I have a Ford Sierra that has been retro fitted with the 2.0l twin cam EFI engine. I4 ?

It has been laid up for over 3 years, Ran fine when it was last on the road , had a tiny flat spot on the throttle that was a bit of a pain cruising a low speed but not that bad.

Now if & when it starts , the engine seems to suit itself how it runs.
Sometimes happy to tick over for ages, touch the throttle & it will miss fire like a pig.

Started it this morning, struggle to get her to idle at all. will not stop spluttering until about 3500 rpm. release the throttle & it will idle at 2000rpm for a while then cough & splutter , then stall or tick over on what seems to be 2 cylinders.

In general I would say that it has a miss fire on 1-2 cylinders most of the time.

Back story: Running fine 18 months ago purring away as it should.
The fuel was very low so a grabbed a 10L can of clean unused fuel from my boat.
No more than 4 months old.
Filled her up whilst the engine was running, car instantly coughed & farted then stalled, Refused to restart.
Car has not run right ever since.

No real logic as to why it should have done that as I know the fuel was clean & good. in fact it was the same fuel that still run my boat engine the following year.

Things I have tried.
Cleaned the plugs
Checked for vac leaks
swapped coil for known good
swapped idle control unit for another
visual check on the fuel pressure regulator ( As per BT's great link )
Cleaned rotor arm & dizzy cap

Having convinced myself it is a fuel problem, yesterday I bypassed the fuel tank.
Fed fuel via a high pressure pump + new filter unit
Jury rigged to a spare battery & fuel from a 10L can of new fuel

Fresh fuel from the can to the fuel rail & return pipe going back to my jury can.

Still running rough & I am full out of ideas as to where to go next.

Any advice would be much appreciated.

ETA
The battery has been dead flat a good few times during the last few years.
Is it likely to have damaged the ecu in some way ? ( I have a spare )

[Edited on 18/6/17 by bonzoronnie]

[Edited on 18/6/17 by bonzoronnie]

[Edited on 18/6/17 by bonzoronnie]

Modern plugs don't like being fouled, my first port of call would be to fit new plugs and perhaps new leads? Might also be worth trying a bottle of injector cleaner, had problems after a long lay up with my car ,ended up taking the injectors out and flushing through a very strong mixture of 3 bottles of injector cleaner and 5 litres of fuel

I guess it would be logical to pop a new set of plugs in.

Feeling foolish now , I have injector cleaner in the workshop. Could have put that in the can yesterday.
Never gave it a thought.

Okay I don't know the system on these engines but it looks like the fuel side is the first thing to look at, the problem is there is no easy electronic diagnostic method on the engine. I suspect sticking injector(s) if I were looking at the car I would open my big box of diagnostic gear and do an injector balance test. However before doing that I would check fo vacuum leaks, clean the throttle body and idle control valve and visually inspect the engine wiring.


The electronic tool and the gauge required for checking the fuel injector balance aren't injectors aren't that expensive so perhaps worth considering.



EFI Petrol Fuel Injector Tester 12v system Diagnose problems Inc Store Case 3422





Fuel Injection Pressure Tester Car Tool Kit Ford Vauxhall GM Test Port Schroder

Thank you for those links BT.
Very informative as usual.

I am up for any excuse to add to my tool collection.

My gut feeling is fuel rather than electrical.

When all 4 cylinders fire the engine sounds perfectly normal.

Id hazzard a guess when you put the fresh (ish) fuel in you stirred all the sedimented crap up in the tank and that has found its way to the injectors, there may also be bits of degraded fuel hose in the mix too.