Timing

[frostbite77]

Hi, I am a fairly new bronco owner. Used to have mustangs, but sold my 69 mach 1 for this 77 bronco. I got it running, changed the plug wires and plugs, cleaned out the fuel lines, put in a new carb kit and cleaned out all the ports, set the timing, but can't get the vaccum secondaries to open under load. The intake and carb have been change to 4bl from 2bl. A stock 302 intake was used and a truck avenger holey carb. I advanced the timing from 8 degrees to 12. Anyone know what I am doing wrong. It backfires and has no power nor will the secondaries open.

 

[Bully Bob]

Hi Frostbite...welcome.,

Hmmmm, even I have put plug wires on wrong..... /emoticons/[email protected] 2x" width="20" height="20" />

Gonna need more info...,

like... "It backfires and has no power"

Is this at idle., off idle...?

Did you consider a compression test..?

 

[frostbite77]

I checked the plug wires and firing order. They are correct. Compression is good and it idles like a dream as well as starting well. When you go to step on the gas it just dies and will barely move the truck along. I cant even get the thing back up my driveway which is about a 35 degree incline.

 

[frostbite77]

I does start to backfire and has no power once you put it in gear and step on the gas.

 

[frostbite77]

I did advance the timing to 12 degrees up from 8 like it came stock, but it also has been converted to a 4bl intake and carb. Any ideas?

 

[Bully Bob]

I'm not fimular with that carb. but., idles good then stumbles off idle then it sounds like some dirty main jets....

The secondaries would never open in that condition.

-OR- there's a chance there's something a'miss in the dizzy or the timing chain.

Does the timing mark jump 'round or does it remain steady, while using timing light..?

 

[bigbluebronc]

Hi, I am a fairly new bronco owner. Used to have mustangs, but sold my 69 mach 1 for this 77 bronco. I got it running, changed the plug wires and plugs, cleaned out the fuel lines, put in a new carb kit and cleaned out all the ports, set the timing, but can't get the vaccum secondaries to open under load. The intake and carb have been change to 4bl from 2bl. A stock 302 intake was used and a truck avenger holey carb. I advanced the timing from 8 degrees to 12. Anyone know what I am doing wrong. It backfires and has no power nor will the secondaries open.

Did you drop the tanks and clean them out, I have found the tanks too be the problem in lots of old fords, My bronco tank gave me problems for a year before I figured it out and my old mustang wanted a new tank even though it had a new one two years ago, red sludge ran out like someone filled them with bleach... the fuel pump might be jacked up with sludge too.. if the 77 was not driven for a while that could plauge you for along time

BBBCall Holley with the truck avenger carb they had bad metering blocks that where a bad casting and coroded after 4 months I had that problem and they sent me a newer one the secondarys only open under load

BBB

 

[andre]

ok may be i am dumb

dont 4 barel intake bigger port then 2 barel was head change ?? or machine

may have some leak in intake gasket bad carb or carb gasket bacfire can be chain or dist not on mark bad coil ext

was chain remove or change if not

check if dist on mark

if yes do compression test

that tell you if engine ok

do that then come back

that where id start

what engine in there org or later one

like taking 289 and puting 302 fi intake will fit but run like crap

take all info post on here take you're time to checl all posibility

good luck

 

[Bully Bob]

Hi Andre.., how's things up north..??

Naw.., if you look., he changed the intake manifold as well...to accommodate the bigger carb.

"Ditto" on the rest of your suggestions.... /emoticons/[email protected] 2x" width="20" height="20" />

 

[bigbluebronc]

Did you drop the tanks and clean them out, I have found the tanks too be the problem in lots of old fords, My bronco tank gave me problems for a year before I figured it out and my old mustang wanted a new tank even though it had a new one two years ago, red sludge ran out like someone filled them with bleach... the fuel pump might be jacked up with sludge too.. if the 77 was not driven for a while that could plauge you for along time

BBBCall Holley with the truck avenger carb they had bad metering blocks that where a bad casting and coroded after 4 months I had that problem and they sent me a newer one the secondarys only open under load

BBB

Secondaries only open under load that means driving and even better up a hill, Call holley with carb number another friend just had the same problem with the older truck avenger carb it coroded the metering blocks, no fuel no go, if its bad you get a new carb for freeeeeeeeeeee !!!!

BBB

 

[andre]

yes i know but did he check / head port and intake port may not be same size that my "Q"

and was it runing before change was done because it he remove dist cauld be just that

that wy first i check dist to crank mark see if it macht

 

[frostbite77]

This is awsome! Thanks to all of you guys for your input. I tried all that was suggested. I had dropped both gas tanks and cleaned them out. The exudate looked like molasses coming out of the tanks. That was prior to the carb issue though. The problem ended up being as bronco **** and bully bob described, coroded metering blocks and dirty main jets. Thanks gentlemen for the help I appreciate it. Not many people that actually still work on carbed engines anymore. I will try to post some pictures as I restore this baby over the next couple of years.