Hey all, My 305 (L69 H.O) starts to lose power around 4000RPM and i was wondering if it is due to the Holley or could it be something else?
My Q-Jet was getting 9 Mile per gallon and the Holley gets around 20 Mile per gallon (around town) so you can see why i changed it but now when i shift through the gears it looses power from 4000RPM and up.

The Holley is off a late 60's Camaro (so its old and beaten up) but i have put a kit through it and the 305 has 110,000 miles but has had a hard life (last owner's neglect).

Thanks in advance!

 

What distributor are you using?

 

Chevy V8 HEI Distributor with a Coil on the cap.

 

So as soon as you changed the carb, you had problems? I have a 600 dp on mine and it revs all too quickly to 7k. Maybe the secondaries arent opening, is it vacuum? Did you tune it?

 

it came off a 5L and it went on a 5L so i was hoping i didn't have to tune it, i put the kit through it coz it leaked like crazy but i never realy pushed the car with the old Q-Jet and i have only had a working Tach in it for about a month (i hooked the Holley up the same time i installed the DoubleRoller timing chain). Im thinking of getting the Q-Jet re-jetted but the Q-jet has had the choke riped off so i need to get one of thoes for it aswell.
Yeah vac secondarys.

 

The stock one, or one with mechanical and vacuum advance?

 

It has a vac line going to it.

 

Didnt those motors use a comp controlled distributor? Maybe it was changed. You should pull the cap off of it and see if you have a mechanical advance system (two weights and springs that work centrifugally). If you dont have any of that under there, then its computer controlled and may not be working.
You may want to ditch that carb, they are good carbs but on a simple stock engine it would be a lot easier to put an edelbrock on it. Maintenance is much easier and less to go wrong with it.

 

It is not the stock distributor the cars computer has been gutted, My car has no emissions stuff at all.
It was all riped out and changed when it was converted to RHD.

 

Could be a fuel starvation problem. L69's had in-tank electric fuel pumps - is yours running? If not, it's hard for the engine-mounted mechanical to pull through it - starvation city.

Get a fuel pressure gage on it and observe pressure under the problem conditions.

 

is there any way to check the in tank pump other than droping the tank EG: a removeable panel?
i don't hear a buzzing from the tank so i think it is safe to say she don't work, my mechanical pump has two lines (one from tank the other to the carb) thats it.

Distributor:
http://i21.photobucket.com/albums/b2...7/Image025.jpg
http://i21.photobucket.com/albums/b2...7/Image023.jpg

Carb:
http://i21.photobucket.com/albums/b2...7/Image006.jpg
http://i21.photobucket.com/albums/b2...7/Image019.jpg
sorry the pictures are fuzzy i took them with my phone and excuse the hoses and wires i am going to clean it all up when i get a chance. also if you were wondering yes there is no choke cable connected the car dose not need it to start.

 

There is no access panel to the in-tank electric fuel pump. To get to it, you need to drop the tank. Don't let that intimidate you, it's not as bad as those who advocate cutting a hole in the trunk want you to think.

The choke isn't open all the way. Do you have it held open, or just let it hold itself in place?

If you don't have a fuel return, the electric likely burnt up. Or, it never operated, or is unwired, something like that. Either get it working, or remove it (see sticky about making a pick-up out of an in-tank electric).

 

The choke has a little click when it gets full off or full on and you have to force it to move from that possion (not hard) but it will not close by itself.
ATM it is wide open because im using a drop base air fillter and the base just rests on the choke arm and stops the it from closing.

One more question for ya, once i have modded the in tank pump would it be better to get a high flow electric pump mounted in the engine bay or just stick with the mechanical one for now? Because i am going to have a high HP 327 installed late this year.

 

Either a good engine mounted mechanical, and/or an electric back by the tank. Electric in the engine compartment isn't the best.

 

ok i will have a good look at my options and sort out what im going to do i will look over the carb,dis and fuel pump to see where my problem is.
Thanks to all that have helped.

Oh one thing my VIN is saying i have a L69 but i want to know for shure, Is there any easy to see engine markings to determin that it is a L69?
sry if there is another post explaining this and im just asking what someone else has already asked but i don't have the time to go searching for a post. (im on my work pc)
Thanks again!

 

Check the VIN stamped on the block (on a machined pad in front of the passenger side head under the alternator - you'll probably have to move the alternator to see it). If the VIN says L69, then the engine VIN should match.

What's stamped on the engine is only part of the VIN, by the way. But, the numbers should match what's in the VIN exactly. If they do, it's the L69 engine. If they don't, the engine has been replaced.

There is also a serial number stamped there.

If the numbers aren't on the engine, the block has had the "deck" shaved.

 

Cool thanks, i will look when i get off work.

 

I hope thats not 7k on a stock hydraulic cam block 305 lol!

 

Sure is. I don't try to take it that high, but when the tires break loose, I just cant stop it in time. Its supposed to have a 6k limiter module in the msd box, so its either a 7k (dunno it was used) or my tach is just wrong.