ok girls and boys,

patient is w126 chassis 1987 420sel

she tries to die (successfully i might add) when i step on the gas pedal...also has very tough time starting....cranks over fine but since she sits a bit....

so im thinking obvious things like fuel filter and fuel pump relay to start....

pls advise any other ideas...

lyle in west texas

Lyle, first step would be to replace the fuel filter which should be done every 60,000 miles.

__________________
Fred Hoelzle

I have the same problem with my 420SEL ! Except now it will not start at all. Good strong spark,compression good and even.It will not try to start w/ starting fluid !!!

lyle_H:

1. Check the over voltage protection (OVP) relay, there is a fuse on top of it and it is located on the firewall a bit left of center.

2. Ensure that BOTH fuel pumps are running.

3. Ensure that the cold start valve is spraying fuel during a start attempt.


James Peters:

Check OVP, your description sounds like no power to the fuel pumps.

what i did was have my local guy wire my fuel pump to the battery and put a switch in, so i manually turn on the fuel pump, so i have power to the fuel pump....

could i still have an OVP issue?

lyle in west texas

I has good fuel pressure and will not try to start even with starting fluid. You can hear the pump spool-up at key on.

to james peters:

right now car is idling rough....how does one know if the second fuel pump is running without getting under the chassis? i am but one person

lyle in texas

You really need to understand the system, and how to diagnose issues.
These should help.

http://www.peachparts.com/shopforum/diy-links-parts-category/142406-fuel-injection.html

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