 Still a miss at 4,000 RPM..., Backfiring at WOT, even with all new ignition components |
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| ThePaintedMan |
 May 7 2013, 10:47 AM
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Advanced Member  Group: Members Posts: 3,887 Joined: 6-September 11 From: St. Petersburg, FL Member No.: 13,527 Region Association: South East States 
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Hello all,
Tonight I'll be buttoning up the car for the first DE this weekend (if it passes tech this time), and I've got one last thing I'd like to track down before hitting the track. A few times I've ventured into the 4,000 RPM range and I get a lot of backfiring, primarily from the passenger side carb, I think. Otherwise it runs great at all of the other RPMs. Right now it's got a crappy 009 distributor with points, but seems to work well enough so I've decided to stay with it to keep the headaches down. Would it be logical to assume that the high RPM misfire is because of spark scatter with the points setup? I ask because I have a Pertronix unit ready to go on a spare distributor that I'd like to try, but with only a few days until the DE, I'm not going to go poking and prodding unless there is a good chance this could fix the issue. Otherwise I'll just short-shift (IMG:style_emoticons/default/smile.gif) Whatcha think? |
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| ThePaintedMan |
May 9 2013, 09:43 AM
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Advanced Member Group: Members Posts: 3,887 Joined: 6-September 11 From: St. Petersburg, FL Member No.: 13,527 Region Association: South East States
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(IMG:style_emoticons/default/idea.gif) Guess I've been babying her too much. I think it's my lack of funds and ability to rebuild an engine that causes me to be so careful with it. But if you guys say go for it, I don't need to be told twice (IMG:style_emoticons/default/smile.gif)
The car is at the shop getting aligned now. When I get it home, hopefully tonight, I'll play around with the synch some more and triple check for leaks. Chris, I have a quick question for you regarding your cable linkage. I'll send you a PM. |
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Posts in this topic
ThePaintedMan Still a miss at 4,000 RPM... May 7 2013, 10:47 AM
DBCooper
Hello all,
Tonight I'll be buttoning up th... May 7 2013, 12:12 PM
ThePaintedMan
You've only ventured to 4000 rpm "a few... May 7 2013, 12:24 PM DBCooper
DB, what is your name by the way? I've never ... May 7 2013, 08:23 PM jmill What fuel pump do you have? Could also be you don... May 7 2013, 08:52 PM 1988Hawk
Hello all,
Tonight I'll be buttoning up th... May 8 2013, 03:04 PM ThePaintedMan As far as I know, I've got plenty of fuel volu... May 8 2013, 03:32 PM r_towle First off, you ARE a wuss.....at a de, redline is ... May 8 2013, 07:35 PM jmill Might be an ignition issue but if not and your loo... May 8 2013, 08:13 PM ThePaintedMan Well I threw everything I had at it tonight. Did i... May 8 2013, 09:38 PM old dog
Well I threw everything I had at it tonight. Did ... May 8 2013, 10:12 PM Racer Chris Heck, I rev my street engine past 4K routinely - b... May 9 2013, 08:21 AM mepstein If I didn't rev my little 1.7 past 4K, I would... May 9 2013, 08:32 AM rhodyguy back firing on accel or decel? exhaust only, not o... May 9 2013, 09:59 AM ThePaintedMan
back firing on accel or decel? exhaust only, not ... May 9 2013, 10:04 AM ThePaintedMan Hi guys,
Running out of time, but at least I thi... May 9 2013, 07:39 PM jmill Gasket is correct. Hole is correct. A vacuum lea... May 9 2013, 08:30 PM ThePaintedMan
Gasket is correct. Hole is correct. A vacuum le... May 9 2013, 08:36 PM r_towle easy test
Switch carbs side to side and see if th... May 9 2013, 08:40 PM jmill That's a good linkage and wouldn't suspect... May 9 2013, 09:13 PM type2man You might want to check the plug wires or cap for ... May 9 2013, 09:41 PM messix check the dwell of the points, using gap only isn... May 9 2013, 09:49 PM rhodyguy george, i consider the carb to intake gaskets a ON... May 10 2013, 08:25 AM ThePaintedMan I agree with you Kevin, they are a one time use. N... May 10 2013, 11:49 AM monkeyboy I would venture to guess that either the throttle ... May 10 2013, 12:05 PM ThePaintedMan
I would venture to guess that either the throttle... May 10 2013, 12:18 PM jmill With 55 idles, 140 mains and the F7 ET you shouldn... May 10 2013, 09:19 PM DBCooper That sounds like a lean condition alright. It wou... May 11 2013, 06:30 AM rhodyguy do your DE with a light foot. sounds like it runs ... May 11 2013, 06:52 AM ThePaintedMan Well you guys were right on a number of accounts. ... May 13 2013, 04:02 PM messix
Well you guys were right on a number of accounts.... May 13 2013, 06:57 PM r_towle How far are you from TC or from URY?
Might help to... May 13 2013, 05:54 PM Racer Chris If you can partially mitigate the symptoms by enga... May 13 2013, 06:41 PM jmill
If you can partially mitigate the symptoms by eng... May 13 2013, 08:14 PM ThePaintedMan Again, thanks for the ongoing advice gents. I hamm... May 13 2013, 08:22 PM messix
Again, thanks for the ongoing advice gents. I ham... May 13 2013, 09:46 PM rhodyguy when it's dark outside start the car and mist ... May 14 2013, 06:55 AM r_towle question.
Can you simulate this with no load?
So,... May 14 2013, 11:26 AM ThePaintedMan
when it's dark outside start the car and mist... May 14 2013, 11:46 AM Racer Chris
If it only happens under load, that's usuall... May 14 2013, 02:32 PM r_towle
If it only happens under load, that's usual... May 14 2013, 02:43 PM yeahmag A cheat for the manifold to head gaskets is to eit... May 14 2013, 12:00 PM messix I wouldn't go exposing your self to 40k of vol... May 14 2013, 07:52 PM ThePaintedMan Played around some more last night. I can still so... May 15 2013, 07:19 AM ThePaintedMan Checked the valves, everything was within spec.
... May 16 2013, 08:29 PM r_towle Use some light rtv gasket between the phenolic spa... May 16 2013, 08:32 PM r_towle So, you just replaced the wires, not too long ago.... May 16 2013, 08:33 PM jmill My SWAG is still the accelerator pumps. I'm n... May 16 2013, 08:51 PM jmill Just bombing around I see this fairly complete kit... May 16 2013, 09:00 PM r_towle
Just bombing around I see this fairly complete ki... May 17 2013, 06:16 AM timothy_nd28 I'm new to this thread, by all means use my ca... May 16 2013, 11:33 PM rhodyguy so you noted arching on all 4 wires? unfortunately... May 17 2013, 07:50 AM stugray If the carbs have a vacuum leak from the shafts, c... May 17 2013, 08:39 AM rhodyguy george, are the end washers, item #30 in the explo... May 17 2013, 09:54 AM ThePaintedMan From all the diagrams and stuff I've poured ov... May 17 2013, 01:05 PM r_towle Early style carbs have three or four different acc... May 17 2013, 02:20 PM URY914 My car used to arc at the dizzy cap wires. One of ... May 17 2013, 02:30 PM yeahmag Have you verified wirh a timing light that nothing... May 17 2013, 07:30 PM jmill
From all the diagrams and stuff I've poured o... May 17 2013, 08:49 PM ThePaintedMan Well I cleaned and re-lubed my SVDA dizzy and went... May 20 2013, 07:23 AM yeahmag Weak or failing coil? May 20 2013, 08:25 AM ThePaintedMan
Weak or failing coil?
Good call Aaron. That wou... May 20 2013, 08:35 AM stugray
I agree. Although the realignement of the plates... May 20 2013, 08:39 AM ThePaintedMan
I agree. Although the realignement of the plates... May 20 2013, 09:44 AM ThePaintedMan Sorry to drag this back out, but I thought I would... May 22 2013, 07:58 PM timothy_nd28 Take that extra set of carbs you have laying aroun... May 22 2013, 08:25 PM yeahmag Have you verified with a timing gun that you aren... May 23 2013, 09:35 AM r_towle Weber pump part numbers
According to redline webe... May 23 2013, 10:11 AM ThePaintedMan Thanks Tim, I'm considering it.
Aaron, I time... May 23 2013, 12:07 PM r_towle
Rich, I knew about the difference in diaphragms.... May 23 2013, 02:35 PM 904svo Remove the Compfire and try it with stock ignition... May 23 2013, 12:23 PM rhodyguy :agree: May 23 2013, 12:37 PM ThePaintedMan It was doing it with the stock ignition, as I have... May 23 2013, 12:53 PM carr914 Maybe it's time for one of these
http://www.m... May 23 2013, 01:07 PM yeahmag The MSD won't help if it's not an ignition... May 23 2013, 02:04 PM toolguy Have you tried a new distributor CAP. . arcing ins... May 23 2013, 02:15 PM ThePaintedMan Cap and rotor are brand new as well (on both types... May 23 2013, 03:02 PM r_towle
Cap and rotor are brand new as well (on both type... May 23 2013, 03:07 PM ThePaintedMan
Yes sir....you got it.
Like I said...btdt...
Y... May 23 2013, 03:13 PM timothy_nd28
It's a ten minute job, with instant results ... May 23 2013, 03:33 PM r_towle We just wanted to fill everyone in on what has bee... May 23 2013, 03:12 PM ThePaintedMan Yeah, yeah Tim, I know :) This is more of a learn... May 23 2013, 05:36 PM ThePaintedMan Yeah, yeah Tim, I know :) This is more of a learn... May 23 2013, 05:43 PM ThePaintedMan The only other things I want to take a look at whe... May 23 2013, 06:17 PM jmill If I recall correctly there is a ball check in #10... May 23 2013, 08:47 PM r_towle position 2 "would" make the lever depres... May 24 2013, 07:33 AM ThePaintedMan
position 2 "would" make the lever depre... May 24 2013, 08:50 AM yeahmag Can you remind me if this happens at steady thrott... May 24 2013, 11:01 AM ThePaintedMan
Can you remind me if this happens at steady throt... May 24 2013, 11:08 AM ThePaintedMan Okay, this is hard to explain... but I think I fou... May 24 2013, 06:43 PM carr914 :unsure: :wacko: :DRUNK: May 24 2013, 07:09 PM jmill That would do it. May 24 2013, 08:47 PM r_towle Hope that does it. May 25 2013, 06:58 PM ThePaintedMan ...And it didn't do it :)
I dinked around wi... May 26 2013, 07:13 PM carr914 George, try changing out the Fuel Pump. When you c... May 27 2013, 08:40 PM rhodyguy is the fuel pump elevation = or below the tank out... May 27 2013, 09:23 PM timothy_nd28 You happen to have another set of carbs laying aro... May 27 2013, 09:36 PM ThePaintedMan T.C. and Kev, the fuel pump is brand new and it is... May 28 2013, 08:05 AM Mblizzard George I had to go to 75s on the idle jets before ... May 28 2013, 08:23 AM |
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