250SL Hot start

I have a 67 250SL, when starting after a hot soak 10-15 min. it is very hard to start, starter is working fine, ign is good, if you wait another 10 to 15 min. it will start right up. Cold start is fine, CO% hot is 3%.
We use Chevron High test. Could this be a morden fuel problem?

[Alain V.]

You may be experiencing a "vapor lock" problem, especially if the fuel has a high alcohol content. This sound weird, but next time you drive it, open the hood immediatly after shutting the car off. After it sits for a few minutes, try to start it and see if it is any easier. I have seen this with early EFI v-8s in this area alot when folks travel and get a tankfull of "gasohol".


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[Arthur Dalton]

Common problem on the 230/250sl series. The factory solved this with the addition of a time switch to momentarily energize the start valve for a second when hot starting. That relieved any hot vapor problem. The 280sl had this newer design.
The easy and preferred method is to install a momentary switch under the dash that activates the start valve at the drivers discreation. Kind of an electric choke. The advantages are you control the starting procedure. It is also nice for the DIYer as you can turn the engine over when working on it [ as in valve adjusting] without gas being pumped into the engine when cranking.
For thoes that prefer to go the stock route, there is a relay and harness kit to modify the system. Email me directly for that info.
Arthur
113 Tech.