'72 300 SE L 4.5 - Trouble starting when hot

[Tony Macedo]

The Green Machine, as I call it, runs outrageously well and starts right up every single time...except when I try to re-start it after experiencing stop and go city traffic when the engine gets warmer than usual cruising temps. When it does happen, it seems to fire up only a few cylinders while the starter is cranking...eventually it does start up after a couple backfires...again, it only happens when I re-start the engine after experiencing stop/go traffic...otherwise is never happens. Any idea what to target?

[Tomguy]

Tony: Check out this other thread, maybe it can help with ideas:
72 280SE 4.5 idling issues

Yours sounds more like a maladjusted mixture if it will start hot eventually and, when it does, it does run fine. bullit's sounds more like vaporlock... Check my post where I suggest possibly adjusting the idle mix.

[Brett San Diego]

If this car has a Bosch CIS K-jetronic fuel injection system, hot start problems are most often caused by a bad check valve in fuel pump or possibly a bad fuel accumulator. Both these parts help the system maintain fuel pressure when the car is shut off when hot.

Brett

[kpb]

I think this is a D-Jet car and do not believe there is a fuel accumulator. Dunno about a fuel pump checkvalve. Others here will certainly wiegh in soon with ideas.

[Tomguy]

There is no accumulator. It is a possibility the regulator and/or fuel pump checkvalve are gone, but the initial fuel pump pressure is USUALLY enough to bring the system up.

[body_infinity]

Hi..had a similar problem, need to get a fuel pressure gauge (best place in line with the csv) check for rest pressure if not there then you will need to check for leaks...if no leak (like my situation) then the check valve could be gone or could have metal particles stuck (my situation ) get it cleaned and presto rest pressure is back no more hot start lucky dip

cheers from oz