REBORN55
Frequent Contributor
Posts: 2241
Loc: DeSoto, Illinois. 62924
Reg: 01-21-01
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09-12-24 06:04 AM - Post#2873767
Hello--I have a modified 283 that lately has experienced an intermittent miss on acceleration. Started last year a tri five Nationals--accelerating and engine miss for about a block and then stopped--was good for the rest of season. Stored all winter with Stabil in a full tank of gas. Got it out this year--did fine for a little while then it started the miss on acceleration--no particular time or speed--shift gears and upon accel would miss and then go away. But I can drop speed down to about 20 mph in 4th gear and accelerate and no miss--I have replaced, plugs, wires, coil, (Pertronix ignition), dist springs, accel pump--reset float and drop--(edelbrock carburetor) adjusted timing numerous times--driven with ported or manifold vacuum. Drove to tri five nationals this year and had miss problem on and off there but when I drove home it ran great for 175 miles and then started acting up again. It has never failed to keep running. I also run premium gas in it for what it is worth--any help would be appreciated thanks
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Magnetocheck
Contributor
Posts: 538
Age: 70
Loc: Charlotte, NC, USA
Reg: 09-05-22
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09-12-24 06:21 AM - Post#2873770
In response to REBORN55
Those intermittent misses are really frustrating and hard to pin down. Sounds like the carb is OK since they don't usually have "off-and-on-again" problems. Something like this almost has to be electrical. Any problem with the distributor drive gear and/or cam walk? You can sometimes get a hint of this if the timing wanders at different RPMs when you check it with the light.
It could be a bad replacement coil. Others on the forum have reported them failing right out of the box, but I don't have any personal experience with Petronix stuff.
Since it seems to be affected a little by speed/gear choice, maybe check your vacuum advance with a MightyVac - make sure it's not sticking anywhere.
Bob
'65 Impala SS 396 Convertible
Member, National Impala Association
--It's weird being the same age as old people! |
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REBORN55
Frequent Contributor
Posts: 2241
Loc: DeSoto, Illinois. 62924
Reg: 01-21-01
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09-12-24 07:00 AM - Post#2873771
In response to Magnetocheck
Thank you--vacuum adv is working OK..I have 2 Pertronix flame thrower coils and results are the same with either one. As far as timing goes--have watched the marks and they seem steady at different rpm ranges--so not sure about it under load. what has got me buffaloed is that no miss when accelerating from around 20 mph in 4th gear no miss--thanks for response. also talked to edelbrock tech and really no help--was quick to tell me to change metering rods--ran better but still had intermittent miss
Edited by REBORN55 on 09-12-24 07:01 AM. Reason for edit: No reason given.
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Magnetocheck
Contributor
Posts: 538
Age: 70
Loc: Charlotte, NC, USA
Reg: 09-05-22
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09-12-24 07:50 AM - Post#2873775
In response to REBORN55
Sounds like you've done a lot of diag. work already!
Any chance you might have a bad ground or lose wires on the distributor? I have a Progression Ignition distributor in my Impala, and I traced an intermittent miss/stumble to a loose hot wire to the diz. I chose to run a dedicated 12V from the fuse block and had an issue with faulty crimp connector. After that I now solder all my under-hood connections and use heat shrink tubing. More work but fewer worries.
Bob
'65 Impala SS 396 Convertible
Member, National Impala Association
--It's weird being the same age as old people! |
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REBORN55
Frequent Contributor
Posts: 2241
Loc: DeSoto, Illinois. 62924
Reg: 01-21-01
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09-12-24 08:07 AM - Post#2873776
In response to Magnetocheck
When I had distributor out I redid couple of connections and checked the ground side according to Pertronix tech and all was good. I hate chasing these things and I hate spending any more money etc. with no hopes of finding problem..thanks again
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Shepherd
Valued Contributor
Posts: 3598
Loc: Lake George, NY
Reg: 11-11-15
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09-12-24 08:34 AM - Post#2873779
In response to REBORN55
You must use rfi resistant plug wires, not solid core, it can affect the pertronix module. One possibility.
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REBORN55
Frequent Contributor
Posts: 2241
Loc: DeSoto, Illinois. 62924
Reg: 01-21-01
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09-12-24 09:15 AM - Post#2873780
In response to Shepherd
I ran Accel super stock wires for a very long time--last two sets were Taylor Street Thunder wires--last set installed last year--when problem persisted put the old Accel wires back on (had no problem for years) and miss was still there thanks
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japete92
Frequent Contributor
Posts: 2330
Loc: No. Virginia
Reg: 01-18-13
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09-12-24 12:56 PM - Post#2873791
In response to REBORN55
Rotor? Distributor cap?
Wear on either, or both can cause a miss. A crack in the cap can let moisture in and also cause a miss.
Just a few thoughts.
Pete
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REBORN55
Frequent Contributor
Posts: 2241
Loc: DeSoto, Illinois. 62924
Reg: 01-21-01
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09-12-24 01:35 PM - Post#2873793
In response to japete92
Thanks--all have been replaced with new Echlin products
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GreatNorthWoods
"10th Year" Silver Supporting Member
Posts: 1644
Age: 82
Loc: Littleton, New Hampshire,...
Reg: 03-31-02
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09-13-24 02:05 AM - Post#2873806
In response to REBORN55
I know you said you replaced plugs and wires but that's what it sounds like to me. I recently had an intermittent miss that was solved with new plugs and wires. You may need to have the engine diagnosed on a machine to find it.
Vern
1953 Chevy Belair Sport Coupe - 355 Chevy V8, 700-R4, 4-wheel disc brakes, Ididit column, cruise/tilt,'59 Vette Steering Wheel, A/C
1930 DeSoto CK Business Coupe- 350 Chevy Crate V8, 4-wheel disc brakes, TH400, S-10 Rear, Heidt's IFS, A/C |
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bobb
Super Senior Member
Posts: 6856
Loc: paradise
Reg: 09-05-03
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09-14-24 09:15 AM - Post#2873862
In response to REBORN55
as noted, sounds like an electrical issue. loose something would be my guess. maybe a bad ignition switch? ghost in the machine sucks. maybe bypass ignition circuit.....sticking valve?
70 L camino, grampa engine, g-force 5 spd, road rage suspension. Pray first before all else fails. |
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japete92
Frequent Contributor
Posts: 2330
Loc: No. Virginia
Reg: 01-18-13
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09-14-24 03:14 PM - Post#2873873
In response to REBORN55
Thanks--all have been replaced with new Echlin products
After a tune up some time ago, I 'gained' a miss fire. Because I just did the job, I concluded I futzed something up. I did. The number 3 plug wire was not securely attached to the plug.
So, recommend also checking all the connections at the distributor and the plugs.
Also, were the wires fabricated from a universal kit? It is not hard to get a connector(s) futzed. Did that too; once. Pain in the butt to track down. Had to 'take down' the wires individually until I found the culprit.
Just some suggestions.
Pete
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REBORN55
Frequent Contributor
Posts: 2241
Loc: DeSoto, Illinois. 62924
Reg: 01-21-01
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09-16-24 01:56 PM - Post#2873924
In response to japete92
thanks for all the responses---did a little rewiring of primary connections today--found out Taylor wires are now Chinese made --in response to some of ideas all cylinders are hitting at idle or just off idle--will being going to car show this weekend and see how it drives will be put away for winter running good or not--THANKS again--all responses have been tried -- enjoy
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G. Baker
Contributor
Posts: 113
Loc: Ontario Canada
Reg: 12-18-15
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09-19-24 06:17 AM - Post#2874011
In response to REBORN55
I had a similar situation on a 327/300 I believe.
Traced to a bad Motor mount and on acceleration, the motor would swing enough to short out one of the plug wires or coil feed. Long time ago!
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REBORN55
Frequent Contributor
Posts: 2241
Loc: DeSoto, Illinois. 62924
Reg: 01-21-01
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10-02-24 05:59 AM - Post#2874366
In response to G. Baker
Little update--took the AC plugs out--less than 1000 miles on them--replaced with the old NGK plugs--also less than 1000 miles on them. Bumped timing up little bit more and added some Heet to gas tank--filled it with premium and took to local car show---drove around 50 miles round trip and it ran great. So it is being put away for the winter and next spring will see how it runs. Adding Stabil and covering up--THANKS all
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