Hi, I have a 67 442 with a 69-455. Just had the engine rebuilt. Bored .040, comp cam, rollers, offenhause manifold, etc. Has lots of power. The problem I am having is hard starting when it's hot. I've tried not even touching the gas and it makes not difference. I eventually have to floor the gas to clear the flooding and it starts. Naturally, it rocks and rumbles for a few seconds or so....then it's fine. I looked out on the internet this morning. Saw an artical that discussed a ROB Mc fuel pump with a return line cthat may be a fix to this problem. Has anyone had this problem. If so how did you correct it? What is a ROB Mc pump and where do I get one?

I have a new flame thrower coil, timing is not retarded, using a rubber line from the fuel pump to the carb (Carter AFB). Thanks for your help.

 

I had the same problem with my '72 and started a thread on here a while back.

I ended up changing out the fuel pump and line (stainless), fuel filter and housing,coil, new points and plugs and a tune up, condenser, regulator and battery. Not necessarily in that order.

The last 3 items changed were the coil, regulator and battery.

She hasn't acted up since.

You can read the whole thread by searching on my sreen name.

Good luck!

 

I had a chevy 350 (argh--in my 67 cutlass) that had that symptom. Would run decent for a while, but on warmer days it would fail to restart after running it to get warmed up for a while. In fact, it wouldn't even turn over until it cooled down.

Hopefully this is not your exact symptom as my problem turned out to be less than 1 psi of oil pressure and deeply gouged main and rod bearings. Go figure (sarcasm).

Best of luck

 

Check to see if you have the heat shield on the starter. The 455 is supposed to have it and many times they were chunked my the first cheap mechanic to change the starter. It also acts as an important brace from the side of the starter to the block.

Heat soak to the starter can make it turn over slower, giving hot start problems. First instinct would be to pump the gas pedal, causing flooding.

 

Thanks again for your thoughts. I have a new high torque starter, new coil, new regulator, and new everything else. The rebuild has less then 100 miles on it. Turns over strong, but I have to floor the gas to clear the flooding, It does start each time after several seconds of turning and flooring. Stumbles then runs strong until I turn it off again and try to restart. Maybe I should have the carb rebuilt....thoughts????

 

Thanks for the clarifications. Sounds like the starter is just fine.

I assume you are using the stock-type mechanical fuel pump...
Have you checked the choke position after the car has sat a while hot? If for some reason the choke is part closed it may flood some when cranked hot. If the carb has not been rebuilt for a long time, then doing so surely couldn't hurt. A sinking float or an internal leak could cause an overly rich starting condition...

 

There was a similar thread here a while back where it was never told that a high pressure electric fuel pump was being used with no regulator and after 3 or 4 carb swaps the problem was still there.....so if you do have an electric pump make sure the pressure is not too high. However in that instance i believe the carb was flooding when running and not when shut down. I would suspect a float level problem or leak in the fuel bowl.

 

Too much fuel.

http://www.robbmcperformance.com/

Potential fire hazard..

The factory used steel line, for good reason.

What he said.

Norm

 

Hi, thank you all for your help. It seems to be gradually getting better. I have found that if I don't even go near the gas pedal it starts ok "hot" after turning over 4-5 times. Again, thanks this site is great!!!!! You folks are Great too!!!

 

Almost sounds like a mild case of vapor lock. can the fuel line be rerouted? May be ad a carb spacer. Just a guess.

 

Now that I'm thinking about it a little more I had a small block s10 that had that problem. we end up having the floats hanging up just a little, but the thing always ran a little sweet, and would load up at idle. don't know if any of this helps or not.

 

Hi Guys, it is back...hard starting when hot. I am suspection a vapor lock. Reason being; I happened to touch the inlet side, on the carb, fuel line and it was too hot to touch. Also, hot out again. I will try installing a steel fuel line and see if this makes a difference. Also, am using a Carter AFB (says racing carb on the carb sticker). Would this effect anything. The mechanic that rebuilt the engine suggest we retard the timing a bit. Thoughts???

 

Just so we have all the info, when the engine is hot, does the starter spin it over at the normal speed, or is it slow. Does the speed vary during cranking? If the latter, then it may be over advanced timing, but I wouldn't hold my breath on that. If it spins at the correct speed, then it does sound like either percolation or improperly adjusted float. If it's percolation, a nonmetallic carb spacer may help.

 

Hi Joe, the stater is a high torq starter. Spins normally with no drag down as it spins. The carb looks great, but it came with the car and I don't know the history. Maybe I need to have it rebuilt. I have very little space between the top of the air cleaner and hood insulation. I have had to go to a 2 1/4 in K & N filter (down from 3") in order to clear the hood. I have an Offenhauser intake man. I have ordered the K & N filer top to give it more air. This might help some, but won't bet on it. Thanks

 

Found the problem. A gasket was cracked in the carb throat dumping gas directly inot the carb, thus flooding it. Rather then rebuild the Carter carb I opted to replace it with an Edlebrock 750. I also installed a carb spacer...bottomline...it's fixed and starts well when hot. Thanks for your help and comments.

 

Glad you were able to fix it, but isn't the Edelbrock just a Carter AFB with an Edelbrock sticker on it? Or is this one of the Edelbrock Qjets?

 

Q-Jet clones were, and AFB clones are, manufactured by Weber, for Edelbrock.

All parts interchange with those made by Carter and Rochester.

Norm

 

hard starting with a big block is a simple solution.
change the positive battery cables and the ground cables to
tractor size battery cables 0 gauge and never have cranking issues again.
get the battery voltage to the dang starter!