'70 454 Starting Problem
Thread Starter
Advanced
Joined: May 2006
Posts: 75
Likes: 0
'70 454 Starting Problem
Still having problems starting. When it tries to start, it runs very rough with the engine rocking heavily. Changed plugs, wires and install new rotor cap. Distributor cap looked OK. Any ideas? Could the clutch have anything to do with this ? Guessing - have no idea.
Racer
Joined: Mar 2006
Posts: 366
Likes: 1
From: Houston Texas
I would doubt it is clutch related, but it could be anything relating to timing or carb tuning. I'd suggest you check out lars' papers at:
http://wiki.corvettefaq.com/index.php?title=Tuning
and do the the timing exercise first.
http://wiki.corvettefaq.com/index.php?title=Tuning
and do the the timing exercise first.
Melting Slicks
Joined: May 2001
Posts: 2,131
Likes: 4
From: May help you? You can sure as hell try!
Recheck firing order, wire sequence and that all the wires are firmly seated in the cap and on the plugs. If that looks OK, remove and check plug gaps. You may be able to tell which cylinder(s) aren't firing by looking for absence of carbon. Since you probably haven't had the engine running long since the plug change, there won't be much on any of them but the cylinders that are firing should have a trace of it at least.
As dumb as it sounds, getting wires mixed is easy to do. Also, check to see if the plugs are the correct type (big blocks used two different seat style plugs). A friend of mine had issues with a small block where the plug reach was incorrect and the dome of the piston would just barely touch the electrode of the plug. He found the electrodes had been bent closed on a couple of cylinders causing it to misfire.
Since you just changed wires, plugs and cap my bet is the problem is one of these, epecially if the car was running OK prior to the change.
As dumb as it sounds, getting wires mixed is easy to do. Also, check to see if the plugs are the correct type (big blocks used two different seat style plugs). A friend of mine had issues with a small block where the plug reach was incorrect and the dome of the piston would just barely touch the electrode of the plug. He found the electrodes had been bent closed on a couple of cylinders causing it to misfire.
Since you just changed wires, plugs and cap my bet is the problem is one of these, epecially if the car was running OK prior to the change.
Safety Car
Joined: Jun 2004
Posts: 4,652
Likes: 80
From: Lakeland Florida
I would start with the wiring order again. If you changed the wires, then you may be off one hole all the way around, but it smay not/should not start if that was the case. If it is rocking, or very rough, then you might have crossed 2 plug wires.
The timing may also have a lot to do with this. I have a 73 454 that has its own running issues. I found the timing to be one of the reasons for the rough running engine in mine.
Get the paper that justanotherdoe suggested from Lars titled
"How to Set Your Timing for Peak Performance
(Non-HEI)" and start from there.
kdf
The timing may also have a lot to do with this. I have a 73 454 that has its own running issues. I found the timing to be one of the reasons for the rough running engine in mine.
Get the paper that justanotherdoe suggested from Lars titled
"How to Set Your Timing for Peak Performance
(Non-HEI)" and start from there.
kdf
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Advanced
Joined: May 2006
Posts: 75
Likes: 0
I was having a strting problem before I changed the plugs and wires.
What I forgot to mention the first time, is that I changed the wires because, when the engine was running the last time with the old wires (shielded), Itook my finger and pressed down on one of the wires at the distributor cap, and the engine tried to shut off. When I released, the engine kept running. That is the reason for the new wires. So, it was running with the new plugs.
What I forgot to mention the first time, is that I changed the wires because, when the engine was running the last time with the old wires (shielded), Itook my finger and pressed down on one of the wires at the distributor cap, and the engine tried to shut off. When I released, the engine kept running. That is the reason for the new wires. So, it was running with the new plugs.
