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another starting problem
#1
Hi all
Got a problem like many with hot start. Seems that if it fails to start the first turn of the key when hot theres no way it will go until cold.

Fuel filter has been replaced, checked for leaks, pump in tank runs (runs a bit more when you flash headlights) pick up pipe looks ok ,accumulator was replaced in 2000,replaced rubber seals in fuel distributor, pressure seems to hold in system as air flow sensor plate is quite firm to press down when hot (easy to press in the morning but starts fine then) Plugs look fine just the colour they should be ,when it fails to start they are sparking and are dry (not flooded)

When running the car is fine a little bit of an uneven idle when hot but nothing to worry about.
Emissions where good cant remember what but well within the limits.

Any one have any ideas
cheers Brian

! At least the radio works!
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#2
Unfortunately the classic hot start failure is usually attributed to the accumulator. You say yours was replaced in 2000. I'm not sure what the life expectancy of one of those components is, but from my own experience I'm afraid that's where I'd start. If I remember correctly it set me back about £80, but cured the problem 100%.

And to add to the fun, they're a real pain to do as well. You can either see it, or have your hand in the recess, but not both at the same time...

Anyone else have any suggestions?
Richard Hanlon
Derbyshire
DOC 393

1981 DMC-12 VIN 06126
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#3
Just cant understand why the air flow sensor plate is hard to push down.

Where is the best place to get the accumulator from?
I can see it doesnt look easy to get at.
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#4
If not the accumulator then try this:
[ATTACHMENT NOT FOUND]

As per John's website approx 3/4 way down the page:
http://www.specialtauto.com/delorean-pa ... ction.html

Chris
Membership Secretary DOC UK
2021's DeLorean event: http://www.deloreans.co.uk/forum/showthr...p?tid=6056
VIN#15768 Ex VIN#4584
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#5
Brian morgan Wrote:Just cant understand why the air flow sensor plate is hard to push down.

Because the pump isn't running and the return path is therefore closed in the pressure regulator. This is a red herring - you need to get a gauge on there and watch what the pressure does, although can probably tell you from what you describe.

There are 3 potential hot start problems:

Accumulator
Primary pressure regulator O-rings shown above
Fuel pump check valve.
Martin Gutkowski
DeLorean Cars
http://www.delorean.co.uk
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#6
Looks like i might have to go for the accumulator.
Will try and get a pressure test first .Do I tee into a line from the fuel distributer to an injector,am i able to tell if its a pump check valve or accumulator by conecting and taking a reading in a different place, what should the pressure be.
If i need a accumulator where is the best place to get one from.

many thanks
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#7
A pressure gauge can be hooked up anywhere if you're checking for hot start issues. My favourite spot is where the cold start injector comes off. It should hold rest pressure for a good half hour to an hour after switching off the engine.

For checking the behaciour of the control pressure regulator, you need to hook it up in the control pressure line... but that's academic for your problems.

I would start by replacing the O-rings and fuel pump check valve - a you've already done the accumulator and it's by far the most expensive bit, it would make sense to rule the other two out first.
Martin Gutkowski
DeLorean Cars
http://www.delorean.co.uk
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#8
Ive done the o rings made no difference. Is the check valve an integral part of the pump?
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#9
Do yourself a favour and check out the O-rings again. The general advice for those is "if it ain't broke, don't fix it" -there have been numerous cases of people having replaced these O-rings and the little one at the end failing again - it looks as if someone has taken a little chunk out of it.

The check valve is a rare failure, and it depends on the car as to whether it has the integral valve or a seperate one. If the hose attaches to the pump by a banjo bolt, then it's integral, if it's a dome nut, then it's seperate and can be replaced. Costs about £7
Martin Gutkowski
DeLorean Cars
http://www.delorean.co.uk
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