EA 3.9 motor randomly cutting out while driving - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Styles · 01-01-2005, 22:57

Hi All, I have posted the same in the Inline 6 Tech but I thought that you guys might also have a bit of knowledge in this as well.

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My EA 3.9 MPFI keeps cutting out at random times.

For example driving along the freeway at 110kms and all of a sudden the tacho registers 0 rpms then after about a second or two it starts up again and runs fine. It has also happened comming out of a round about at slow speed and also happened whilst ideling. It is happening at random, i.e. it is not just happening as I am comming out of a corner or just getting on the accelarator.

Today it decided to play up properly and for a while it did not want to idle at all after running the car at freeway conditions for about 30mins. For about 10 mins i had trouble keeping the engine running. Finally by the time I reached home the car was idleing properly and all was fine, wierd.

I have checked all electrical connections in the engine bay and under the car. After that thinking that it was a fuel quality problem ( it seemed like that anyway) I removed the old fuel filter and checked for any water or garbage (all was fine), replaced with a new one and also flushed the existing fuel out of the injector rail via the fuel pressure regulator and no water in there either and the problem is still happening.

I am guessing that it might be a sensor problem.

Any ideas would be great as I am a but sick of turning into a corner to realise that I have no power steering or engine power at all.

Thanks in advance

Bass Crazy · 01-01-2005, 23:02

Hey dude.

Just a thought. You might want to chack out or replace the ECU & Fuel pump relays located in the engine bay, beside the battery.
These have caused similar issues on 2 EA's I have worked on.

Simon

jjj · 01-01-2005, 23:16

Sounds like the tfi module on your dizzy is breaking down under heat. Get a new dizzy or 2nd hand one from the wreckers.

Cheers Luke

Styles · 01-01-2005, 23:31

Thanks,

Got any good ideas on how to actually get to the Dizzy easily in the MPFI model? Ford could have not hid it any better if they tried!

jjj · 01-01-2005, 23:39

undo the 2 bolts holding the isc on top of the throttle body and remove it. Easy to get to dizzy now and pull out.

cheers luke

Styles · 01-04-2005, 14:45

A bit of an update, I ran the self test diagnostics on the car using a multimeter etc, and I was getting an error code of 22 out of the continuous memory.
The manual explanation is that the MAP sensor is out of range. Could this be causing the engine to cut and if so is it just a case of replacing the MAP sensor or is there a way of fixing the sensor?

The vacuum line has no leaks, the MAP sensor seems to hold vacuum OK and the sensor is also receiving the required voltage from the plug as well.

Thanks

jjj · 01-07-2005, 18:37

Ignore those fault codes they can lead you down the garden path. The fault is your tfi module on your dizzy. The same thing happened to my car. It is a commom problem. Just unplug the hose to the map senor while engine is on, what happens? It runs like crap like it's on 4-5cyls but it does not cut out instantly which is what you are describing. It's your dizzy..................................

Cheers Luke

Styles · 01-09-2005, 13:20

Fair enough, TFI module will be replaced. You guy's know if you can remove the TFI without unbolting the dizzy? Or can you just lift the dizzy enough so that you can slide the TFI off without having the remove the intake manifold?
Thanks

EA1191 · 01-11-2005, 16:16

There was a random cutout problem with my EA which may have now gone, but never sure with these computer controled things. Nearly sure it was contaminated fuel. The shape of the fuel tank concentrates junk at the fuel intake and may have been water. Just a few drops would be enough.
Now use premium and think that the return valve in the pump may leak if it corrodes or is affected. That can make hot starts a problem.
Also had an intermittent steering pressure switch fault, which may have confused the computer. Shorted the terminals and no problems. Leaving it open gives an error code.

Scano · 01-11-2005, 16:30

sounds like the same thing that happend with my EA 5spd 3.9mpi theres a hose running from the inlet manifold to a MAP sensor its up agaisnt the firewall and its a little black box bit bigger than a matchbox with a few hoses and wires, the hose from the manifold fell out of the box, i put it back on and zip tied it cause i didnt have time to get to the wreckers, she wouldnt hold idle, really rough when i was driving, and kept having flat spots when i would punch it