Hello guys, newbie here, and I hope someone is able to help with my engine problem.

97' Expi 4x4, 4.6L with the 2 ignition coils at the front of the engine

It all started with the check engine light and the engine not running smoothly, no power. Diagnosis was misfire on cylinder 4, I then purchased a new ignition coil for the left cylinder bank.

I then took it in and they checked all the cables, cleaned the fuel delivery system, carburetor, all injectors, cleaned and flushed the tank and fuel lines, replaced fuel pump strainer and installed a new fuel filter.

After this was all done, suddenly there is a misfire on cylinders 3 and 7 (!), so on both banks and there is even less power. It is a really choppy ride to say the least. Cables look all good and tightly attached.

Any help is really appreciated and I thank you guys in advance!

 

I realize this can be an expensive route to go, but you should have to do this only once.
Since we don't know the full past history of the vehicle, I would suggest that you use Motorcraft parts . You do not need to purchase them from Ford.
Go the route and do it once.
Replace the coils, plugs and wires with Motorcraft parts. It is not the cheapest route to go , but you will do it once and be done.
If we keep hopping around and using lower priced parts we get what we pay for, most of the time.

 

Thanks for your reply, hanky. One coil is replaced already, with a quality part from Germany that cost only slightly less than the Motorcraft alternative. Will purchase some spark plugs now. Apart from that, do you think there could be another problem somewhere, just by the sound of it?

 

As you know , my hearing is not so good that I might be able to hear it from here,just kidding,
Something of which you should be aware;
misfires that cause the check engine light to illuminate are bad enough if correction is not done ASAP, can wipe out catalytic converters.and they are way more expensive than quality plugs, wires and coils.
If conditions permit and $$$ permits I would suggest don't wait, do the whole job and forget about it for a long while.

 

on the case. Thank you hanky!

 

 

Super old car and not the best gasoline quality here in the Philippines - they actually showed me the black "mud" they took out...

The engine runs very unsmoothly to say the least, the whole car is shaking heavily when idle. No power at all when accelerating, I struggle to drive uphills sometimes. When accelerating, it feels like there are "power intervals", i.e. for 2 seconds the engine has power, then less power, then 2 seconds power again, it's intermitting.

 

With the conditions described involving the fuel system anything is possible.
I am wondering , since the condition is intermittent could there be a loose wire or poor connection controlling the fuel system and/or the ign system?

If we could monitor the fuel pressure , that would tell us about the fuel supply at least up to the injectors.
With the new coil it should have eliminated cyls 1 thru 4. And still 4 was misfiring. Do you know when the plugs were replaced last?

 

Spark plugs were also replaced as one of the first things when the car started playing up - apologies, I already forgot about this since we have been working on this for a little while now!
I will make sure to have double checked all the cables again tomorrow, post any errors codes the repair shop can give me and I believe they are able to get a reading for the fuel pressure also. Once again, the car runs bad all the time now but there are times where it is really really bad - if that makes sense

About the coil - the one on the driver's side was replaced, which I believe controls cylinders 7, 2, 4 & 8. Misfiring now happens at cylinders 3 and 7, which makes me doubt the problem had anything to do at all with the coils.

 

This may or may not help, Ford numbers their cylinders 1 2 3 4 on the passenger side and 5 6 7 8on the driver's side.
Firing order is ; 1-3-7-2-6-5-4-8
The driver's side coil covers 2-7-4-8
pass side covers; 3-5-6-1

Who replaced the coil?