Hot start issues - do these details sound like my accumulator is bad?

Update #2:
Last night I ran the car as it was cooling down to repeat the sane conditions as the day before. Fuel in the lines, and then I shut it down right away before it got hot.

This afternoon I started it and it fired right up.
I shut it off, disconnected the rear line on the accumulator, plugged the hose, and put another hose from the accumulator to a catch container. Started the engine. And fuel steadily streamed out of the hose until I shut it off. This was not residual- I let it flow for about 10 seconds and it did not slow down. It was not a gush of fuel, but more than drips. It was a steady, small stream. (Picture attached)

I reconnected the fuel accumulator, ran the engine up to temperature, and shut it down. Waited a few hours to allow it to (apparently) vapor lock again.

I do not have a dwell meter to check the mixture.

After a few hours, I tried to start it. No start.
I disconnected the CSV. No start.
I plugged the WUR canon plug into the CSV. It stumbled for an *instant* and died. It did not fully start.
I reconnected the plugs as they should be; no start.
I pushed down and released the air plate firmly and swiftly released. It started after that.

So, accumulator, right?

It certainly looks like it. Before replacing the accumulator, I suggest looking at my missteps when I did it (http://dmctalk.org/showthread.php?16...om-accumulator) so that you don't repeat them. One benefit of replacing the accumulator is that you also replace the soft fuel lines that connect to it. Underneath the cloth wrapping, mine were extremely brittle, and looked ready to split - I think due in part to the alcohol in our fuel.

Yes, certainly a bad accumulator.

The rear accumulator fitting you attached the test hose to acts as a vent (to vent the air in the back of the accumulator when the spring-loaded bellows moves backward as it accumulates pressurized fuel) AND it acts as a safety overflow return port to the fuel tank wehn the accumulator bellows leaks/fails.

The good news is failed accumulators don't visibly leak fuel - no mess and no fire danger. If properly installed, that is.
The bad news is failed accumulators aren't obviously bad because they don't visibly leak fuel when plumbed normally.

Thanks for the thorough reporting - and that photo of the accumulator test hose in action.

Quote:

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Originally Posted by jackb

Update #2:
Last night I ran the car as it was cooling down to repeat the sane conditions as the day before. Fuel in the lines, and then I shut it down right away before it got hot.

This afternoon I started it and it fired right up.

I shut it off, disconnected the rear line on the accumulator, plugged the hose, and put another hose from the accumulator to a catch container. Started the engine. And fuel steadily streamed out of the hose until I shut it off. This was not residual- I let it flow for about 10 seconds and it did not slow down. It was not a gush of fuel, but more than drips. It was a steady, small stream. (Picture attached)

So, accumulator, right?

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I ordered a Bosch accumulator part number 0438170029 on ebay; it should be here next week.

Your starting system will thank you.

Just an update to close out this thread, in case someone comes across it in a future search: The accumulator was 100% the cause of my hot-start (and cold start, really) issues. It starts perfectly every time now, no matter what.

I cut up my old accumulator to see what it looks like inside. There is a giant heavy duty strong spring in the skinnier part, and a metal disc w/ a diaphragm in the center. I guess when I cut it the body of the accumulator got mishapen enough from being held in a vise, and I was not able to get it out. I beat the hell out of the disc with a hammer, and tried pressing it out with a shop press, crushing it to shit in the process. It was intact originally, but you can see in the pictures the guts of the accumulator, if anyone is curious.

Excellent news and thanks for sharing the teardown photos.

I've seen the schematics of the x-section of the Bosch accumulator but never have seen the guts.

Quote:

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Originally Posted by jackb

Just an update to close out this thread, in case someone comes across it in a future search: The accumulator was 100% the cause of my hot-start (and cold start, really) issues. It starts perfectly every time now, no matter what.

I cut up my old accumulator to see what it looks like inside. There is a giant heavy duty strong spring in the skinnier part, and a metal disc w/ a diaphragm in the center. I guess when I cut it the body of the accumulator got mishapen enough from being held in a vise, and I was not able to get it out. I beat the hell out of the disc with a hammer, and tried pressing it out with a shop press, crushing it to shit in the process. It was intact originally, but you can see in the pictures the guts of the accumulator, if anyone is curious.

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Your photos show different parts inside. So mine must have been a newer built.