 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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Posts in this topic
ThePaintedMan Still a miss at 4,000 RPM... May 7 2013, 10:47 AM
ThePaintedMan Thanks for the offer Mike, but I don't think t... May 28 2013, 10:32 AM rhodyguy prob not. May 28 2013, 10:58 AM ThePaintedMan Thanks for all of the replies. Since I've trie... May 28 2013, 02:01 PM timothy_nd28 consider re-adjusting your valves to 0.004", ... May 28 2013, 02:44 PM ThePaintedMan Good call Tim, I might just try that.
Anyone know... May 28 2013, 03:41 PM ThePaintedMan Weird... went and drove it around the block after ... May 28 2013, 05:28 PM carr914 Until it can rev past 6,000, it ain't fixed May 28 2013, 05:38 PM ThePaintedMan Yeah... then I put it back on the ramps to go back... May 28 2013, 06:44 PM vw505 I guess you never had the heads off? I had a crake... May 29 2013, 09:53 AM ThePaintedMan Reaffirmed that the SVDA was installed and timed c... May 29 2013, 07:31 PM r_towle Did you rebuild the engine? May 29 2013, 07:50 PM timothy_nd28 Could plugged or restrictive head vents cause this... May 29 2013, 07:54 PM
r_towle
Could plugged or restrictive head vents cause thi... May 29 2013, 08:04 PM ThePaintedMan Crap, I didn't want this to start getting spre... May 29 2013, 08:07 PM r_towle Hahaha
To late, you started them....
So, what a... May 29 2013, 08:09 PM ThePaintedMan Carb specs:
Weber 40 IDF (early models)
Idles: 50... May 29 2013, 08:11 PM r_towle This is a 1.7 liter motor? May 29 2013, 08:13 PM 904svo Have you check your linkage to make sure both carb... May 29 2013, 08:13 PM r_towle :agree:
I asked in the other thread, post a pic o... May 29 2013, 08:15 PM r_towle With those specs on a 1.7 you are not starved for ... May 29 2013, 08:15 PM ThePaintedMan Ack! So many questions, which really makes me ... May 29 2013, 08:27 PM r_towle Yup, that setup stays synced.
Hmmm
Did someone r... May 29 2013, 08:31 PM ThePaintedMan
Yup, that setup stays synced.
Hmmm
Did someone ... May 29 2013, 08:36 PM r_towle May I suggest a slightly different way of adjustin... May 29 2013, 08:47 PM r_towle Alternate would be to pull the oil pump and see if... May 29 2013, 08:48 PM messix now that it is pulling good until the higher rpm i... May 29 2013, 09:50 PM type2man I think I mentioned this before but have you tried... May 29 2013, 10:38 PM URY914 Check your tire pressure. May 30 2013, 05:01 AM URY914 Clean your windshield. May 30 2013, 05:01 AM URY914 Move your seat all the way back. May 30 2013, 05:02 AM URY914 Do your back-up lights work? May 30 2013, 05:03 AM URY914 Check your heaterbox valves. May 30 2013, 05:03 AM URY914 Change your underwear. May 30 2013, 05:04 AM URY914 Try more brand in your diet. May 30 2013, 05:12 AM ThePaintedMan Don't forget the blinker fluid Paul! May 30 2013, 06:33 AM carr914 How are your Muffler Bearings? May 30 2013, 07:40 AM rhodyguy leak down test. i think i mentioned this earlier. ... May 30 2013, 10:55 AM ThePaintedMan So here's what I did today. New manifold to he... Jun 1 2013, 04:30 PM rhodyguy don't know what to tell ya. what the hell are ... Jun 1 2013, 04:50 PM r_towle If the camshaft was getting smaller, it would not ... Jun 1 2013, 07:18 PM monkeyboy
If the camshaft was getting smaller, it would not... Jun 2 2013, 07:55 AM TurboWalt
If the camshaft was getting smaller, it would no... Jun 10 2013, 07:26 AM ThePaintedMan Adjusted the valves per Rich's instructions, a... Jun 4 2013, 07:46 PM Mblizzard If you really think that the spark is there then I... Jun 4 2013, 08:36 PM r_towle Status? Jun 9 2013, 07:01 AM ThePaintedMan Thanks for checking on me Rich. I went ahead and r... Jun 9 2013, 07:48 PM WLD419
Thanks for checking on me Rich. I went ahead and ... Jun 10 2013, 04:26 PM carr914 4,000 RPM is not High RPM/Load
I still think you ... Jun 10 2013, 04:52 AM ThePaintedMan Thanks for the reply Walt. It's something I... Jun 10 2013, 10:08 AM TurboWalt A broken or weak valve spring could very well be t... Jun 10 2013, 10:31 AM messix He's carbed the needle will bounce on the 2 th... Jun 10 2013, 02:10 PM yeahmag Interesting... I've never used valve stem seal... Jun 10 2013, 04:40 PM ThePaintedMan The generosity in this place never ceases to amaze... Jun 10 2013, 08:49 PM ThePaintedMan :Qarl:
Bill's tool and parts came in today a... Jun 13 2013, 08:03 PM rgalla9146
:Qarl:
Bill's tool and parts came in today ... Jun 13 2013, 09:19 PM edwin If you can pull a plug off and it isn't affect... Jun 14 2013, 07:20 AM old dog
If you can pull a plug off and it isn't affec... Jun 14 2013, 09:58 PM ThePaintedMan Below is a picture of the firing order on the dist... Jun 15 2013, 10:45 AM mepstein Time for a 6. Jun 15 2013, 10:58 AM 904svo Try this remove the cap and turn the rotor my hand... Jun 15 2013, 01:41 PM ThePaintedMan
Try this remove the cap and turn the rotor my han... Jun 15 2013, 02:15 PM 904svo Have you check the resistance of each plug wire? T... Jun 15 2013, 03:34 PM r_towle Move every plug wire on spot clockwise. Jun 15 2013, 03:50 PM timothy_nd28
Move every plug wire on spot clockwise.
:agree: Jun 15 2013, 05:24 PM r_towle And reset the timing by turning the distributor cl... Jun 15 2013, 07:53 PM vw505 Have you got the springs changed out yet? Jun 15 2013, 10:07 PM ThePaintedMan Pulled both springs on the suspected cylinder (#3)... Jun 16 2013, 06:01 PM ThePaintedMan Nevermind. I got it by going back to the basics an... Jun 16 2013, 06:46 PM vw505 Dude, time to pull the heads of and look for crack... Jun 16 2013, 07:12 PM vw505 Or swap out the motor. Jun 16 2013, 07:12 PM r_towle remind me, what distributor is that again?
How ar... Jun 16 2013, 07:16 PM ThePaintedMan Vw505, I'm getting dangerously close to that. ... Jun 16 2013, 07:41 PM r_towle I would suggest that at the point of TDC you have ... Jun 16 2013, 07:50 PM WLD419 Hey George ,
I got nothing except maybe 1 dumb qu... Jun 17 2013, 03:23 AM rhodyguy does your distributor have a notch in the top edge... Jun 17 2013, 08:32 AM ThePaintedMan Rich, I'll give it a shot, but again, I don... Jun 17 2013, 08:36 AM rhodyguy rotor at notch on top distr body (if the body has ... Jun 17 2013, 08:45 AM ThePaintedMan Didn't have time to work on it last night, but... Jun 18 2013, 08:27 AM rhodyguy depends on the indexing and wire placement. if you... Jun 18 2013, 09:08 AM ThePaintedMan
depends on the indexing and wire placement. if yo... Jun 18 2013, 09:25 AM rhodyguy no hard work involved driving a car with 235hp, ac... Jun 18 2013, 10:01 AM r_towle So,
You went off and bought a total chick car, an... Jun 29 2013, 09:12 PM carr914 :rotfl: Jun 30 2013, 04:57 AM rhodyguy richard, the "bought a total chick car" ... Jun 30 2013, 05:48 AM edwin I would assume its aimed at the miata that George ... Jun 30 2013, 06:34 AM ThePaintedMan It was directed at me <_< . FYI, I haven... Jun 30 2013, 07:53 AM ThePaintedMan Didn't get to the MSD today, but I made some p... Jun 30 2013, 07:03 PM r_towle
Didn't get to the MSD today, but I made some ... Jul 1 2013, 12:17 PM carr914 Everytime I turned around it was Raining - I must ... Jun 30 2013, 07:27 PM r_towle So, how's that miata running? Jul 3 2013, 05:44 PM balljoint All that rain has been my fault. I've been rai... Jul 3 2013, 06:06 PM ThePaintedMan I runs quite well Rich. And I even took the top do... Jul 3 2013, 07:34 PM r_towle Just don't let people see you with split ends.... Jul 3 2013, 07:52 PM carr914
Hey Dave, if you're having any real dry spel... Jul 4 2013, 07:03 AM  |
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