Chevy 350 no power HELP!!

30295 Views 16 Replies 8 Participants Last post by Smokedmaxxx, Sep 14, 2012

Smokedmaxxx

Discussion Starter · Sep 13, 2012

Whats up fellas, well this is the story on my nova
Bought from a widow, car sat in garage for 8 yrs
350 (71" 4bolt main, 4bbl) w/ 305 Heads (4416) , Edelbrock 1407, weiand a xcelerator intake manifold, summit 1103 camshaft, stock dual exhaust exiting behind rear wheels, headers, HEI distributor, Rear Gears not sure ( also never removed the oil that I bought it with, someone told me not to mess with that since the old oil has been in their without change so long that it could damage it with new oil??) HELP

Timing @ 8 degrees, total timing @ 32 idle @ 550 running VR-1 10-30 oil

Problem- Accelerator Pedal feels Hard , also I feel like it has no Power (like it has such a slow start and pick up)

1 - 17 of 17 Posts

mr.murf

· #2 · Sep 13, 2012

Have you checked the throttle cable to see if you are getting full throttle?

If you have highway gears in the rear (around 2.73 or 3.08) that will hinder off the line performance.

I checked the 1407 and it's a 750 cfm. That a little large for your engine combo. I would suggest a 600-650 cfm.

Does the car hesitate or bog off the line? ... if so it could be carb related.

Also, have you played around with the timing? Maybe try advancing the initial a bit and seeing how it runs.

Also that idle is pretty low. Is your car a manual or automatic? If auto - Is that idle speed in neutral or in gear?

It could be a number of things.. we need more information.

But i wouldn't expect a whole lot from the combo you have.. it's a pretty mild engine. I have a pretty tame 350 in myself.. it doesn't have all the power in the world but it goes pretty good for what it is.

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chevy2much

· #3 · Sep 13, 2012

Change all fluids and filters.

batman09

· #4 · Sep 13, 2012

Smokedmaxxx said:
Whats up fellas, well this is the story on my nova
Bought from a widow, car sat in garage for 8 yrs
350 (71" 4bolt main, 4bbl) w/ 305 Heads (4416) , Edelbrock 1407, weiand a xcelerator intake manifold, summit 1103 camshaft, stock dual exhaust exiting behind rear wheels, headers, HEI distributor, Rear Gears not sure ( also never removed the oil that I bought it with, someone told me not to mess with that since the old oil has been in their without change so long that it could damage it with new oil??) HELP

Timing @ 8 degrees, total timing @ 32 idle @ 550 running VR-1 10-30 oil

Problem- Accelerator Pedal feels Hard , also I feel like it has no Power (like it has such a slow start and pick up)

I told you in your other post...try more timing....try 2-4 more degrees....also those 305 heads are not helping you at all:no:

1977Chad350

· #5 · Sep 13, 2012

My buddie had bad acceleration and huge power lost on his 305. He just charged the cat out on it car and had a major power increase. To tell if its the cat or cats just unbolt the exhaust in front of them and see if the power comes back. Also does the engine spin over normal or is it slow. It could also be a stretched out timing chain.

sbc1320

· #6 · Sep 13, 2012

1977Chad350 said:
My buddie had bad acceleration and huge power lost on his 305. He just charged the cat out on it car and had a major power increase. To tell if its the cat or cats just unbolt the exhaust in front of them and see if the power comes back. Also does the engine spin over normal or is it slow. It could also be a stretched out timing chain.

Yeap and if it doesn't have a cat, I have seen mufflers rust up and collapse inside causing loss of power. Not hard to diagnose, kind of like opening the water faucet and checking flow. Rev it up and see what kind of tailpipe pressure it has.

Always change fluids in the car if it's been sitting, then after a few hundred miles change them again.

Bump the timing up to 12 degrees. The 305 heads were put on to bring up compression probably.

cdahl383

· #7 · Sep 13, 2012

1.) Check throttle return spring for hard pedal. May be too stiff or may be binding on something.

2.) Advance timing to 10-12 intitial for 34-36 total

3.) Replace stock distributor springs on weights to lighter ones. Many times one light and one medium spring from curve kits works well. Worked well on my stock 307 and on my modified 383.

4.) Verify advance mechanism is not sticking/binding in distributor. Weights should move freely and bring in advance curve smoothly as RPM's rise.

5.) 750 cfm is a little big for stock 350. Try a 600 cfm if available. My old 307 ran awesome with a Edelbrock 600 on it.

I was able to get my 307 to run really good with just a nice 600 carb, curve kit in the distributor (timing all in at 2500 RPM), and a good tune up (new plugs, wires, cap, rotor, etc). It wasnt a drag car or anything, but it had lots of power and felt good on the street. A 350 should have more power than a little 307, so I'm sure with some tuning you can get yours running a little better.

Good luck!

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Smokedmaxxx

Discussion Starter · #8 · Sep 13, 2012

mr.murf said:
Have you checked the throttle cable to see if you are getting full throttle?

If you have highway gears in the rear (around 2.73 or 3.08) that will hinder off the line performance.

I checked the 1407 and it's a 750 cfm. That a little large for your engine combo. I would suggest a 600-650 cfm.

Does the car hesitate or bog off the line? ... if so it could be carb related.

Also, have you played around with the timing? Maybe try advancing the initial a bit and seeing how it runs.

Also that idle is pretty low. Is your car a manual or automatic? If auto - Is that idle speed in neutral or in gear?

It could be a number of things.. we need more information.

But i wouldn't expect a whole lot from the combo you have.. it's a pretty mild engine. I have a pretty tame 350 in myself.. it doesn't have all the power in the world but it goes pretty good for what it is.

Well I didn't reall look at the throttle cable like that, will check
Also don't know what gears but I know my launch should be faster than my uncles ford club wagon 250 and my sisters Toyota Camry 4cyl.. Could be that tho

Yes my carb is a little big I know, it's the one that came with it as soon as I get a buyer Ill get a new one, kinda on a budget you know

With the way it's timed right now , which I will adjust to 10-12, it doesn't hesitate at all..

I set the idle this low because a chevyhead told me the lower the idle the better so if you can keep it around 500-850 would be good, but the lower the better and especially if it doesn't shake and stall... Will bring it up, what would be a good idle with my setup (mild engine)

My car also has the th350 automatic on the floor with b&m shifter, my idle reading are the same idle and in gear

but I know my launch should be faster than my uncles ford club wagon 250 and my sisters Toyota Camry 4cyl.. Could be that tho

Smokedmaxxx

Discussion Starter · #9 · Sep 13, 2012 (Edited)

chevy2much said:
Change all fluids and filters.

Change all fluids when I first got the car , beside the rear gear and transmission, but with the transmission the gears seem to shift pretty good, if it low can I use any transmission fluid or is their a specific kind I need...

Smokedmaxxx

Discussion Starter · #10 · Sep 13, 2012

batman09 said:
I told you in your other post...try more timing....try 2-4 more degrees....also those 305 heads are not helping you at all:no:

Thanks bro will do the timing 2-4 degrees more and test drive each one to see which one rides better and turns on better and smooth, oh yeah I know the 305 are just for more compression old skool trick, which came on the car already

Smokedmaxxx

Discussion Starter · #11 · Sep 13, 2012 (Edited)

sbc1320 said:
Yeap and if it doesn't have a cat, I have seen mufflers rust up and collapse inside causing loss of power. Not hard to diagnose, kind of like opening the water faucet and checking flow. Rev it up and see what kind of tailpipe pressure it has.

Always change fluids in the car if it's been sitting, then after a few hundred miles change them again.

Bump the timing up to 12 degrees. The 305 heads were put on to bring up compression probably.

Honestly that's the first thing that came to mind , I don't have cats, i have the headers then all pipe up until the rear back seats where the mufflers are then pipe until it comes out the behind the rear wheel, also they lookOLD AND could be kinda clogged, cuz I feels like when I accelerate to take off kinda fast , that someone is holding me Back...

Thinking bout cutting where the mufflers begin, and have the pipes come out in front of rear tire

Also timing chain is brand new, from comp cams

sbc1320

· #12 · Sep 13, 2012

Smokedmaxxx said:
Honestly that's the first thing that came to mind , I don't have cats, i have the headers then all pipe up until the rear back seats where the mufflers are then pipe until it comes out the behind the rear wheel, also they lookOLD AND could be kinda clogged, cuz I feels like when I accelerate to take off kinda fast , that someone is holding me Back...

Thinking bout cutting where the mufflers begin, and have the pipes come out in front of rear tire

Also timing chain is brand new, from comp cams

The stock style mufflers (tin type) or turbo mufflers can and will deteriote sometimes. Heavy walled mufflers shouldn't give you any problems. If you hit the gas fast and it doesn't backfire or cough thru the carb, then timing should be ok, but still put it at about 12 degrees.

chevy2much

· #13 · Sep 13, 2012

Smokedmaxxx said:
Change all fluids when I first got the car , beside the rear gear and transmission, but with the transmission the gears seem to shift pretty good, if it low can I use any transmission fluid or is their a specific kind I need...

You need to use dexron or equivalent fluid. Did you change the fuel filter?

mr.murf

· #14 · Sep 13, 2012

Smokedmaxxx said:
Honestly that's the first thing that came to mind , I don't have cats, i have the headers then all pipe up until the rear back seats where the mufflers are then pipe until it comes out the behind the rear wheel, also they lookOLD AND could be kinda clogged, cuz I feels like when I accelerate to take off kinda fast , that someone is holding me Back...

Thinking bout cutting where the mufflers begin, and have the pipes come out in front of rear tire

Also timing chain is brand new, from comp cams

When I ditched the stock manifolds and turbo mufflers for headers, new piping, and magnaflows it felt like it woke up the car a great deal! Plus it sounded a lot better.

You can get an exhaust kit for a pretty reasonable price with new mufflers and do it yourself.

64IIGolfLover

· #15 · Sep 13, 2012 (Edited)

I would do as mentioned above.

Check your throttle return spring and also check the lever on the carb itself where the return spring is located and make sure its returning to the original position. Make sure nothing is binding.

If you say you have a hard pedel your spring might be too stiff, but you just have to push on the gas a little harder from the cockpit.

Secondly, find the initial timing that works best for you. Keep going up in increments as mentioned above. Find the initial that works best, then find the total that works best.

If you bump your initial to 16 I bet your car would like that, but you never know.

Then adjust the timing curve.

Then when you have your timing set, go to your carb and start adjusting your carb.

Does your HEI have a bushing you can put in your distributor to limit the total timing?

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Smokedmaxxx

Discussion Starter · #16 · Sep 14, 2012

chevy2much said:
You need to use dexron or equivalent fluid. Did you change the fuel filter?

Defently changed fuel filter, installed a bigger one also

Smokedmaxxx

Discussion Starter · #17 · Sep 14, 2012

64IIGolfLover said:
I would do as mentioned above.

Check your throttle return spring and also check the lever on the carb itself where the return spring is located and make sure its returning to the original position. Make sure nothing is binding.

If you say you have a hard pedel your spring might be too stiff, but you just have to push on the gas a little harder from the cockpit.

Secondly, find the initial timing that works best for you. Keep going up in increments as mentioned above. Find the initial that works best, then find the total that works best.

If you bump your initial to 16 I bet your car would like that, but you never know.

Then adjust the timing curve.

Then when you have your timing set, go to your carb and start adjusting your carb.

Does your HEI have a bushing you can put in your distributor to limit the total timing?

Yeah I know for a fact now thats the reason for the stiff pedal, because I bought a new spring when I first got the car while doing the whole tune-up thing, even accelerating the car from the carburator is kind of hard ,I'll try to stretch it out a little by hand I guess!
But now the power, will defently try 2moro with the timing at 12-16...I'll keep you guys up to date and a running video

1 - 17 of 17 Posts

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