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Edelbrock accelerator pump adjustment question #1300537 09/09/12 06:38 PM 09/09/12 06:38 PM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	Are the accelerator pump nozzles changable on 1405 Edelbrock carbs? I noticed that if I blip the throttle hard enough ( this is on a 1969 Charger 383 4bbl stock squarebore iron intake, 4-speed trans in neutral) I get a stumble. No backfire, just a momentary stumble as the engine revs up. I thought the accelerator pump was running rich so I set the pump lever to it's leanest setting (what I think is the leanest setting- the bottommost hole in the pump lever), and while it seems to have helped, the stumble is still present. I'm trying to figure out how to lean the pump out further- is it possible to change the jet size on the accelerator pump nozzle to something smaller, or does something else need to be rejetted/adjusted? Again-thanks.... David '69 Dodge Charger R/T

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300538 09/09/12 06:55 PM 09/09/12 06:55 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	eyeball the squirt & see if it appears to be of adequate duration with IMMEDIATE tip in. This is with it warmed up so it's not a choke issue correct? float level correct & initial in the ballpark? Any lean stumble issues anywhere else? Reportedly 1405's are jetted on the rich side. Yes the nozzles are interchangeable. EDIT I believe you are too lean rather than too rich & this is a pretty much stone stock 383 right? I'd put the lever closer to the fulcrum and I'm thinking float level/timing/vac leak unless the accel pump itself has a problem Last edited by RapidRobert; 09/09/12 07:07 PM. live every 24 hour block of time like it's your last day on earth

Re: Edelbrock accelerator pump adjustment question [Re: RapidRobert] #1300539 09/09/12 07:07 PM 09/09/12 07:07 PM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	Quote: eyeball the squirt & see if it appears to be of adequate duration with IMMEDIATE tip in. This is with it warmed up so it's not a choke issue correct? float level correct & initial in the ballpark? Any lean stumble issues anywhere else? Reportedly 1405's are jetted on the rich side. Yes the nozzles are interchangeable Right- this is completely warmed up- my choke is currently wired open so that's not coming into play, either. I had rebuilt/cleaned the carb out about a year ago and had checked the float level/drop and blew out the passageways with carb cleaner. It idles fine at 800rpm- I tried to get it to idle at 750 and it fights me on that though. And yes those 1405s are jetted rich- I had to rejet this down 2 jet sizes on primary/secondaries (and switched metering rods, too) and while the plugs aren't black anymore, I still think it's running a bit on the rich side. I haven't checked the pump stream so I'll do so to make sure there's no delay in the stream. '69 Dodge Charger R/T

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300540 09/09/12 07:27 PM 09/09/12 07:27 PM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	I'm going to amend the symptoms here - actually I did get it to backfire once or twice. It didn't do it all the time though. There was still some stumbling though- as if the engine was running rough at a constant RPM. But it wasn't like it had a flat-spot then suddenly picked up RPM though. It immediately increased it's speed but it was sounding rough when it was doing it. I'm going to change the accel pump level setting back to it's midpoint, but it'll still leave me with the rough acceleration. '69 Dodge Charger R/T

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300541 09/10/12 07:46 AM 09/10/12 07:46 AM
Joined: May 2003 Posts: 15,487 Florida S scratchnfotraction I Live Here
scratchnfotraction I Live Here S Joined: May 2003 Posts: 15,487 Florida	Quote: Are the accelerator pump nozzles changable on 1405 Edelbrock carbs? yes,so is the step up springs,needles/jets. most 1405s I have run had the accel pump rod in the middle of the 3 holes. they are also know to be a little lean depending on what # carb you have. older 750 has a casting flaw from factory and are poop. 1405s 600cfm are pretty good for street duty IMHO. PM sent to you.

Re: Edelbrock accelerator pump adjustment question [Re: scratchnfotraction] #1300542 09/10/12 10:37 AM 09/10/12 10:37 AM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	Quote: Quote: Are the accelerator pump nozzles changable on 1405 Edelbrock carbs? yes,so is the step up springs,needles/jets. most 1405s I have run had the accel pump rod in the middle of the 3 holes. they are also know to be a little lean depending on what # carb you have. older 750 has a casting flaw from factory and are poop. 1405s 600cfm are pretty good for street duty IMHO. PM sent to you. Well my Edelbrock is about 3 years old- I heard of that casting issue but I think mine's new enough where that doesn't apply? I also got to thinking- since I'm experiencing more of a stuttering than a flat spot I'm beginning to suspect the ignition system- particularly the spark plug wires. It idles just fine but when you rev it up I'm wondering if I have a bad wire that's not allowing one cylinder to fire reliably.... '69 Dodge Charger R/T

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300543 09/10/12 02:16 PM 09/10/12 02:16 PM
Joined: Apr 2012 Posts: 18,880 - R RSNOMO Moparts Torchbearer
RSNOMO Moparts Torchbearer R Joined: Apr 2012 Posts: 18,880 -	I'd make sure the secondary ignition system is good all the way to the plugs before diving into the carb again...

Re: Edelbrock accelerator pump adjustment question [Re: RSNOMO] #1300544 09/10/12 02:30 PM 09/10/12 02:30 PM
Joined: Jan 2003 Posts: 42,714 Spokane Washington ScottSmith_Harms Mr Wizzard
ScottSmith_Harms Mr Wizzard Joined: Jan 2003 Posts: 42,714 Spokane Washington	I agree, with the occasional backfire It sounds more like an ignition issue.

Re: Edelbrock accelerator pump adjustment question [Re: ScottSmith_Harms] #1300545 09/10/12 11:00 PM 09/10/12 11:00 PM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	Yea I'm beginning to suspect the ignition, too. The behavior of the engine as it accellerates doesn't seem to be fuel related (the backfire and the fact that it's more of a stutter than a flat spot) I suspect that my spark plug wires might be bad (the spark plugs themselves are good, supposedly - I replaced them just last weekend) so I'm going to check them for arcing and continuity later this week. The cap is old, too- I'll check the inside for signs of arcing. Will post my findings of course.... '69 Dodge Charger R/T

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300546 09/11/12 12:43 AM 09/11/12 12:43 AM
Joined: Aug 2003 Posts: 43,096 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,096 Bend,OR USA	Makle sure the check valve is in place under the accelerator squirter in the carb. Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Re: Edelbrock accelerator pump adjustment question [Re: Cab_Burge] #1300547 09/11/12 04:08 PM 09/11/12 04:08 PM
Joined: Jan 2003 Posts: 5,270 Missouri M MY340 master
MY340 master M Joined: Jan 2003 Posts: 5,270 Missouri	Make sure you're running enough intial timing too. It can cause a stumble/hesitation that many take for a carb problem. You shouldn't be having problems with a 3 yr old carb.... 1970 FE5 Duster 360/904/3.91's SOLD 1973 TB3 SpaceDuster 340/4spd/4.10's SOLD Moparless for now but when the opportunity is right I'll have another one.

Re: Edelbrock accelerator pump adjustment question [Re: MY340] #1300548 09/11/12 06:59 PM 09/11/12 06:59 PM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	Quote: Make sure you're running enough intial timing too. It can cause a stumble/hesitation that many take for a carb problem. You shouldn't be having problems with a 3 yr old carb.... I'm running 12deg BTC at idle (vacuum disconnected)- I would think that's enuf. My timing's all in at around 35 deg @ (I think) 2500rpm. I'll check on the pump ball too but like you said, this carb isn't that old- and hasn't seen much if any use. But I did have it apart once and it's always possible I forgot to put it in when I reassembled it. '69 Dodge Charger R/T

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300549 09/11/12 08:05 PM 09/11/12 08:05 PM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	I pulled the distributor cap and.... well, I'm not sure what to make of this (note the bevels worn out at the bases of each wire terminal where the rotor's been striking them): I also found some fine, powered metal flakes dusted all over the inside of the cap (which by the way doesn't look like there's been any arcing): For grins I tried to line up the rotor (using the worn out spot where the rotor pivots against the coil wire contact as a guide) to see how close it was getting to the plug wire terminals, and... well it looks like a pretty big gap- about a 1/8" from the tip of the rotor going across to the face on the notch of the terminal: Any ideas? I've seen caps where the arc would jump straight across to the opposide side of the notch and I've never seen this kind of wear before on the terminals. And I'm not sure if there's supposed to be that large a gap between the rotor and the wire terminals. But I might be wrong on this of course. '69 Dodge Charger R/T

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300550 09/11/12 08:35 PM 09/11/12 08:35 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Might get a good ribbed cap also with brass terminals. NAPA offers an Echlin MO 3000 rotor with a .060" longer blade, $8.xx. Could be a stackup of tolerances and I'd remove the dist & drive out the lower roll pin and remove the plastic collar and add 1/2" ID flat washers & get your end play to .005" then add the collar & drive in the roll pin. www.speedwaymotors.com has a cheap kit or your hardware store. Might drill a rectangle or 2 in the side of your cap & mockup & check your actual clearances and I would drill a 3/8" hole in the top flat of the cap 2/3 of the way between the center terminal and #1 terminal & check rotor phasing with your timing light at idle and above idle (ported I'm assuming) vac adv will shift it CW on a BB and CCW on a SB from the no vacuum position live every 24 hour block of time like it's your last day on earth

Re: Edelbrock accelerator pump adjustment question [Re: RapidRobert] #1300551 09/11/12 09:13 PM 09/11/12 09:13 PM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	Quote: Might get a good ribbed cap also with brass terminals. NAPA offers an Echlin MO 3000 rotor with a .060" longer blade, $8.xx. Could be a stackup of tolerances and I'd remove the dist & drive out the lower roll pin and remove the plastic collar and add 1/2" ID flat washers & get your end play to .005" then add the collar & drive in the roll pin. www.speedwaymotors.com has a cheap kit or your hardware store. Might drill a rectangle or 2 in the side of your cap & mockup & check your actual clearances and I would drill a 3/8" hole in the top flat of the cap 2/3 of the way between the center terminal and #1 terminal & check rotor phasing with your timing light at idle and above idle (ported I'm assuming) vac adv will shift it CW on a BB and CCW on a SB from the no vacuum position Thanks Robert- I'll see if I can find those at NAPA. On the washer though- wouldn't I want something like a Grade 5/8 for that? I'll check the end play on the distributor and try to shim that down to .005" (I seem to think/remember that it's certainly got a lot more play than that- but I didn't think it was bad enough where the rotor would hit the terminals) '69 Dodge Charger R/T

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300552 09/11/12 09:22 PM 09/11/12 09:22 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Yes get the best grade washers you can live every 24 hour block of time like it's your last day on earth

Re: Edelbrock accelerator pump adjustment question [Re: RapidRobert] #1300553 09/15/12 05:33 PM 09/15/12 05:33 PM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	Well I got some washers, pulled the distributor and when I started to check on the play I noticed something odd..... Holding onto the bottom of the drive shaft and checking the end play I found that it had hardly any end play at all. But when I grasped the rotor end of the shaft and wiggled it, it definately had play. But when I did this and watched the drive end of the shaft, the drive end didn't budge at all.... So I have wear somewhere inside the distributor itself. Can this be repaired or am I looking at getting a rebuilt distributor (or sending this out to be rebuilt-it's the original distributor)? I did get a dial gauge on it and measured the play - it came to about .055". Obviously enough to send the rotor into the top of the cap :/ Any Ideas? David P.S. It's a Chrysler distributor- and while the FSM shows a exploded diagram of the insides, the FSM doesn't say anything about disassembling/repairing the shaft/centrifugal advance assembly... Last edited by David_Trimble; 09/15/12 05:46 PM. '69 Dodge Charger R/T

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300554 09/15/12 07:31 PM 09/15/12 07:31 PM
Joined: Nov 2011 Posts: 653 montana P pjc360 mopar
pjc360 mopar P Joined: Nov 2011 Posts: 653 montana	pretty sure you can replace the bushing in the distributer and that play wouldnt be there anymore. Also i would try more initial timing if i were you, bump it up to 14 or 16 degrees. My small block likes 14 degrees initial, i'm sure that 383 would appriciate a little more initial timing.

Re: Edelbrock accelerator pump adjustment question [Re: David_Trimble] #1300555 09/15/12 08:06 PM 09/15/12 08:06 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: Any Ideas? Look down in the center top below the rotor and locate the clip. You'll see 2 vertical legs. Spread them a bit wider several times with your narrowest pair of needle nose pliers. You wont be able to expand them much. then grab either of the vertical legs and whip it around and up and out in the direction that expands the clip all in one motion. You'll need a thin brass washer of the right dimentions (Ace hardware has a good selection) and use it to reduce the axial play then set the clip back down in there & compress the 2 vertical legs. You dont have much room to compress them much but if some of the horizontle circle of the clip is under the nub it will hold it in place. Try compressing it a half dozen times till you make some progress. live every 24 hour block of time like it's your last day on earth

Re: Edelbrock accelerator pump adjustment question [Re: RapidRobert] #1300556 09/15/12 08:35 PM 09/15/12 08:35 PM
Joined: Jan 2003 Posts: 738 OK D David_Trimble OP super stock
David_Trimble OP super stock D Joined: Jan 2003 Posts: 738 OK	Quote: Look down in the center top below the rotor and locate the clip. You'll see 2 vertical legs. Spread them a bit wider several times with your narrowest pair of needle nose pliers. You wont be able to expand them much. then grab either of the vertical legs and whip it around and up and out in the direction that expands the clip all in one motion. You'll need a thin brass washer of the right dimentions (Ace hardware has a good selection) and use it to reduce the axial play then set the clip back down in there & compress the 2 vertical legs. You dont have much room to compress them much but if some of the horizontle circle of the clip is under the nub it will hold it in place. Try compressing it a half dozen times till you make some progress. Found the clip- it was hiding under the felt 'plug'. I got it apart now. I think I see what happened that caused this too. The distributor was recurved as I found machining marks on the advance side of the drive shaft. And when they machined the surface facing the centrifugal weights it looks like they did a little grinding, which ground down the face that rests on the plastic spacer that goes over the shaft between the weights for the advance to rest on. In doing so they shortened the distance beween the point where it rests and the groove where the clip goes. So I need a washer (and you said brass, I don't need a grade 5/8 washer?) to fit down under the clip goes, correct- To keep the advance shaft from riding up? Or would I need a washer to compensate for what had been ground off? I can post pics if it'll help... '69 Dodge Charger R/T

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