69 Gas Perculation..............

[Kevin D.]

hello new member I have a 69 with a 350cu,350 H.P. and when I'm riding around on a 90 degree day in stop and go traffic the idle is rough and it wants to stall. I keep my foot on the gas and rev it to keep it from stalling. It has stalled a couple of times and it will not start back up. I have to wait about 15 to 20 minutes before it will start. The temperature is above 210 degree mark but below 230 mark. Any ideas........

[Joe L.]

Re: 69 Gas Perculation..............

hello new member I have a 69 with a 350cu,350 H.P. and when I'm riding around on a 90 degree day in stop and go traffic the idle is rough and it wants to stall. I keep my foot on the gas and rev it to keep it from stalling. It has stalled a couple of times and it will not start back up. I have to wait about 15 to 20 minutes before it will start. The temperature is above 210 degree mark but below 230 mark. Any ideas........

Kevin-----

Although it's usually not connected with a hot ambient temperatures, your stalling problem sounds a lot like problems caused by a "heavy" carburetor float. This is caused by age and the deterioration of the gasoline-resistant coating on the plastic nitrophyl float. Rebuilding the carb and replacing the float is the solution if this is the underlying problem.

By no hot restart, do you mean a condition under which the engine will not crank for 15-20 minutes or a condition in which it will crank but not start?

[Kevin D.]

Re: 69 Gas Perculation..............

The engine will crank and almost start then die. It works fine on a cool day say about 70 degree,no problems...................

[Joe L.]

Re: 69 Gas Perculation..............

The engine will crank and almost start then die. It works fine on a cool day say about 70 degree,no problems...................

Kevin----


Do you have a completely stock and as-original fuel system, including the GF-432 fuel filter with fuel return line? Are you using a vented gas cap, as original?

[Kevin D.]

Re: 69 Gas Perculation..............

I have changed to using a in-line filter without the fuel return and using the fuel return line to a 70 fuel pump..........

[Joe L.]

Re: 69 Gas Perculation..............

I have changed to using a in-line filter without the fuel return and using the fuel return line to a 70 fuel pump..........

Kevin----

On the surface, I wouldn't think that change would cause a problem. However, at the same time, I think that your problems are somehow rooted in that change. It may be that the 70+ Q-Jets were in some way changed to be compatible with the revised fuel return set-up. Since you're probably using a 1969 Q-Jet, yours might not be compatible. It may also be that as part of your change, the fuel line or the fuel filter are running too close to areas that get hot.

I would recommend returning the car to the original fuel line and filter configuration. The current replacement GF-432's are a little larger in OD and will not fit into original brackets. However, you don't absolutely need to use the brackets---L-36 applications with the GF-432 didn't use a bracket. So, all you need to do is to obtain a reproduction fuel line set (pump-to-carb), GF-432 filter, and AC 40482 pump.

[Kevin D.]

Re: 69 Gas Perculation..............

Thanks Joe for your help hopefully I'll be driving the shark on a hot sunny day with the t-tops off and the back window removed feeling the wind and sun....................

[John D.]

Re: 69 Gas Perculation..............

hello new member I have a 69 with a 350cu,350 H.P. and when I'm riding around on a 90 degree day in stop and go traffic the idle is rough and it wants to stall. I keep my foot on the gas and rev it to keep it from stalling. It has stalled a couple of times and it will not start back up. I have to wait about 15 to 20 minutes before it will start. The temperature is above 210 degree mark but below 230 mark. Any ideas........

Try some higher grade fuel also. If you want to conduct an experiment get rid or use up your crap pump gas and give the car a real treat. Dump in about 10 gallons of 100LL from a local small airport and see if the situation improves.

[Terry B.]

Re: 69 Gas Perculation..............

[quote=Joe Lucia (12484);353636]Kevin----

The current replacement GF-432's are a little larger in OD and will not fit into original brackets. However, you don't absolutely need to use the brackets---L-36 applications with the GF-432 didn't use a bracket. So, all you need to do is to obtain a reproduction fuel line set (pump-to-carb), GF-432 filter, and AC 40482 pump.[/quoteJoe,

I have for years suspected that the bracket was not used for the L-36 '68 Corvette. It just didn't fit. Is this true here too? The judging manual has it wrong if the bracket to hold the filter is not used. How can this be documented or is it and I just didn't know? I've been dinged points on this many times. Thanks!

[Jim T.]

Re: 69 Gas Perculation..............

100LL at our airport, full service is over $6.00 a gallon. No self serve available, however airports close by that have self serve pumps sell 100LL for couple dollars less.

[John D.]

Re: 69 Gas Perculation..............

100LL at our airport, full service is over $6.00 a gallon. No self serve available, however airports close by that have self serve pumps sell 100LL for couple dollars less.

Jim, Two weeks ago I paid 54.50 + or - for 10 gallonsof 100LL for my 63. No self service for sure. Typical price today is what you said. 6 buks. Course rot gut at the local station is 4.45 for 93.
My 04 GMC 2500 has been getting really sick on 87. So last week when I was hauling the 63 FI car (LWC) around in a trailer I put 100 buks of 93 in the GMC 6.0 and man oh man it was like it had another 100 HP. What a difference. Course you can't tell anyone that. I bet it got better gas mileage also. But it does hurt your wallet. John D.

[Joe L.]

Re: 69 Gas Perculation..............

[quote=Terry Buchanan (32872);353708]

Kevin----

The current replacement GF-432's are a little larger in OD and will not fit into original brackets. However, you don't absolutely need to use the brackets---L-36 applications with the GF-432 didn't use a bracket. So, all you need to do is to obtain a reproduction fuel line set (pump-to-carb), GF-432 filter, and AC 40482 pump.[/quoteJoe,

I have for years suspected that the bracket was not used for the L-36 '68 Corvette. It just didn't fit. Is this true here too? The judging manual has it wrong if the bracket to hold the filter is not used. How can this be documented or is it and I just didn't know? I've been dinged points on this many times. Thanks!

Terry-----


1969 showed no bracket for the fuel filter for L-36 applications; 1968 does show a bracket. I don't see how one could have actually been installed, though. The only bracket I know of was designed to fit the small block AIR pump bracket; it wouldn't fit on the big block pump bracket.

I guess it would take observation of KNOWN ORIGINAL 1968 L-36 Corvettes to determine this one way or the other. I've certainly never made a study of it, though.

Plus, if the bracket had worked for 1968, why would they have dropped it for 1969? The installations were exactly the same in configuration between the two years.

[Clem Z.]

Re: 69 Gas Perculation..............

I have changed to using a in-line filter without the fuel return and using the fuel return line to a 70 fuel pump..........

if you did away with the return line fuel filter and have the same fuel pump you could have excess fuel pressure because that return line is a calibrated leak and the fuel pump pressure is increased to compensate for the "leak".