Date registered: Jan 2006
Vehicle: 73 280SE 4.5, 71 300SEL, 03 BMW Z4, 72 Fiat 850, 80 Triumph TR7, 85 Porsche 911
Location: DC Area
Mentioned: 1 Post(s)
Quoted: 104 Post(s)
4.5 fuel "flooding" issues
After returning from a lengthy deployment, I took my 280SE 4.5 out of storage (dad) and intended to use it as my transport to a new job. It ran so poorly that I ended up having the thing delivered to me. After working out all the bugs, one remains:
After a good run of 20 mins or so, I'll park the car for the same period of time, and when trying to start it again, the thing barely starts (a "no start while hot" condition"). If the car had carbs, I'd say it was flooded. This was abnormal from when I left it with dad.
Research suggests the injector seals were bad, but I replaced those about 5000 miles ago and they generally don't get rusty. More research suggested that the check valve in the fuel pump was bad, allowing gas to flow back to the tank, further allowing vapor in the lines to form.
Some background to this was that dad let it sit for so long that the fuel pump rusted, as did the tank. I boiled out the tank and the fuel pump was taken off the car, ran backward with some WD40 in it, and all the rust was blown out. I disconnected the cold start valve, but without effect.
Question: will a shot check valve in the fuel pump cause my symptoms? And if so, where is this thing located? Internal to the pump?