[hcompton]

Unhook and plug vacum advance and see if it smooths out will be down on power but should run smooth if its knocking cause of too much timing.

The kit you need for stock hei is a dizzy recurve kit they sell at summit and jegs. Get one with vacuma advance lockout and mechanical advance lockout. If totally stock dizzy get a kit with a coil and modual as well.

You can do a search for the pics of the install. Everything is easy to do and you can find directions on the forum on how to install.

What about fuel filter and fuel level in float bowls. I really do think its fuel but kinda sounds like your timing is set wrong as well.

You can buy a new dizzy with all this stuff installed but tis always needs tuning and they dont reallly advertise which kit comes with which options so i always use recurved factory one.

[89k1500]

Thanks for the links and other information guys! Looks like I have a lot of reading to do. I think i'll buy a limiter plate and the crane advance kit and try and dial in the timing.

"If you slowly accelerate and shift into 3rd gear,coast for awhile the hammer it,does it instantly fall down or is it ok for a few seconds?" I will have to try this and get back to you!

I will more than likely switch back to the electric pump also just to eliminate the fuel pump as the problem.

Fuel filter was one of the first things to get changed. =)

[hcompton]

Originally Posted by 89k1500

Thanks for the links and other information guys! Looks like I have a lot of reading to do. I think i'll buy a limiter plate and the crane advance kit and try and dial in the timing.

"If you slowly accelerate and shift into 3rd gear,coast for awhile the hammer it,does it instantly fall down or is it ok for a few seconds?" I will have to try this and get back to you!

I will more than likely switch back to the electric pump also just to eliminate the fuel pump as the problem.

Fuel filter was one of the first things to get changed. =)

Sounds like your on the right track.

Like vinnie said. If you can coast for a few second and it hits hard for a few second then its runiing the float bowls dry and needs more fuel pump. this is a common issue and may just be a slow fuel system with small lines or pump.

You said you jetted the carb richer did this help the issue or make it worse/better. If its ignition knocking, jetting up should have some small efects on the problem.

You can buy a high volume mechanical fuel pump. Edelbrock sells a chrome one but you can buy one for cheap at any good auto parts store. Try to avoid the high pressure one it is more of an issue to install. Since you need a regulator to run it. And cheap regulator can lead to the same problem you are having. Since they are too small to flow enough fuel. 6 psi works great for most carb setups. 7 will flood the carb 5 may run dry at wot.

If you can eliminate fuel as an issue it would really help narrow down the problem.

[89k1500]

The regulator that I am running now is a mallory 3 port competion regultor(return style) PN 4309. I'm going to hook up the electric pump when I get a chance and see if that cures some of my issues. The more I read on setting timing and what-not the more I think I need to address that as well.

Thanks again for the links and info! If you guys have any other helpful links on this stuff feel free to post em. I have no problem reading and I am new to the carburated world, and my brother works weird hours so it looks like if this truck is gunna get dialed in, its going to take effort on my part too. =)

[hcompton]

Originally Posted by 89k1500

The regulator that I am running now is a mallory 3 port competion regultor(return style) PN 4309. I'm going to hook up the electric pump when I get a chance and see if that cures some of my issues. The more I read on setting timing and what-not the more I think I need to address that as well.

Thanks again for the links and info! If you guys have any other helpful links on this stuff feel free to post em. I have no problem reading and I am new to the carburated world, and my brother works weird hours so it looks like if this truck is gunna get dialed in, its going to take effort on my part too. =)

Yep doing the electric pump will help resolve the fuel issue. If adding richer jets and tuning the needles and accelerator pump and using the electric pump didnt do the trick then you can rule out fuel and move on to timing quickly. Its easy to hook up a bosh relay with a switch to run the pump. You can also run it off the ignition key power on but for testing a switch will do the trick and let you rule out the fuel pump once and for all.

This kit is from pertronix and may not be high quaility but will do the trick.
HEI Distributor Accessories

The kit does not appear to have the mechanical advance lockout/limit plate. You may need to get that seperate. Also buying the modual and coil with cap rotor rules out a lot of things all at once.

Use the lightest springs to allow all mech advance to be in at 2500-3000 rpm. Limit mechanical adavance to 10 degrees or so which is about the last position on the limit plate.

Set the vacum can to operate at the vacum you have at off idle. Maybe someone else can help with how to set vacum can actuator. But as for the lockpit make sure its set to give no more than about 11 degrees.

Then set initial timing at 15- 30 depending on how the rest of the distributer was setup. I usally time them with a timing light and ear. Just listen tell it sounds its meanest reving it up in park from under the hood and make sure that is not a crazy high setting then back it off a few degrees and drive with a wrench and adjust as i go. As much advance as you can get with out it knocking or breaking up.

Now with all that said a dyno tune is in order if you have the cash. Because you can damage the engine with too much timing and for it to run its best you want to be close to the limit. It may be best to have it tuned with sniffers and dyno to gurantee no damage results from the tunng process.

Once all this is done you will have checked replaced or repaired the: distributor, including cap rotor mod coil wires and plugs (oh yeah replace the plugs with colder ones might be needed) and you can also rule out fuel pump and main jets since they were upped to larger size already. That covers alot of ground and all the simple causes for your problem.


Hope this helps.

[cobalt327]

Cam has 226 int./234 exh. @ 0.050" lift and needs no where near 26 degrees initial. Start around 16-18 degrees initial and work up from there.

Generally it is better to get the timing worked out, then go on to carburetion- as long as it's running well enough to set the mechanical (should be all in by about 3K rpm).

[89k1500]

Well I finaly got some time and messed with the fuel system. Hooked the electric pump up and now I have a solid 6psi. Now when I drive it it still backfires in third and higher gears, but it has a LOT more power. I havent messed with the carb settings since changing the pump(it was 30 degrees outside) and I still think the timing is off, but so far there is marked improvement!

[hcompton]

Originally Posted by 89k1500

Well I finaly got some time and messed with the fuel system. Hooked the electric pump up and now I have a solid 6psi. Now when I drive it it still backfires in third and higher gears, but it has a LOT more power. I havent messed with the carb settings since changing the pump(it was 30 degrees outside) and I still think the timing is off, but so far there is marked improvement!

Good to hear at least your on the right track. Maybe try 7psi and see of that floods on sharp turns or braking if not it should be ok at that psi. Now hopefully it will respond correctly to jetting changes and allow its self to be tuned properly.

I like to tune on a cold day but not 30 degrees. LOL

Now i would think its time to look at the plugs and see how its running or hook up some type pf lean rich guage even without wide band a regular o2 sensor really helps tune somtimes. But detonation should show up on the plugs. Also should be able to tune it out by setting the timing at 10 degrees and just test drive to see if it cleans up a little if not its surely carb realted. Unless the distributer is completely out of whack with mech advance worn out that should clean up the knocking a little. Maybe even a little less for short trip to see if its ignition problem. bad coil and bad modual are still likely an issue. Its never certain they are good unless they are new and tested.

[89k1500]

I foregot that I had put a distriburator on it from e-bay. Not sure if that makes it better or worse

SBC BBC Chevy 65K Red Hei Distributor 6501 R | eBay

not sure how good of quality it is. It was in another motor and that one didn't have any problems other than being tired.

What am I looking for on the plugs? I had em out today and they were kinda black. They were new when we put the motor together.

are you thinking I have too much timing and that is why I am setting it a 10deg?

[cobalt327]

Depending on the distributor that was on it, that could have made all- or none- of the difference. That's why it's a better idea to make ONE change at a time, so you know what helps and what doesn't.

In any event if it's running better, something caused it and that's a step in the right direction.

[89k1500]

oops, I was kinda unclear. I ment when we put the motor together we put the ebay distriburator in it. Its not a recent thing I have done while trying to troubleshoot the problem.

[hcompton]

Originally Posted by 89k1500

I foregot that I had put a distriburator on it from e-bay. Not sure if that makes it better or worse

SBC BBC Chevy 65K Red Hei Distributor 6501 R | eBay

not sure how good of quality it is. It was in another motor and that one didn't have any problems other than being tired.

What am I looking for on the plugs? I had em out today and they were kinda black. They were new when we put the motor together.

are you thinking I have too much timing and that is why I am setting it a 10deg?

Well a new distributer makes a difference. Did it come with any extra parts. I suggest moving the timing cause it is the next easiest thing to try. But this is much less likely a problem with a performance distributer. Stock dizzy has much more timing curve in factory tune. Usally they tune the performance models a little different. You should be able to find specs on it.

Heavy detonation will show up as spotting on the plugs. Black can be because the engine is missing or running rich. You almost need clean plugs to see how the engine is running. Do you have a spark plug cleaner or a way to clean them quickly. Maybe buy a few new ones and use them one at a time and see how they look.

Be sure to clean the plugs they may be fouled after missing for so long.

Do you have the edelbrock tuning kit or did you just buy jets?

[lg1969]

What you get is lean backfire. Your 1st and 2nd gear may be fine, But it may bog on 3rd gear cause by large primary. Your intention on your 4X4 is to produce torque not RPM. Use a 600 to 650 CFM carburetor. 750 is too much. Also increase the advance weight on the dist. Using a Qjet would be a better way to go.

[hcompton]

Originally Posted by lg1969

What you get is lean backfire. Your 1st and 2nd gear may be fine, But it may bog on 3rd gear cause by large primary. Your intention on your 4X4 is to produce torque not RPM. Use a 600 to 650 CFM carburetor. 750 is too much. Also increase the advance weight on the dist.

Lean back fire is very possible but he has already went up a step on the mains so it should atleast be drivable. Maybe not making max power but running.

At this point need to read the plugs and see if its lean or rich.

750 should be ok for most apps. 600 650 may make a few ponies moe down low but the 750 should run ok.

Might just be plugs at this point not sure since the fuel pressure change helped. Cleaning the plug may sort it out.

If you have another edelbrock around that you can swap and try i say try it but most ppl dont have an extra hp carb laying around the garage. It is certainly possible to get a bad carb from the factory. Another user on the forum recently had that happen to him and holley replaced it for fre and it resolved the issue. Unfortunely most manufactures will at least want to run over a testing proceedure and try to get things smoothed out over the phone.

A call to edelbrock might not be a bad idea. They have good techs on hand usally that can go over the install and find any gottchas since they deal with the carb every day might be able to fix it faster than any other testing.

[lg1969]

Increasing the jets will not get rid of lean bog. Because not producing enough RPM to make the jets work. He is working mainly on idle circuit until he have enough RPM for the main jets to come into play. The smaller the primary the more responsive the primary jets come in.