Edelbrock 1406 Tuning for Dummies

[aaron6920]

Well over the weekend I replaced a shift seal and o ring on my C4. I also put a shift kit in the valve body while it was out. The roads are still covered in sand and grime but I wanted to see if the Bronco at least shifted and drove.

I put a 1406 Edelbrock carb and 289 intake on the bronco over the winter. It starts and idles fine, but when I was driving around the driveway starting from a stop the carb would kill. How do I start with this carb tuning? I bought the jet kit with the carb I just havent worked in it yet because of not driving it in winter.

I have not much experience in tuning carbs, what should I do?

 

[broncnaz]

Do you have the instructions for the carb they will pretty much walk you through most issues. If you dont have them go to edlebrocks website and down load them.
A little better description of the actual problem would help as well like exactly when your engine dies. ie, trying to take off or it just died while putting around? Did it die instantly or sputter.
Your issue may not even be carb related but we wont know until you give us better info.

 

[aaron6920]

Do you have the instructions for the carb they will pretty much walk you through most issues. If you dont have them go to edlebrocks website and down load them.
A little better description of the actual problem would help as well like exactly when your engine dies. ie, trying to take off or it just died while putting around? Did it die instantly or sputter.
Your issue may not even be carb related but we wont know until you give us better info.

I will see if I can find the directions on the site. I didnt think it came with other instructions. If I am stopped and hit the gas with any force the truck dies. I need to "feather" the throttle to not kill on start up. I can rev the engine when parked with not much hesitation. I havent pulled any plugs maybe I could start there. I was just curious what might be the best adjustment to start?

 

[Crawdad]

I will see if I can find the directions on the site. I didnt think it came with other instructions. If I am stopped and hit the gas with any force the truck dies. I need to "feather" the throttle to not kill on start up. I can rev the engine when parked with not much hesitation. I havent pulled any plugs maybe I could start there. I was just curious what might be the best adjustment to start?

Keep this thread up b/c I have a 1403 (500 cfm) that I plan to install in the coming weekends! Did you have to buy any extra for the carb install? Any new linkage for automatic or do u have manual tranny? Post some pics if u have them! THX!!!!!

 

[broncnaz]

Pulling the plugs wont tell you a lot at this point once you get it running correctly then you can pull the plugs and decide what fine tuning is needed. I usaully find that 1406's are a little on the rich side for a 302 but it usually doesnt cause any driveability issues. but once you lean it out you should get better mileage and maybe even better power.

Sounds like the accelerator pump is not working. With the engine off look down the throat of the carb and open the throttle do you see fuel squirt into the carb as soon as the throttle is moved? If not then your accelerator pump is not working. If you do see fuel squirt then you have some other issue.
If the accelerator pump is not working or it only squirts a little and not right when you move the throttle then you eityher need to adjust the pump linkage or I would suspect that the float level may be to low and no gas is getting into the pump. Once you download the instructions you will have the info for adjustment of the acclerator pump aand how to set float levels ect.

 

[aaron6920]

Keep this thread up b/c I have a 1403 (500 cfm) that I plan to install in the coming weekends! Did you have to buy any extra for the carb install? Any new linkage for automatic or do u have manual tranny? Post some pics if u have them! THX!!!!!

Hey Crawdad, I bought the linkage kit with it also. It is for the C4 kickdown rod. If you have manual this would not be necessary. The throttle hooks up ok it is at a slight angle. I think I should have bought the the 1403, 500 cfm seems good for these trucks.

 

[aaron6920]

Pulling the plugs wont tell you a lot at this point once you get it running correctly then you can pull the plugs and decide what fine tuning is needed. I usaully find that 1406's are a little on the rich side for a 302 but it usually doesnt cause any driveability issues. but once you lean it out you should get better mileage and maybe even better power.

Sounds like the accelerator pump is not working. With the engine off look down the throat of the carb and open the throttle do you see fuel squirt into the carb as soon as the throttle is moved? If not then your accelerator pump is not working. If you do see fuel squirt then you have some other issue.
If the accelerator pump is not working or it only squirts a little and not right when you move the throttle then you eityher need to adjust the pump linkage or I would suspect that the float level may be to low and no gas is getting into the pump. Once you download the instructions you will have the info for adjustment of the acclerator pump aand how to set float levels ect.

Thanks for the tips, I will check this out tonight and see if the pump is working properly.

 

[Airmapper]

Was the Edelbrock new or was it used? I have a 1406 on my '70, and the PO had it all out of whack, so I got a rebuild kit and followed the instructions as best as I could. Once I got done I bolted it back on and without touching anything it's now running great as far as I've been able to test it.

Link to instructions, you can at least use it to check the floats and make sure everything is set right even if you don't replace everything. LINK

 

[aaron6920]

Was the Edelbrock new or was it used? I have a 1406 on my '70, and the PO had it all out of whack, so I got a rebuild kit and followed the instructions as best as I could. Once I got done I bolted it back on and without touching anything it's now running great as far as I've been able to test it.

Link to instructions, you can at least use it to check the floats and make sure everything is set right even if you don't replace everything. LINK

Thanks Airmapper, it is the Edelbrock refurb. carb. It still should be set ok I would think. Good info on that link.

 

[aaron6920]

Airmapper- after your truck sits a couple weeks, do you have to pump the carb a lot? It seems like I have to crank a little and pump 8 or 9 times before it will start.

All my previous carb cars would be two pumps and go. Just wondering if that was common.

 

[TBS-POPS]

Did you check your accelerator pump?? if it is working then you need to look for vacume leaks.
I run a 1406 and they will boil the gas out after running and the next start after a couple of days would take alot of cranking and pumping to start. installing a 1" plastic insulator plate under the carb cures the problem .

 

[Airmapper]

Airmapper- after your truck sits a couple weeks, do you have to pump the carb a lot? It seems like I have to crank a little and pump 8 or 9 times before it will start.

All my previous carb cars would be two pumps and go. Just wondering if that was common.

I'll have to let you know in a week or so, it wasn't running good when I bought it so I took off the carb to rebuild (guys here suggested that) and last weekend was the first time I've been able to drive it any. To me 8-9 pumps doesn't sound too bad for a cold start, so long as it will start, but I'm not too experienced with this myself.

What kind of choke do you have? That could cause difficult starting. Mine has electric, and it seems to work but I'm not too fond of it since I can't tell what it's doing. If it is electric, I've heard they are touchy about voltage. I hook mine up to the battery directly to test, but for permanent hookup I hear you need a solid 12v however you hook it up.

 

[broncnaz]

Low Float level is the main culprit of hard starts with edelbrocks. Usually over time and rough roads the float setting changes and the fuel level lowers to the point that gas wont refill the accelerator pump well. making for harder starts. Also fuel evaporation due to sitting or heat soak can also cause issues with hard starting. Edelbrock/Weber's accelerator pump design is such that this causes issues. but otherwise its a decent carb for the street.

 

[gravelrunner69]

I've been running a 1405 for 14 years and love it I had the same issue as TBS-POPS,and the spacer did the trick. after putting it on and basic adjustments I have'nt had to touch it,but I'am going to put BC headers and 2into1 exhaust on this spring so I'am sure I'am going to have to check it after that, also thanks for the link

 

[aaron6920]

Ok, I am still having trouble getting this carb to run right. I had a vacuum leak around the base I discovered and replaced the gasket and now that is fixed. I also set the float to 7/16 per the instruction manual. That was really off from Edelbrock.

I replaced the spark plugs they were solid black and I thought it may have been due to the float being way off and dumping fuel. Today I ran it and the idle is good and partial throttle. When I put full throttle from idle the carb backfires and puffs. It must still be running way too rich, I have the tune kit but am a little confused from the manual what I need to change.

 

[Scott 756]

When I was shopping for a replacement for my Holley, Tim helped me fine tune my 500cfm Edelbrock 1403. I'm just guessing but, if you have a 600 cfm carb, could it be too much carb for the 302? I also have a vintage 289 intake with a 1" spacer.

 

[broncnaz]

I'd say now that maybe you have to much igintion timing if its back firing through the carb. Usually jetting wont cause back fires. Most carbs are fairly close in jetting for most engines your tuning kit is just used to dial it in to get the best performance/ effcieceny.

 

[Bronco Maniac]

When I bought my carb it came with a CD explaining the carb and adjustments. You can do a search on You Tube for Edelbrock and find the videos for this carb from the CD. There are several different parts on You Tube for the video.

 

[aaron6920]

When I was shopping for a replacement for my Holley, Tim helped me fine tune my 500cfm Edelbrock 1403. I'm just guessing but, if you have a 600 cfm carb, could it be too much carb for the 302? I also have a vintage 289 intake with a 1" spacer.

In hindsight I might have looked at the 500 cfm. I think I have a timing issue currently I guess I better get the timing light out....

 

[aaron6920]

When I bought my carb it came with a CD explaining the carb and adjustments. You can do a search on You Tube for Edelbrock and find the videos for this carb from the CD. There are several different parts on You Tube for the video.

I will look for that thanks, mine only came with the booklet.