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302 EFI Engine refrains from starting

Started by MkIV Lux, July 03, 2018, 15:31:16

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MkIV Lux

Urgent help needed :-\
My 1993 Mk IV with standard 302 EFI engine does not start.
Fuel pump OK - fuel available at the injection ramp
Ignition OK
Engine is cranked OK
Injectors however are DRY: injectors obviously are not commanded/steared properly or at all.

How to source the problem?
Thanks for any help
Constant

Flyinghorse

Constant,
The Injectors need to be commanded as you say to open as they are help closed by a spring and opened by a solenoid.
Something is stopping this from happening--the ecu which controls it all is fed by various engine sensors (MAF/temp/RPM etc) so go round these looking for obvious issues  (might be more relevant to poor running , not no running at all)

I would start by checking fuses to ecu/fuel related and think about swapping compatible relays (most solenoids will be working thru a relay)   related to the fuel system with similar ones from the relay /fuse box if you are lucky, or purchase from the likes of Tim Green
http://www.gsparkplug.com/

You say ignition is ok--so I assume you are getting a spark at the plugs, and fuel pump is ok. Assume the fuel tank can breathe  etc.

Good luck and keep us posted
Graham
nb I carry a complete set of main relays in my glove box as they are not that expensive.


MkIV Lux

Hi Graham,
Many thanks for the quick response.
Besides me, a car technician has made same checks as I did before.

All fuses in fuse box and ajacent OK.
Spark at the plug OK.
Tank can breathe, fuel available at the ramp.
Relays have been changed.

Are therer any "hidden" relays in other areas than the fuse box?
Does the ECU carry a fuse or two?

Could an immobilizer (Serpico car alarm) block a solenoid from working?

Wanted to be ready to go to Le Mans Classic in the Mk IV this Thursday, but am afraid I'll have to use another British car for the trip  :-\ :-\


Flyinghorse

#4
One thing that happened to a brooklands ace near me last year  was the inertia switch (fuel trip)  in the boot was triggered by a bump (its like a rollover/crash safety device) --It will be in the boot so check its not tripped. Will try to post a photo. I assume the Mkiv has one (my CRS and brooklands ace do). Its a small black plastic rectangular box with a red button most likley in top left wheel arch (NS)

Note reference to using a Noid light (basically pulses at the fuel injector in link in prev post by me (mustang forum)

B.P.Bird

Constant,
I know you have checked the fuses, but on 9520 I have suffered two obscure electrical faults which turned out to be nothing more than poor contacts between the fuse blades and the fuse holder. Because the contact was poor i.e. resistive, all kinds of inconclusive symptoms resulted. There is nothing to lose by removing one fuse at a time,cleaning the blades and then cleaning the holders with something like a nail file. A good spray with Electric Switch Cleaner and Water Dispersant will help.
I would pay particular attention to Fuse 18, 15 amp, 'Engine Run Relay Feed.' Then check the 'Engine Run Relay' itself - Relay VI . The blades and receptacles for the relays are not much better than for the fuses. I would agree with Graham that the relays are by no means 100% reliable  Of course the Fuse and Relay numbers might be different on your machine, but I think the functions will be there as they are part of the EEC IV system.
I think many functions are interlinked - when I could not start one day I happened to notice that everything on the dashboard was dead - Fuse 14 20 amp 'Dashboard - Ignition.' Obviously this affects other systems as the starter would not turn.
Finally you have probably disconnected and reconnected the multi pin connector on the EEC IV, if not nothing to lose.....
I do hope you can get the beast to behave in time for your run to le Mans
Good luck
Barrie

MkIV Lux

Many thanks Barrie,
I did some of it but not necessarily to the extent needed. But I checked all fuses and relays also with a simple light tester and found all lines in the fuse box area were hot when required.
I'll have to go through it again with the garage shop's technician, step by step.

I'm afraid though that it will not be done by tomorrow and will have to switch to the yellow mount for going to Le Mans.

Good night for now and we'll keep digging.
Constant

AC Ace Bristol

.
Constant

Good Luck with Diagnostics, Hopefully rectified and you travel To Le Mans Classic  in the MK1V,  You will be just as welcome in the yellow Lotus, or any other classic of your choice.
Give you a call later this morning.

Thank you for spotting the error in the road book , route to Chateau Grand Gaigne.

Keith

bobbylangley

Constant, I think I still have my old ecu around after having changed to carbs if it is any use?

MkIV Lux

Hi Bob,

Thanks for the suggestion.
Could indeed be of use, as mine might have a problem. Keep it safe for me please.
See you at Le Mans or will give you a ring.

Constant

MkIV Lux

Quote from: AC Ace Bristol on July 04, 2018, 00:26:06
.
Constant

Good Luck with Diagnostics, Hopefully rectified and you travel To Le Mans Classic  in the MK1V,  You will be just as welcome in the yellow Lotus, or any other classic of your choice.
Give you a call later this morning.

Thank you for spotting the error in the road book , route to Chateau Grand Gaigne.

Keith

Thanks Keith,
I'm afraid the Lotus will once more be the mount for the w/e.
Can't sort the MkIV trouble out, as busy day in the office is still top priority. Sources my income to enable me playing with classics  :) :)

Rob.Hendriks

Hi Constant
I'm probably a little late
Does the MKIV have an OBD port as part of the EEC-IV, if so have the codes been checked
Have you checked the PIP sensor (Profile Ignition Pickup) - if this has failed the injectors will not pulse. Note this is on a standard distributor
Have you checked the TPS voltage - I don't know the exact voltage for EEC-IV, but on my ECU, if it is above 1V it will not allow the injectors to pulse





MkIV Lux

Not too late Rob,
Many thanks for the hints.
I'm off to Le Mans and will start all over again in scientific documented approach to make sure we register what works and what does not.
I'll be back here early next week probably with more questions.
Cheers
Constant

Nev

Hi, PM sent, but I have a fault code reader for these, happy to plug it in, just a question of logistics,  but we may be able to sort something out.

Flyinghorse

Nev,
Is there any chance you can post pictures/details of your code reader. I have seem some Ford versions available in the US for reading EECIV but I have a feeling that as the EECIV cars get older folks are going to need to know how to troubleshoot and fix them/the system within the club.

Graham