Finally got to race Wednesday. Times were off by almost a second. No power at WOT. Feels like it is starving for fuel.
Trying not to just go nuts and change this and that and be totally lost as it was running fine without these issues through the end of last season. Only engine type things I have changed since last season are the oil, filter, and inline fuel filter and this past Thursday I changed the fuel pump.
Went racing Saturday and had the same results. My times are ALL consistently off by about a second all the way down the track.
Checked plugs and cleaned. Hit carb with cleaner. Did not change performance.
Not sure what the problem is. I did remove the evap canister early this spring and left the lines open since there is no emissions stuff left on the car. Wonder if that has something to do with this?! I might loop the lines and see if that makes a difference. SOMETHING is causing this car to act like it is starving but it is consistently starving at WOT. This car does not have a garage and was outside under a car cover all winter.
Runs perfectly fine out on the road when it is gradual acceleration or even heavy acceleration. As long as it is not WOT, it's fine.


I have never had the timing checked on the car so I have no idea what it is sitting at.
A little about what I am running in this car:
350 sbc from a late 70's Camaro
600 cfm edelbrock 4bbl carb with mechanical secondaries
stock cam (as far as I known)
headers
accel shorty plugs (due to the limited space with the headers)brand new beginning of last season
Any ideas would be most appreciated!!

 

First guess is fueling, either the fuel pump or filter, if your car is starving for fuel it will definitely show on the top end, followed by evap lines not being blocked off.
I would start with those, definitely get the timing checked for the time it takes, wouldn't hurt

also you may need larger jets in the carb, if the pump is pushing more fuel than the carb can handle this might also be the culprit


It could also be weather related, different temps and humidity make a difference in how the car runs as well as altitude, but I doubt altitude has changed lol

 

Ken-
Yes, my first guess is fuel delivery system. Changed the fuel filter as part of getting it ready for the season. Did this when I changed the oil. Just changed the fuel pump Thursday thinking that could be the problem but no change in performance since Wednesday when I first noticed the problem. I did not think about the evap lines until this afternoon. But like I said, Nothing has been changed in the fuel/spark system since last season (when it was running fine) except the fuel filter,pump, oil, and removal of evap canister.
So I am thinking it has to be one of two things: got a bad new fuel filter, or need to loop evap tubes so they are not sucking air into the fuel system. Guess I better do some research on how this works. I thought they did nothing now since there is no emissions stuff left.


Yes, I need to see what the timing is set at but don't want to change something right at this moment that was not changed between last season and the two days I have run this year.
I checked my records from last year with temp and humidity when determining how much I was off and it is 9 tenths to 1 second off from the exact weather conditions. No, the altitude has not changed!! LOL Thank goodness. Just one less variable to consider.
Once I get this sort of back to normal, I WILL be jetting the carb up because it was running lean all last year.

 

Then it is leaning towards either the filter being bad or the evap. I know when I used to pull them off of my cars I would always put a screw in the hose to stop it from sucking in air, worth a shot to try that first as it is the cheapest route

 

Thanks Ken
Oh now I am almost positive is HAS to be the hoses from the charcoal canister. I jerked the canister out and threw it in the trash about 3 weeks ago because I figured everything else was gone so why did I need it. The hoses that were hooked to it are wide open and not blocked off at all. I can guarantee you it's sucking in air and causing my already lean mixture to be even leaner. ARGHHHH

 

lol, not laughing at you, laughing with you, the chase for horsepower on cars is endless and it's amazing how interrupting one thing in the circuit can make such a difference. The worst is when you fix something and don't know what you did, which sadly I have done in the past lol

 

The search for where my horsepower went is precisely why I did not want to go changing things that had not been messed with over the winter to fix this.
Try one thing at a time so I know what fixed it.
OMG wonder if they would unlock the gates to the track and let me make a test pass tonight???!!! LOL j/k
I cannot believe I left those hoses just wide open...geez
Now the one hose that goes back to the tank needs to be open to vent the tank correct?

 

I believe so, but it's been a while lol, I would probably (this is just me and I am not suggesting anyone try this at home) would try without it plugged and find a back road and run 3 telephone poles (as this is approx a quarter mile) and will give you a test run, but again I am not suggesting you do this as street racing is bad

 

LOL No I do not street race at all...that requires two drivers!! With only one driver it is speeding!!
I do have a spot, on the way to my daughters, where I check how fast the telephone poles are running!!
I did find this little tidbit of information from another source
" Some people who delete their vapor cans often replace them with a fuel filter, this keeps some contaminants out but not moisture. " Which way would the fuel direction arrow be pointed? I would think AWAY from the tank.

 

Ya try it away from the tank first

I wasn't suggesting you do that "street racing" thing or "speeding" lol, I'm just saying when I was younger that is how I would have tested, as I never had access to a track either.