Re: Fuel System Contamination (Long)

["content22207" <brobertson@xxxx>]

Fuel tank pickup is a DeLorean achilles heel. If you own a D, the fuel
tank/pump/boot/etc are going to need more attention than other brands.
Is a simple fact.

Note that this is not a terminal issue. Nor is it worth TOTALLY
re-engineering (are better components however -- as long as you're
replacing, why not use upgrades). Just don't take it for granted.

Things to watch out for:
- Old & weak fuel pump. They do wear out. Remember: this unit is what
ultimately vaporizes fuel from the injectors (yes, via a small
diameter pipe to the filter) -- isn't it worth a hundred dollars or so
to be sure you've got optimal fuel burn? Later pumps also have
improved check valve.
- Deteriorated fuel pump boot. This guy holds the pump in the fuel.
Also seals the tank from water or other contaminants that may find
their way under pump cover (a notoriously ill fitting device, see
below). Is an extremely harsh environment even for new rubber. Not
only will an old boot fail to hold and seal the pump, but pieces of it
will crumble into tank (ultimate contamination).
- Fuel pump cover. Starts out as a tight fitting cap for pump & boot.
Has tight fitting passages for fuel lines. Electrical connections must
be carefully threaded through notches between cap and boot. THEN it
becomes hard and shrinks. Personally, it irritates me so I left off.
*BUT* my pump is totally isolated from windshield plenum drain hole by
a custom aluminum shield -- unless your plenum drain hose is intact or
another solution rigged up like mine, better not omit (boot will fill
with water and rust electrical connections on the pump).
- Fuel tank baffle. Because tank is flat bottomed, you need a baffle
when going around corners. Stock baffle is composed of three pieces,
connected to the pump by a custom formed rubber hose (remember what I
said Re: rubber in the tank?). IMHO is unnecessarily complicated -- am
totally sold on John Hervey's replacement (he's not even paying me to
say that). Mine was a total loss anyway: plastic hopelessly gummed,
pickup screens so brittle they crumbled between fingers, connecting
hose collapsing and gooey. For the price of replacement hose alone got
an aluminum baffle and screen that is simply engineered directly under
the pump.
- Fluorelastometric hoses connecting pump to metal fuel lines towards
rear of car. This is tough stuff. Unless it's been kinked or bent,
probably does not leak. But you may find lining of original hoses too
stiff to fit on new pump. Outer sheath may be deteriorated. You've
come this far, buy 3 feet or so of new hose...

Head spinning yet? Hang in there -- that was only three or four
components. Anyone with rudimentary mechanical skills can install.
$200 - $300 dollars: small price for years of trouble free maximum
performance.

Accumulator is basically a can of gas with a spring loaded diaphragm.
Pressurizes the fuel system before engine running, and evens out
pulses from RPM relay to the pump thereafter. Extremely little chance
the housing itself will ever leak. Extremely high chance the diaphragm
inside will go bad, rendering the thing useless. Are ways around a
dead accumulator, but are better ways to impress a woman than
re-wiring the car on a date. If you really can't spare $140 to
replace, post another message for the bypass procedures.

Cross referenced fuel filter is $15. Replace it.

Fuel distributor is rumored non-serviceable by average mechanic.
Apparently factory seal impossible to replicate. Since you've come all
the way to back of car, why not run it for a bit then examine spray
pattern from injectors in a glass container. If any are clogged, they
CAN be cleaned (with fuel injector cleaning machines). John Hervey's
price on a replacement set of 6 might even be cheaper. In any case, as
long as fuel metering piston operating correctly, contamination issues
from distributor to injectors are correctable.

Better stop here before Moderator tapes my mouth shut. Fuel system is
crucial. Components do not age well. Replacements are available and
fairly affordable. Properly maintained system will be a non issue in
your future.

Good luck.

Bill Robertson
#5939 (out of sling, on the road again -- watch out...)

>--- In dmcnews@xxxxxxxxxxxxxxx, "deloreanz" <deloreanz@xxxx> wrote:
> Thanks for all the help in the past. Is there any proceedure i can 
> follow to check how far the fuel contamination has gotten(like if it 
> got past the accumulator/distributor up to the injectors? I'm 
> considering just replacing the fuel pump/accumulator/filter just to 
> be safe, is that absolutely nessesary or could I check if any of 
> those are still good? Also how could i check the distributor for rust
> (hence injector contamination)? Thanks again,