Hot engine, hard start after sitting.
#1
Hot engine, hard start after sitting.
Hot engine, hard start after sitting.
1971 olds 455 v8, edelbrock Performer Intake, C heads, Holley 4160 double pumper mechanical, 750 cfm.
Now the weather is warming up it seems like a hot start after sitting for some time, like 30 minutes, it acts like its flooded and I have to hold the pedal and crank, then rev it for about 20 seconds and it clears up. Gets black smoke then its fine after clearing up.
I've checked for fuel bubbling out or fuel leaking after shutdown, can't find anything.
Is it possible the fuel vaporizes and floods my filter top with vapors from the heat?
I adjusted my 4 corner idle and stuff for the warmer weather and turned my choke off completely, I have yet to test it again.
I wanted to ask if there was something more I could do to help this, however it isn't an issue for me at this time.
1971 olds 455 v8, edelbrock Performer Intake, C heads, Holley 4160 double pumper mechanical, 750 cfm.
Now the weather is warming up it seems like a hot start after sitting for some time, like 30 minutes, it acts like its flooded and I have to hold the pedal and crank, then rev it for about 20 seconds and it clears up. Gets black smoke then its fine after clearing up.
I've checked for fuel bubbling out or fuel leaking after shutdown, can't find anything.
Is it possible the fuel vaporizes and floods my filter top with vapors from the heat?
I adjusted my 4 corner idle and stuff for the warmer weather and turned my choke off completely, I have yet to test it again.
I wanted to ask if there was something more I could do to help this, however it isn't an issue for me at this time.
Last edited by GHOSTOWLGRID; April 2nd, 2017 at 12:55 PM. Reason: added
#3
Float levels are at the bottom edge according to Holley that is where it should be.
Whatever the stock 71 olds 455 pump provides, that is what I have for fuel pressure.
I also did just install a new gas tank because my old one had a leak in the top, the new tank holds pressure and has a new venting cap which seems to be working correctly, now and then I hear it vent.
Could it be possible the tank pressure is pushing fuel into the carb through the pump slowly while the car sits?
The tank sending unit has a vapor tube with emissions canister and stuff for the olds 307 that used to be in the car. That tube is plugged now and the canister is removed.
Forgot to say, hot day cold start is fine, turn of warm/hot and restart warm/hot a few minutes later and its fine on a hot day, sits about 30 minutes or an hour hot and it has this issue where it is overly rich on startup. sits longer and the issue goes away.
Last edited by GHOSTOWLGRID; April 2nd, 2017 at 01:27 PM. Reason: added
#4
Mine does the same thing. I don't know the root cause (figured it was scorching underhood temps during 120+ degree summer days) and I just learned to live with it.
Last edited by Fun71; April 2nd, 2017 at 09:16 PM.
#5
Maybe its normal. lol
Last edited by GHOSTOWLGRID; April 2nd, 2017 at 01:49 PM. Reason: added
#6
My guess is that the fuel percolates in the float bowl after the engine is shut down and that causes flooding, which necessitates holding the throttle wide open during cranking to get the engine to start.
#9
That's a good idea for alleviating the symptom under discussion, but I actually had to increase the float level since the fuel pump couldn't keep up with the demand at higher RPM and the float bowl would run low causing the engine to fall flat on its face. Many years go I had a Holley high output mechanical fuel pump, but it suffered the classic crack across the pump arm so I reverted to a factory replacement Carter pump and it can't always keep up with demand.
#10
Last week after driving in my gears for an hour i came back home, and even investigated the case. Took filter-base off, and the fuel was literally boiling on carb, spreading the fumes across the yard. It dont start right away when you turn it off, wait a minute or two and it starts.
I can get it started, but my fiancee wont. Ive also adjusted to live with it. I quess the temp is just too high, when the whole block is heated up and theres no fresh air washing the engine-bays heat off when parked.
Last edited by Inline; April 2nd, 2017 at 09:45 PM.
#11
I put a 1" 4 hole Plastic (phlenolic or some kind of plastic like that, Geez that sounds like a drink haha, I better get to bed!!) carb spacer under my edelbrock 600 and it helped out alot. You may want to give it a try.
Eric
Eric
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