my D won't start.

[steve.s]

Hi all

oh b**ger. since last week she will not start.

put a gallon of fuel in, jumpered the battery, jumped the cold start valve (thats always worked!), cranks over but will not even cough.

not sure but thought i could here a click on turning key to position 2.

cannot hear the pump though, and i thought i normally could.

in the garage i have, cannot open drivers door so cannot reach the inertia switch, but can see 1/4 inch of the rod sticking down. was going to start there, maybe take off the fuel feed to distributor, see if fuel is pumping...then look at electrics.


has new coil, pump etc. and has always at least coughed a bit

has a new rpm relay, but maybe this is suspect.

[Dan6457]

To test the pump is running, unplug the rpm relay and jumper the pins to make the pump run permanantly and see if you can hear the pump running and if it starts then.



If it is the rpm relay, I have a brand new one I bought for my car then found out my original was fine.

[Chris Williams]

Have you done anything in the engine bay since last driving it? knocked the coil lead? I would check all these things first i.e; spark before chasing down the fuel route.
Chris

[Rich H]

Top of the list is the rpm relay as Dan has sugested.

Oddly, mine failed the other day, completely at random

If you can't bodge a jumper together, do what I did and stick a laggy band around the relay inside to hold the contacts closed.

[steve.s]

hi

an update...been on holiday

right, a connected a small test light to the fuel pump connection.

did not light with the rpm relay installed.

then took that off and jumped the corner connections...lit up ok.

now am i right, the rpm has an internal relay that then powers 12v to the pump....hence my rpm relay is duff?.

also, slight spark when jumpering the rpm socket, and wire (pretty heavy guage) was warm.
so i wonder if the pump has failed and seized, shorting out and taking the rpm relay with it?.

tommorrow i will put a fuel can on the end of the fuel feed line and see if the pump is working.

any comments anyone?.

[Glen & Sam]

hi steve

if you need a hand im in your area all afternoon give me a call

[steve.s]

Hi glen

thankyou for that.

i will probably struggle to do anything today, as i am on site (building).

do you work in Wolverhampton?.

Regards

steve

[Dan6457]

If you need a new RPM relay I have a brand new one I bought but didn't need.

[NickT]

steve.s Wrote:hi

an update...been on holiday

right, a connected a small test light to the fuel pump connection.

did not light with the rpm relay installed.

then took that off and jumped the corner connections...lit up ok.

now am i right, the rpm has an internal relay that then powers 12v to the pump....hence my rpm relay is duff?.

also, slight spark when jumpering the rpm socket, and wire (pretty heavy guage) was warm.
so i wonder if the pump has failed and seized, shorting out and taking the rpm relay with it?.

tommorrow i will put a fuel can on the end of the fuel feed line and see if the pump is working.

any comments anyone?.

Hi Steve,

Although you have probably tested for a positive feed to the fuel pump with your RPM relay tests, you probably haven't tested the earth return from the pump. Wired in series with this earth return is the inertia fuel cut off switch, located above the clutch pedal(ish). This has a plunger on top and these do fail open circuit. You could try moving the "plunger" to the opposite position and try again.

For further testing it would be best if you removed the spare wheel and the plastic cover to the fuel tank/ pump.

Disconnect the electrical connector to the fuel pump.

"Jumper" the fuel pump as Dan posted.

Use a multimeter set to Volts (20v range) and test for voltage across the pins of the plug.

If you get battery voltage then it would indicate a pump issue.

If you don't get battery voltage, put the black wire of your multimeter to one of the wings or ideally battery negative post and test the WHITE/PURPLE wire in the electrical plug for battery voltage.

If you now get battery voltage then you are getting a supply to the pump but no earth return. To test, reconnect electrical connector then TEMPORARILY use a 10Amp FUSED cable piggy backed in the BLACK/ PURPLE wire and an earth point on the car.

If the pump now works then it will be the inertia switch and/ or the assicated wiring.

Look at:

http://www.deloreans.co.uk/technical/ma ... ystems.pdf

PDF page 18, manual page 144.

You could also try connecting 12v directly to the fuel pump (using FUSED cable) to see if it works/ runs, but only do this in a ventilated atmosphere and you have no fuel leaks etc. Wouldn't want you to go BOOM !

Hope this helps,

NickT

[Glen & Sam]

hi steve

most days anyway one day i can be in wolverhampton next day in ireland building bttf cars :lol:

let me know if you need a hand but really nic t is the man for help :wink:

[steve.s]

hi Glen and all

i managed to squeeze 1/2 hour tonight.

took the cover off the rpm relay, and pushed the relay contacts.

a test light on the fuel pump connector under the hood lit ok.

high pitched buzz from the frequency valve, not noticed this before.

so connected the fuel pump, took the fuel line off the fuel distributor and closed the rpm relay.

nothing...no fuel, but frequency valve buzzed

so from this i think my rpm relay has died, along with the pump....both are only a few months old.

maybe worth soldering a new 555 timer chip?, and i will order a pump.

anyone have the bosche number to hand, complete with valve?

[Glen & Sam]

STEVE

i have some time tomorrow if you get some time give us a ring and we have a play if you want alan is not far from you so we could take the parts of his car and test them on yours if needed savesbuying new kit if its not needed

[NickT]

steve.s Wrote:hi Glen and all

i managed to squeeze 1/2 hour tonight.

took the cover off the rpm relay, and pushed the relay contacts.

a test light on the fuel pump connector under the hood lit ok.

high pitched buzz from the frequency valve, not noticed this before.

so connected the fuel pump, took the fuel line off the fuel distributor and closed the rpm relay.

nothing...no fuel, but frequency valve buzzed

so from this i think my rpm relay has died, along with the pump....both are only a few months old.

maybe worth soldering a new 555 timer chip?, and i will order a pump.

anyone have the bosche number to hand, complete with valve?

Do the tests on my previous post instead of part swapping and then we can take it from there.

NickT

[steve.s]

hi

thought i would update.

just fitted a new pump....and started fine with a jump kit as the battery is now dead!.

i'm not convinced the rpm relay is ok, so have a new chip to solder in.

hopefull take here out on Saturday, and hopefully she will be ok