302 EFI Engine refrains from starting

[Nev]

I have the unit that was used to test the cars at the factory, before they went out, it is a Ford branded Rotunda unit. Hand-held and in a case. Also I have the codes definitions etc. Etc .........

[MkIV Lux]

A Ford Mustang specialist (with experience on 90's cars) in nearby Germany whom I consulted by phone told me that the ECU can only be read when engine running...
True?

[Nev]

Not sure, but I can certainly test that out on mine and confirm.........

So, the 'Star' reader only seems to do diagnostics with engine running.
I also have a small code reader, Equus 3007, ECM Code Reader, which reads both ign on, and also with engine running,  ut i am not sure if this is the right reader for these cars, it says for Ford 1981 onwards.

I have just found this thread, which may be handy?
https://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4-in-86-95-5-0-mustangs.889006/

[MkIV Lux]

The situation is currently as follows:

- after having (re)checked all electrical circuits, not being able to read the ECU though (as no corresponding program/hardware available), I had asked the garage to recheck the fuel pressure at the ramp. Fuel pressure at the ramp is crucial to command the injectors;
- ultimately they found out that at least one on the pumps is dead (previously when turning ignition key and cranking the engine, one heard the pump work, without being able to tell if all pumps work, so wrongly assuming that pumps were working; fuel was available at the ramp, but fuel pressure had not been checked);  now they checked more thoroughly actually feeling the pumps while having ignition on!

- so one of the LP pumps being dead, I decided to replace the 2 LP pumps before going any further and swapping ECU's;

- in this process I found out actually that there is not only one pump, but 3 as on the attached fuel system diagram (may be incomplete).

- have ordered the pumps last Monday from www.competitionsupplies.com in Silverstone, pumps and fittings arrived Thursday and they will be mounted today.

..... so let's wait and see what it will bring

[Rob.Hendriks]

That appears to be a strange setup
The red tops are a high flow (150lph), low pressure pump (6-8psi). Most EFI systems require 200lph+ and 40-45psi, so presumably the 3rd pump is used to boost the flow and pressure
Looks like a carburetted system that has been upgraded to EFI

[MkIV Lux]

That appears to be a strange setup
The red tops are a high flow (150lph), low pressure pump (6-8psi). Most EFI systems require 200lph+ and 40-45psi, so presumably the 3rd pump is used to boost the flow and pressure
Looks like a carburetted system that has been upgraded to EFI

Hi Rob,
Maybe strange set-up but easily traceable as to its origins, as per AC Autokraft production spec sheet (which I have):
- the car is a LW chassis AKL
- had been ordered originally for a customer in the Far East (some time late 1991 early 1992); exact spec however unknown to me;
- this deal fell through (reason unknown)
- car was then assigned to a German customer which led to a number of modifications recorded on the production spec sheet: under "1st Updates required at 5th July 1992": a list of some 33 modifications starting with: "Car to be altered to meet German TÜV approval" - under these: "Fit Jaguar fuel cap assembly, update fuel pump system to three pump system" ......
- completion date of the car is 28 July 1993; production spec sheet printed on 4 August 1993.

[Rob.Hendriks]

not even going to ask why.....

[MkIV Lux]

The Mk IV is running  again   :) :) :) :) :)  happy me!

I'll get back with a report shortly.

Many thanks to all for your precious hints, suggestions and help with hardware.

Constant

[TTM]

Good morning,

I would suggest replacing all 3 pumps with a suitable single high pressure pump and add a pressure gauge on the fuel ramp and a fuel pressure regulator, as I think it's the right way to run an EFI set up with minimum headaches.
I have been running a Bosch 044 pump on a car that makes 450hp with 1200cc injectors running at 60% duty cycle, so got plenty of room left for more power and never run into fueling issues whatsoever in all possible weather conditions one could imagine (bar a hurricane).

I think that running 3 pumps is asking for troubles. It probably works but I find this particularly idiotic, especially when a single pump these days can do the same job on a relatively unstressed 302ci normally-aspirated engine.

[MkIV Lux]

you might be right, TTM, but sofar my mount travelled some 78000 kms over 25 years throughout Europe (of which the first 2 owners only had covered 11.000 kms in the first 9 years of the Mk IV's life), in all weather conditions, faultlessly, never missing a beat. I was even not aware of the 3 pump system, as all had been working fine all the time. So maybe next time I'll encounter problems, I will think twice about it ...

[TTM]

Mine has done 380000 km in 28 years - Your mileage may vary... pun intended  ;)

[MkIV Lux]

Mine has done 380000 km in 28 years - Your mileage may vary... pun intended  ;)

what car is that ?

[MkIV Lux]

Did I forget to mention on this thread that meanwhile the Mk IV runs, after having installed new LP pumps and exchanged  the deficient ECU against a working element from a similar car. The ECU had one transistor burned on the path governing negative return to command the pump relay and the injectors. (Not sure this is correctly explained).
Need to find a replacement ECU with D3D code (programmed for a specitic application/destination market). If anyone would have such sitting around, thanks for contacting me via PM.

Thanks to all who gave me a precious hint to get to the solution of this problem.
Constant

[B.P.Bird]

Constant,
This will be a problem we will all face over the coming years - Ford will not supply replacement EEC IV units for ever, maybe they already stopped ? In any event a quick look on the internet revealed a number of companies offering repairs so maybe your best move would be to investigate a repair to your failed EEC ? http://www.ecu-repairs.com/engine-ecu-repairs/ford. We should all benefit from your experience
There are, of course, alternative tuneable after market ECUs, but this is not a simple 'plug and play' swop.....

[MkIV Lux]

Hi Barrie,
Indeed that is exactly what I am doing now. Get my ECU repaired. There is a local company doing such repairs and we wait to have the ECU back.
On the w/e at a local exhibition which I attended with my friend Jean (owner of an early Mk IV with Weber carbs),  I ran into another local garage shop owner who works on period Mustangs and he told me he has all the equipment to reprogram theses Ford ECUs, so would be able to read-out the configuration on my original repaired ECU and copy same configuration on a replacement ECU. Possibly also alter the config.

I'll go and see him when the original is back from repair.