my experience with my 65 327/365 corvette. I had issues early on with the engine breaking up around 3000 rpm. I sent the carburetor and eventually the distributor out for Eric Jackson to be rebuild. Both came back but after installing the carburetor, I notice a slight surging. I thought it was the distributor as I was still experiencing the high rpm breaking up. After replacing the distributor. I noticed that when the choke was on and/or driving the vette it still had the weird issue while driving.
After 1 1/2 years of experiencing the weird surging I replaced everything possible electrical related during that time. What was replaced - spark plug wires, new coil, new ballast resistor, spark plugs (twice), distributor springs, vacuum advance canister (three times), distributor cap (twice)... Everyone I talked to or who worked on the car said it was electrical related. I did change the jets on the carb as well as the pump discharge nozzle.
What I was experiencing after 1 1/2 years of trying to figure out the issue - vette would pop (after fire) out the drivers side exhaust when around 1100 - 1500 rpm while choke was on. I also experienced the trailer hitching around 1000 - 15000 rpm at 35 - 40 mph's. I had taken the car to several places and had several people look at the car. They either said carb or distributor was the issue. Finally, while trying to adjust the fuel mixture on the carburetor, the fuel mixture screw on the drivers side would not adjust out.
Finally after 1 1/2 years of frustration, I called Chicago Corvette and tried to order a restored 2818-1 carburetor. They actually told me they felt it was the distributor as well and not the carb and talked me out of buying the carburetor. Went back out to the vette, tried to adjust the carb as well as put the original springs in the distributor. Still had the issues of the 1100 - 1500 rpm popping/surge. I call Chicago Corvette and told them to send me the carb. After replacing the carburetor, the engine ran like a champ. No more issues. Issue turned out to be the rebuilt/restored carburetor.

I wouldnt rule out the carburetor as I have had what appears to be the same symptoms that 59BlueSilver is having.

What I learned from this (frustrating) experience, just because your carburetor was rebuilt/restored by what was supposed to be the best rebuilders in the country, doesnt mean it was rebuilt correctly.

Last edited by Kelly Burnside; 10-14-2018 at 11:26 AM. Reason: added other quote
Kelly Burnside is offline  


Thread Tools
Search this Thread
Sponsored Ads
Vendor Directory

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: